pax_global_header 0000666 0000000 0000000 00000000064 12750641745 0014525 g ustar 00root root 0000000 0000000 52 comment=798a16982da0fa4b6fd7f20b75c5cb92b5af8141
ZODB-5.0.0b1/ 0000775 0000000 0000000 00000000000 12750641745 0012510 5 ustar 00root root 0000000 0000000 ZODB-5.0.0b1/.coveragerc 0000664 0000000 0000000 00000000254 12750641745 0014632 0 ustar 00root root 0000000 0000000 [run]
# source = ...
# omit = ...
# cover_pylib = False
# branch = True
[report]
exclude_lines =
pragma: nocover
if __name__ == ['"]__main__['"]:
assert False
ZODB-5.0.0b1/.gitignore 0000664 0000000 0000000 00000000266 12750641745 0014504 0 ustar 00root root 0000000 0000000 bin
eggs
develop-eggs
parts
.installed.cfg
build
docs/_build
__pycache__
*.pyc
*.so
.tox
.coverage
nosetests.xml
coverage.xml
*.egg-info
*.egg
dist
testing.log
.eggs/
.dir-locals.el
ZODB-5.0.0b1/.travis.yml 0000664 0000000 0000000 00000002177 12750641745 0014630 0 ustar 00root root 0000000 0000000 language: python
sudo: false
python:
- pypy
- pypy3
- 2.7
- 3.3
- 3.4
- 3.5
install:
# First install a newer pip so that it can use the wheel cache
# (only needed until travis upgrades pip to 7.x; note that the 3.5
# environment uses pip 7.1 by default).
- travis_retry pip install -U pip
# A newer wheel is also needed under Python 3, but only after we have
# a newer pip to take advantage of the cache.
- travis_retry pip install -U wheel
# Then start installing our deps so they can be cached. Note that use of --build-options / --global-options / --install-options
# disables the cache.
- travis_retry pip install -U manuel zope.testing zope.testrunner
- travis_retry pip install -U -e .
script:
- zope-testrunner -u --test-path=src --auto-color --auto-progress
- zope-testrunner -f --test-path=src --auto-color --auto-progress
notifications:
email: false
# cache: pip seems not to work if `install` is replaced (https://github.com/travis-ci/travis-ci/issues/3239)
cache:
directories:
- $HOME/.cache/pip
before_cache:
- rm -f $HOME/.cache/pip/log/debug.log
ZODB-5.0.0b1/3.11.txt 0000664 0000000 0000000 00000003411 12750641745 0013632 0 ustar 00root root 0000000 0000000 Wish list for 3.11.
These aren't promises, but things I'd like to do:
- ZEO support for loading blobs via HTTP.
- ZEO cache fix for loadBefore.
- invalidation events.
- Make DBs context manager, so in a simple script, one could do:
with ZEO.DB(someaddr) as connection:
do some things in a transaction. Commit and close at the end.
- Persistent sets.
- PxBTrees, persistent objects as keys in BTrees.
- Compare on persistent references.
- Python BTrees and persistence.
- JSONic read-only mode where you can read most objects for which you
don't have classes as long at they have the default getstate.
This might be as simple as using a variation of broken objects.
- persistent.Object, which handles the common case of a simple object
that just has some data. (The moral equivalent of a JS object. :)
- API to preload objects.
Say you know you're going to oterate over an array of objects, you
might signal that intend to use the object with something like::
for oject in objects:
object._p_will_use()
(I think there's an RFC for something like this.)
For most storages, _p_will_use won't have any effect, but for ZEO,
it could cause a load request to be sent to the server if the object
isn't already loaded or in the zeo cache. This way, you could have
lots of loads in flight at once, mitigating round-trip costs.
- ZEO cache iterator, to facilitate analysis of cache contents.
- Update file-storage iterator to expose file position as non-private
var for transactions and database records.
Expose trans size.
- Update ZEO ClientStorage to block for soem short time rather than
error on short disconnection.
- Remove silly ZEO connection backooff by default.
- Rewrite ZEO connection logic using async IO rather than threads.
ZODB-5.0.0b1/CHANGES.rst 0000664 0000000 0000000 00000022517 12750641745 0014321 0 ustar 00root root 0000000 0000000 ================
Change History
================
5.0.0b1 (2016-08-04)
====================
- fstail: print the txn offset and header size, instead of only the data offset.
fstail can now be used to truncate a DB at the right offset.
Numerous internal cleanups, including:
- Changed the way the root object was created. Now the root object is
created using a database connection, rather than by making low-level
storage calls.
- Drop support for the old commit protocol.
- Internal FileStorage-undo fixes that should allow undo in some cases
where it didn't work before.
- Drop the ``version`` argument to some methods where it was the last
argument and optional.
5.0.0a6 (2016-07-21)
====================
- Added a connection ``prefetch`` method that can be used to request
that a storage prefect data an application will need::
conn.prefetch(obj, ...)
Where arguments can be objects, object ids, or iterables of objects
or object ids.
Added optional ``prefetch`` methods to the storage APIs. If a
storage doesn't support prefetch, then the connection prefetch
method is a noop.
5.0.0a5 (2016-07-06)
====================
Drop support for old commit protocol. All of the build-in storages
implement the new protocol. This new protocol allows storages to
provide better write performance by allowing multiple commits to
execute in parallel.
5.0.0a4 (2016-07-05)
====================
See 4.4.2.
5.0.0a3 (2016-07-01)
====================
See 4.4.1.
5.0.0a2 (2016-07-01)
====================
See 4.4.0.
5.0.0a1 (2016-06-20)
====================
Major **internal** implementation changes to the Multi Version
Concurrency Control (MVCC) implementation:
- For storages that implement IMVCCStorage (RelStorage), no longer
implement MVCC in ZODB.
- For other storages, MVCC is implemented using an additional storage
layer. This underlying layer works by calling ``loadBefore``. The
low-level storage ``load`` method isn't used any more.
This change allows server-nased storages like ZEO and NEO to be
implemented more simply and cleanly.
4.4.3 (2016-08-04)
==================
- Internal FileStorage-undo fixes that should allow undo in some cases
where it didn't work before.
- fstail: print the txn offset and header size, instead of only the data offset.
fstail can now be used to truncate a DB at the right offset.
4.4.2 (2016-07-08)
==================
Better support of the new commit protocol. This fixes issues with blobs and
undo. See pull requests #77, #80, #83
4.4.1 (2016-07-01)
==================
Added IMultiCommitStorage to directly represent the changes in the 4.4.0
release and to make complient storages introspectable.
4.4.0 (2016-06-30)
==================
This release begins evolution to a more effcient commit protocol that
allows storage implementations, like `NEO `_,
to support multiple transactions committing at the same time, for
greater write parallelism.
This release updates IStorage:
- The committed transaction's ID is returned by ``tpc_finish``, rather
than being returned in response store and tpc_vote results.
- ``tpc_vote`` is now expected to return ``None`` or a list of object
ids for objects for which conflicts were resolved.
This release works with storages that implemented the older version of
the storage interface, but also supports storages that implement the
updated interface.
4.3.1 (2016-06-06)
==================
- Fixed: FileStorage loadBefore didn't handle deleted/undone data correctly.
4.3.0 (2016-05-31)
==================
- Drop support for Python 2.6 and 3.2.
- Make the ``zodbpickle`` dependency required and not conditional.
This fixes various packaging issues involving pip and its wheel
cache. zodbpickle was only optional under Python 2.6 so this change
only impacts users of that version. See
https://github.com/zopefoundation/ZODB/pull/42.
- Add support for Python 3.5.
- Avoid failure during cleanup of nested databases that provide MVCC
on storage level (Relstorage).
https://github.com/zopefoundation/ZODB/issues/45
- Remove useless dependency to `zdaemon` in setup.py. Remove ZEO documentation.
Both were leftovers from the time where ZEO was part of this repository.
- Fix possible data corruption after FileStorage is truncated to roll back a
transaction.
https://github.com/zopefoundation/ZODB/pull/52
- DemoStorage: add support for conflict resolution and fix history()
https://github.com/zopefoundation/ZODB/pull/58
- Fixed a test that depended on implementation-specific behavior in tpc_finish
4.2.0 (2015-06-02)
==================
- Declare conditional dependencies using PEP-426 environment markers
(fixing interation between pip 7's wheel cache and tox). See
https://github.com/zopefoundation/ZODB/issues/36.
4.2.0b1 (2015-05-22)
====================
- Log failed conflict resolution attempts at ``DEBUG`` level. See:
https://github.com/zopefoundation/ZODB/pull/29.
- Fix command-line parsing of ``--verbose`` and ``--verify`` arguments.
(The short versions, ``-v`` and ``-V``, were parsed correctly.)
- Add support for PyPy.
- Fix the methods in ``ZODB.serialize`` that find object references
under Python 2.7 (used in scripts like ``referrers``, ``netspace``,
and ``fsrecover`` among others). This requires the addition of the
``zodbpickle`` dependency.
- FileStorage: fix an edge case when disk space runs out while packing,
do not leave the ``.pack`` file around. That would block any write to the
to-be-packed ``Data.fs``, because the disk would stay at 0 bytes free.
See https://github.com/zopefoundation/ZODB/pull/21.
4.1.0 (2015-01-11)
==================
- Fix registration of custom logging level names ("BLATHER", "TRACE").
We have been registering them in the wrong order since 2004. Before
Python 3.4, the stdlib ``logging`` module masked the error by registering
them in *both* directions.
- Add support for Python 3.4.
4.0.1 (2014-07-13)
==================
- Fix ``POSKeyError`` during ``transaction.commit`` when after
``savepoint.rollback``. See
https://github.com/zopefoundation/ZODB/issues/16
- Ensure that the pickler used in PyPy always has a ``persistent_id``
attribute (``inst_persistent_id`` is not present on the pure-Python
pickler). (PR #17)
- Provide better error reporting when trying to load an object on a
closed connection.
4.0.0 (2013-08-18)
==================
Finally released.
4.0.0b3 (2013-06-11)
====================
- Switch to using non-backward-compatible pickles (protocol 3, without
storing bytes as strings) under Python 3. Updated the magic number
for file-storage files under Python3 to indicate the incompatibility.
- Fixed: A ``UnicodeDecodeError`` could happen for non-ASCII OIDs
when using bushy blob layout.
4.0.0b2 (2013-05-14)
====================
- Extended the filename renormalizer used for blob doctests to support
the filenames used by ZEO in non-shared mode.
- Added ``url`` parameter to ``setup()`` (PyPI says it is required).
4.0.0b1 (2013-05-10)
=====================
- Skipped non-unit tests in ``setup.py test``. Use the buildout to run tests
requiring "layer" support.
- Included the filename in the exception message to support debugging in case
``loadBlob`` does not find the file.
- Added support for Python 3.2 / 3.3.
.. note::
ZODB 4.0.x is supported on Python 3.x for *new* applications only.
Due to changes in the standard library's pickle support, the Python3
support does **not** provide forward- or backward-compatibility
at the data level with Python2. A future version of ZODB may add
such support.
Applications which need migrate data from Python2 to Python3 should
plan to script this migration using separte databases, e.g. via a
"dump-and-reload" approach, or by providing explicit fix-ups of the
pickled values as transactions are copied between storages.
4.0.0a4 (2012-12-17)
=====================
- Enforced usage of bytes for ``_p_serial`` of persistent objects (fixes
compatibility with recent persistent releases).
4.0.0a3 (2012-12-01)
=====================
- Fixed: An elaborate test for trvial logic corrupted module state in a
way that made other tests fail spuriously.
4.0.0a2 (2012-11-13)
=====================
Bugs Fixed
----------
- An unneeded left-over setting in setup.py caused installation with
pip to fail.
4.0.0a1 (2012-11-07)
=====================
New Features
------------
- The ``persistent`` and ``BTrees`` packages are now released as separate
distributions, on which ZODB now depends.
- ZODB no longer depends on zope.event. It now uses ZODB.event, which
uses zope.event if it is installed. You can override
ZODB.event.notify to provide your own event handling, although
zope.event is recommended.
- BTrees allowed object keys with insane comparison. (Comparison
inherited from object, which compares based on in-process address.)
Now BTrees raise TypeError if an attempt is made to save a key with
comparison inherited from object. (This doesn't apply to old-style
class instances.)
Bugs Fixed
----------
- Ensured that the export file and index file created by ``repozo`` share
the same timestamp.
https://bugs.launchpad.net/zodb/+bug/993350
- Pinned the ``transaction`` and ``manuel`` dependencies to Python 2.5-
compatible versions when installing under Python 2.5.
.. note::
Please see ``doc/HISTORY.txt`` for changelog entries for older versions
of ZODB.
ZODB-5.0.0b1/COPYING 0000664 0000000 0000000 00000000133 12750641745 0013540 0 ustar 00root root 0000000 0000000 See:
- the copyright notice in: COPYRIGHT.txt
- The Zope Public License in LICENSE.txt
ZODB-5.0.0b1/COPYRIGHT.txt 0000664 0000000 0000000 00000000040 12750641745 0014613 0 ustar 00root root 0000000 0000000 Zope Foundation and Contributors ZODB-5.0.0b1/HISTORY.txt 0000664 0000000 0000000 00000462531 12750641745 0014425 0 ustar 00root root 0000000 0000000
3.9.7 (2010-09-28)
==================
Bugs Fixed
----------
- Changes in way that garbage collection treats dictionaries in Python
2.7 broke the object/connection cache implementation.
(https://bugs.launchpad.net/zodb/+bug/641481)
Python 2.7 wasn't officially supported, but we were releasing
binaries for it, so ...
- Logrotation/repoening via a SIGUSR2 signal wasn't implemented.
(https://bugs.launchpad.net/zodb/+bug/143600)
- When using multi-databases, cache-management operations on a
connection, cacheMinimize and cacheGC, weren't applied to
subconnections.
3.9.6 (2010-09-21)
==================
Bugs Fixed
----------
- Updating blobs in save points could cause spurious "invalidations
out of order" errors. https://bugs.launchpad.net/zodb/+bug/509801
(Thanks to Christian Zagrodnick for chasing this down.)
- If a ZEO client process was restarted while invalidating a ZEO cache
entry, the cache could be left in a stage when there is data marked
current that should be invalidated, leading to persistent conflict
errors.
- Corrupted or invalid cache files prevented ZEO clients from
starting. Now, bad cache files are moved aside.
- Invalidations of object records in ZEO caches, where the
invalidation transaction ids matched the cached transaction ids
should have been ignored.
- Shutting down a process while committing a transaction or processing
invalidations from the server could cause ZEO persistent client
caches to have invalid data. This, in turn caused stale data to
remain in the cache until it was updated.
- Conflict errors didn't invalidate ZEO cache entries.
- When objects were added in savepoints and either the savepoint was
rolled back (https://bugs.launchpad.net/zodb/+bug/143560) or the
transaction was aborted
(https://mail.zope.org/pipermail/zodb-dev/2010-June/013488.html)
The objects' _p_oid and _p_jar variables weren't cleared, leading to
surprizing errors.
- Objects added in transactions that were later aborted could have
_p_changed still set (https://bugs.launchpad.net/zodb/+bug/615758).
- ZEO extension methods failed when a client reconnected to a
storage. (https://bugs.launchpad.net/zodb/+bug/143344)
- On Mac OS X, clients that connected and disconnected quickly could
cause a ZEO server to stop accepting connections, due to a failure
to catch errors in the initial part of the connection process.
The failure to properly handle exceptions while accepting
connections is potentially problematic on other platforms.
Fixes: https://bugs.launchpad.net/zodb/+bug/135108
- Passing keys or values outside the range of 32-bit ints on 64-bit
platforms led to undetected overflow errors. Now these cases cause
Type errors to be raised.
https://bugs.launchpad.net/zodb/+bug/143237
- BTree sets and tree sets didn't correctly check values passed to
update or to constructors, causing Python to exit under certain
circumstances.
- The verbose mode of the fstest was broken.
(https://bugs.launchpad.net/zodb/+bug/475996)
3.9.5 (2010-04-23)
==================
Bugs Fixed
----------
- Fixed bug in cPickleCache's byte size estimation logic.
(https://bugs.launchpad.net/zodb/+bug/533015)
- Fixed a serious bug that caused cache failures when run
with Python optimization turned on.
https://bugs.launchpad.net/zodb/+bug/544305
- Fixed a bug that caused savepoint rollback to not properly
set object state when objects implemented _p_invalidate methods
that reloaded ther state (unghostifiable objects).
https://bugs.launchpad.net/zodb/+bug/428039
- cross-database wekrefs weren't handled correctly.
https://bugs.launchpad.net/zodb/+bug/435547
- The mkzeoinst script was fixed to tell people to
install and use the mkzeoinstance script. :)
3.9.4 (2009-12-14)
==================
Bugs Fixed
----------
- A ZEO threading bug could cause transactions to read inconsistent
data. (This sometimes caused an AssertionError in
Connection._setstate_noncurrent.)
- DemoStorage.loadBefore sometimes returned invalid data which
would trigger AssertionErrors in ZODB.Connection.
- History support was broken when using stprages that work with ZODB
3.8 and 3.9.
- zope.testing was an unnecessary non-testing dependency.
- Internal ZEO errors were logged at the INFO level, rather
than at the error level.
- The FileStorage backup and restore script, repozo, gave a
deprecation warning under Python 2.6.
- C Header files weren't installed correctly.
- The undo implementation was incorrect in ways that could cause
subtle missbehaviors.
3.9.3 (2009-10-23)
==================
Bugs Fixed
----------
- 2 BTree bugs, introduced by a bug fix in 3.9.0c2, sometimes caused
deletion of keys to be improperly handled, resulting in data being
available via iteraation but not item access.
3.9.2 (2009-10-13)
==================
Bugs Fixed
----------
- ZEO manages a separate thread for client network IO. It created
this thread on import, which caused problems for applications that
implemented daemon behavior by forking. Now, the client thread
isn't created until needed.
- File-storage pack clean-up tasks that can take a long time
unnecessarily blocked other activity.
- In certain rare situations, ZEO client connections would hang during
the initial connection setup.
3.9.1 (2009-10-01)
==================
Bugs Fixed
----------
- Conflict errors committing blobs caused ZEO servers to stop committing
transactions.
3.9.0 (2009-09-08)
==================
New Features (in more or less reverse chronological order)
----------------------------------------------------------
- The Database class now has an ``xrefs`` keyword argument and a
corresponding allow-implicit-cross-references configuration option.
which default to true. When set to false, cross-database references
are disallowed.
- Added support for RelStorage.
- As a convenience, the connection root method for returning the root
object can now *also* be used as an object with attributes mapped to
the root-object keys.
- Databases have a new method, ``transaction``, that can be used with the
Python (2.5 and later) ``with`` statement::
db = ZODB.DB(...)
with db.transaction() as conn:
# ... do stuff with conn
This uses a private transaction manager for the connection.
If control exits the block without an error, the transaction is
committed, otherwise, it is aborted.
- Convenience functions ZODB.connection and ZEO.connection provide a
convenient way to open a connection to a database. They open a
database and return a connection to it. When the connection is
closed, the database is closed as well.
- The ZODB.config databaseFrom... methods now support
multi-databases. If multiple zodb sections are used to define
multiple databases, the databases are connected in a multi-database
arrangement and the first of the defined databases is returned.
- The zeopack script has gotten a number of improvements:
- Simplified command-line interface. (The old interface is still
supported, except that support for ZEO version 1 servers has been
dropped.)
- Multiple storages can be packed in sequence.
- This simplifies pack scheduling on servers serving multiple
databases.
- All storages are packed to the same time.
- You can now specify a time of day to pack to.
- The script will now time out if it can't connect to s storage in
60 seconds.
- The connection now estimates the object size based on its pickle size
and informs the cache about size changes.
The database got additional configurations options (`cache-size-bytes`
and `historical-cache-size-bytes`) to limit the
cache size based on the estimated total size of cached objects.
The default values are 0 which has the interpretation "do not limit
based on the total estimated size".
There are corresponding methods to read and set the new configuration
parameters.
- Connections now have a public ``opened`` attribute that is true when
the connection is open, and false otherwise. When true, it is the
seconds since the epoch (time.time()) when the connection was
opened. This is a renaming of the previous ``_opened`` private
variable.
- FileStorage now supports blobs directly.
- You can now control whether FileStorages keep .old files when packing.
- POSKeyErrors are no longer logged by ZEO servers, because they are
really client errors.
- A new storage interface, IExternalGC, to support external garbage
collection, http://wiki.zope.org/ZODB/ExternalGC, has been defined
and implemented for FileStorage and ClientStorage.
- As a small convenience (mainly for tests), you can now specify
initial data as a string argument to the Blob constructor.
- ZEO Servers now provide an option, invalidation-age, that allows
quick verification of ZEO clients have been disconnected for less
than a given time even if the number of transactions the client
hasn't seen exceeds the invalidation queue size. This is only
recommended if the storage being served supports efficient iteration
from a point near the end of the transaction history.
- The FileStorage iterator now handles large files better. When
iterating from a starting transaction near the end of the file, the
iterator will scan backward from the end of the file to find the
starting point. This enhancement makes it practical to take
advantage of the new storage server invalidation-age option.
- Previously, database connections were managed as a stack. This
tended to cause the same connection(s) to be used over and over.
For example, the most used connection would typically be the only
connection used. In some rare situations, extra connections could
be opened and end up on the top of the stack, causing extreme memory
wastage. Now, when connections are placed on the stack, they sink
below existing connections that have more active objects.
- There is a new pool-timeout database configuration option to specify that
connections unused after the given time interval should be garbage
collection. This will provide a means of dealing with extra
connections that are created in rare circumstances and that would
consume an unreasonable amount of memory.
- The Blob open method now supports a new mode, 'c', to open committed
data for reading as an ordinary file, rather than as a blob file.
The ordinary file may be used outside the current transaction and
even after the blob's database connection has been closed.
- ClientStorage now provides blob cache management. When using
non-shared blob directories, you can set a target cache size and the
cache will periodically be reduced try to keep it below the target size.
The client blob directory layout has changed. If you have existing
non-shared blob directories, you will have to remove them.
- ZODB 3.9 ZEO clients can connect to ZODB 3.8 servers. ZODB ZEO clients
from ZODB 3.2 on can connect to ZODB 3.9 servers.
- When a ZEO cache is stale and would need verification, a
ZEO.interfaces.StaleCache event is published (to zope.event).
Applications may handle this event and take action such as exiting
the application without verifying the cache or starting cold.
- There's a new convenience function, ZEO.DB, for creating databases
using ZEO Client Storages. Just call ZEO.DB with the same arguments
you would otherwise pass to ZEO.ClientStorage.ClientStorage::
import ZEO
db = ZEO.DB(('some_host', 8200))
- Object saves are a little faster
- When configuring storages in a storage server, the storage name now
defaults to "1". In the overwhelmingly common case that a single
storage, the name can now be omitted.
- FileStorage now provides optional garbage collection. A 'gc'
keyword option can be passed to the pack method. A false value
prevents garbage collection.
- The FileStorage constructor now provides a boolean pack_gc option,
which defaults to True, to control whether garbage collection is
performed when packing by default. This can be overridden with the
gc option to the pack method.
The ZConfig configuration for FileStorage now includes a pack-gc
option, corresponding to the pack_gc constructor argument.
- The FileStorage constructor now has a packer keyword argument that
allows an alternative packer to be supplied.
The ZConfig configuration for FileStorage now includes a packer
option, corresponding to the packer constructor argument.
- MappingStorage now supports multi-version concurrency control and
iteration and provides a better storage implementation example.
- DemoStorage has a number of new features:
- The ability to use a separate storage, such as a file storage to
store changes
- Blob support
- Multi-version concurrency control and iteration
- Explicit support for demo-storage stacking via push and pop methods.
- Wen calling ZODB.DB to create a database, you can now pass a file
name, rather than a storage to use a file storage.
- Added support for copying and recovery of blob storages:
- Added a helper function, ZODB.blob.is_blob_record for testing whether
a data record is for a blob. This can be used when iterating over a
storage to detect blob records so that blob data can be copied.
In the future, we may want to build this into a blob-aware
iteration interface, so that records get blob file attributes
automatically.
- Added the IBlobStorageRestoreable interfaces for blob storages
that support recovery via a restoreBlob method.
- Updated ZODB.blob.BlobStorage to implement
IBlobStorageRestoreable and to have a copyTransactionsFrom method
that also copies blob data.
- New `ClientStorage` configuration option `drop_cache_rather_verify`.
If this option is true then the ZEO client cache is dropped instead of
the long (unoptimized) verification. For large caches, setting this
option can avoid effective down times in the order of hours when
the connection to the ZEO server was interrupted for a longer time.
- Cleaned-up the storage iteration API and provided an iterator implementation
for ZEO.
- Versions are no-longer supported.
- Document conflict resolution (see ZODB/ConflictResolution.txt).
- Support multi-database references in conflict resolution.
- Make it possible to examine oid and (in some situations) database
name of persistent object references during conflict resolution.
- Moved the 'transaction' module out of ZODB.
ZODB depends upon this module, but it must be installed separately.
- ZODB installation now requires setuptools.
- Added `offset` information to output of `fstail`
script. Added test harness for this script.
- Added support for read-only, historical connections based
on datetimes or serials (TIDs). See
src/ZODB/historical_connections.txt.
- Removed the ThreadedAsync module.
- Now depend on zc.lockfile
Bugs Fixed
----------
- CVE-2009-2701: Fixed a vulnerability in ZEO storage servers when
blobs are available. Someone with write access to a ZEO server
configured to support blobs could read any file on the system
readable by the server process and remove any file removable by the
server process.
- BTrees (and TreeSets) kept references to internal keys.
https://bugs.launchpad.net/zope3/+bug/294788
- BTree Sets and TreeSets don't support the standard set add method.
(Now either add or the original insert method can be used to add an
object to a BTree-based set.)
- The runzeo script didn't work without a configuration file.
(https://bugs.launchpad.net/zodb/+bug/410571)
- Officially deprecated PersistentDict
(https://bugs.launchpad.net/zodb/+bug/400775)
- Calling __setstate__ on a persistent object could under certain
uncommon cause the process to crash.
(https://bugs.launchpad.net/zodb/+bug/262158)
- When committing transactions involving blobs to ClientStorages with
non-shared blob directories, a failure could occur in tpc_finish if
there was insufficient disk space to copy the blob file or if the
file wasn't available. https://bugs.launchpad.net/zodb/+bug/224169
- Savepoint blob data wasn't properly isolated. If multiple
simultaneous savepoints in separate transactions modified the same
blob, data from one savepoint would overwrite data for another.
- Savepoint blob data wasn't cleaned up after a transaction abort.
https://bugs.launchpad.net/zodb/+bug/323067
- Opening a blob with modes 'r+' or 'a' would fail when the blob had no
committed changes.
- PersistentList's sort method did not allow passing of keyword parameters.
Changed its sort parameter list to match that of its (Python 2.4+)
UserList base class.
- Certain ZEO server errors could cause a client to get into a state
where it couldn't commit transactions.
https://bugs.launchpad.net/zodb/+bug/374737
- Fixed vulnerabilities in the ZEO network protocol that allow:
- CVE-2009-0668 Arbitrary Python code execution in ZODB ZEO storage servers
- CVE-2009-0669 Authentication bypass in ZODB ZEO storage servers
The vulnerabilities only apply if you are using ZEO to share a
database among multiple applications or application instances and if
untrusted clients are able to connect to your ZEO servers.
- Fixed the setup test command. It previously depended on private
functions in zope.testing.testrunner that don't exist any more.
- ZEO client threads were unnamed, making it hard to debug thread
management.
- ZEO protocol 2 support was broken. This caused very old clients to
be unable to use new servers.
- zeopack was less flexible than it was before. -h should default to
local host.
- The "lawn" layout was being selected by default if the root of
the blob directory happened to contain a hidden file or directory
such as ".svn". Now hidden files and directories are ignored
when choosing the default layout.
- BlobStorage was not compatible with MVCC storages because the
wrappers were being removed by each database connection. Fixed.
- Saving indexes for large file storages failed (with the error:
RuntimeError: maximum recursion depth exceeded). This can cause a
FileStorage to fail to start because it gets an error trying to save
its index.
- Sizes of new objects weren't added to the object cache size
estimation, causing the object-cache size limiting feature to let
the cache grow too large when many objects were added.
- Deleted records weren't removed when packing file storages.
- Fixed analyze.py and added test.
- fixed Python 2.6 compatibility issue with ZEO/zeoserverlog.py
- using hashlib.sha1 if available in order to avoid DeprecationWarning
under Python 2.6
- made runzeo -h work
- The monitor server didn't correctly report the actual number of
clients.
- Packing could return spurious errors due to errors notifying
disconnected clients of new database size statistics.
- Undo sometimes failed for FileStorages configured to support blobs.
- Starting ClientStorages sometimes failed with non-new but empty
cache files.
- The history method on ZEO clients failed.
- Fix for bug #251037: Make packing of blob storages non-blocking.
- Fix for bug #220856: Completed implementation of ZEO authentication.
- Fix for bug #184057: Make initialisation of small ZEO client file cache
sizes not fail.
- Fix for bug #184054: MappingStorage used to raise a KeyError during `load`
instead of a POSKeyError.
- Fixed bug in Connection.TmpStore: load() would not defer to the backend
storage for loading blobs.
- Fix for bug #181712: Make ClientStorage update `lastTransaction` directly
after connecting to a server, even when no cache verification is necessary.
- Fixed bug in blob filesystem helper: the `isSecure` check was inverted.
- Fixed bug in transaction buffer: a tuple was unpacked incorrectly in
`clear`.
- Bugfix the situation in which comparing persistent objects (for
instance, as members in BTree set or keys of BTree) might cause data
inconsistency during conflict resolution.
- Fixed bug 153316: persistent and BTrees were using `int`
for memory sizes which caused errors on x86_64 Intel Xeon machines
(using 64-bit Linux).
- Fixed small bug that the Connection.isReadOnly method didn't
work after a savepoint.
- Bug #98275: Made ZEO cache more tolerant when invalidating current
versions of objects.
- Fixed a serious bug that could cause client I/O to stop
(hang). This was accompanied by a critical log message along the
lines of: "RuntimeError: dictionary changed size during iteration".
- Fixed bug #127182: Blobs were subclassable which was not desired.
- Fixed bug #126007: tpc_abort had untested code path that was
broken.
- Fixed bug #129921: getSize() function in BlobStorage could not
deal with garbage files
- Fixed bug in which MVCC would not work for blobs.
- Fixed bug in ClientCache that occurred with objects larger than the total
cache size.
- When an error occured attempting to lock a file and logging of said error was
enabled.
- FileStorages previously saved indexes after a certain
number of writes. This was done during the last phase of two-phase
commit, which made this critical phase more subject to errors than
it should have been. Also, for large databases, saves were done so
infrequently as to be useless. The feature was removed to reduce
the chance for errors during the last phase of two-phase commit.
- File storages previously kept an internal object id to
transaction id mapping as an optimization. This mapping caused
excessive memory usage and failures during the last phase of
two-phase commit. This optimization has been removed.
- Refactored handling of invalidations on ZEO clients to fix
a possible ordering problem for invalidation messages.
- On many systems, it was impossible to create more than 32K
blobs. Added a new blob-directory layout to work around this
limitation.
- Fixed bug that could lead to memory errors due to the use
of a Python dictionary for a mapping that can grow large.
- Fixed bug #251037: Made packing of blob storages non-blocking.
- Fixed a bug that could cause InvalidObjectReference errors
for objects that were explicitly added to a database if the object
was modified after a savepoint that added the object.
- Fixed several bugs that caused ZEO cache corruption when connecting
to servers. These bugs affected both persistent and non-persistent caches.
- Improved the the ZEO client shutdown support to try to
avoid spurious errors on exit, especially for scripts, such as zeopack.
- Packing failed for databases containing cross-database references.
- Cross-database references to databases with empty names
weren't constructed properly.
- The zeo client cache used an excessive amount of memory, causing applications
with large caches to exhaust available memory.
- Fixed a number of bugs in the handling of persistent ZEO caches:
- Cache records are written in several steps. If a process exits
after writing begins and before it is finishes, the cache will be
corrupt on restart. The way records are written was changed to
make cache record updates atomic.
- There was no lock file to prevent opening a cache multiple times
at once, which would lead to corruption. Persistent caches now
use lock files, in the same way that file storages do.
- A bug in the cache-opening logic led to cache failure in the
unlikely event that a cache has no free blocks.
- When using ZEO Client Storages, Errors occured when trying to store
objects too big to fit in the ZEO cache file.
- Fixed bug in blob filesystem helper: the `isSecure` check was inverted.
- Fixed bug in transaction buffer: a tuple was unpacked incorrectly in
`clear`.
- Fixed bug in Connection.TmpStore: load() would not defer to the
back-end storage for loading blobs.
- Fixed bug #190884: Wrong reference to `POSKeyError` caused NameError.
- Completed implementation of ZEO authentication. This fixes issue 220856.
What's new in ZODB 3.8.0
========================
General
-------
- (unreleased) Fixed setup.py use of setuptools vs distutils, so .c and .h
files are included in the bdist_egg.
- The ZODB Storage APIs have been documented and cleaned up.
- ZODB versions are now officially deprecated and support for them
will be removed in ZODB 3.9. (They have been widely recognized as
deprecated for quite a while.)
- Changed the automatic garbage collection when opening a connection to only
apply the garbage collections on those connections in the pool that are
closed. (This fixed issue 113923.)
ZEO
---
- (3.8a1) ZEO's strategoes for avoiding client cache verification were
improved in the case that servers are restarted. Before, if
transactions were committed after the restart, clients that were up
to date or nearly up to date at the time of the restart and then
connected had to verify their caches. Now, it is far more likely
that a client that reconnects soon after a server restart won't have
to verify its cache.
- (3.8a1) Fixed a serious bug that could cause clients that disconnect from and
reconnect to a server to get bad invalidation data if the server
serves multiple storages with active writes.
- (3.8a1) It is now theoretically possible to use a ClientStorage in a storage
server. This might make it possible to offload read load from a
storage server at the cost of increasing write latency. This should
increase write throughput by offloading reads from the final storage
server. This feature is somewhat experimental. It has tests, but
hasn't been used in production.
Transactions
------------
- (3.8a1) Add a doom() and isDoomed() interface to the transaction module.
First step towards the resolution of
http://www.zope.org/Collectors/Zope3-dev/655
A doomed transaction behaves exactly the same way as an active transaction
but raises an error on any attempt to commit it, thus forcing an abort.
Doom is useful in places where abort is unsafe and an exception cannot be
raised. This occurs when the programmer wants the code following the doom to
run but not commit. It is unsafe to abort in these circumstances as a
following get() may implicitly open a new transaction.
Any attempt to commit a doomed transaction will raise a DoomedTransaction
exception.
- (3.8a1) Clean up the ZODB imports in transaction.
Clean up weird import dance with ZODB. This is unnecessary since the
transaction module stopped being imported in ZODB/__init__.py in rev 39622.
- (3.8a1) Support for subtransactions has been removed in favor of
save points.
Blobs
-----
- (3.8b1) Updated the Blob implementation in a number of ways. Some
of these are backward incompatible with 3.8a1:
o The Blob class now lives in ZODB.blob
o The blob openDetached method has been replaced by the committed method.
- (3.8a1) Added new blob feature. See the ZODB/Blobs directory for
documentation.
ZODB now handles (reasonably) large binary objects efficiently. Useful to
use from a few kilobytes to at least multiple hundred megabytes.
BTrees
------
- (3.8a1) Added support for 64-bit integer BTrees as separate types.
(For now, we're retaining compile-time support for making the regular
integer BTrees 64-bit.)
- (3.8a1) Normalize names in modules so that BTrees, Buckets, Sets, and
TreeSets can all be accessed with those names in the modules (e.g.,
BTrees.IOBTree.BTree). This is in addition to the older names (e.g.,
BTrees.IOBTree.IOBTree). This allows easier drop-in replacement, which
can especially be simplify code for packages that want to support both
32-bit and 64-bit BTrees.
- (3.8a1) Describe the interfaces for each module and actually declare
the interfaces for each.
- (3.8a1) Fix module references so klass.__module__ points to the Python
wrapper module, not the C extension.
- (3.8a1) introduce module families, to group all 32-bit and all 64-bit
modules.
What's new in ZODB3 3.7.0
==========================
Release date: 2007-04-20
Packaging
---------
- (3.7.0b3) ZODB is now packaged without it's dependencies
ZODB no longer includes copies of dependencies such as
ZConfig, zope.interface and so on. It now treats these as
dependencies. If ZODB is installed with easy_install or
zc.buildout, the dependencies will be installed automatically.
- (3.7.0b3) ZODB is now a buildout
ZODB checkouts are now built and tested using zc.buildout.
- (3.7b4) Added logic to avoid spurious errors from the logging system
on exit.
- (3.7b2) Removed the "sync" mode for ClientStorage.
Previously, a ClientStorage could be in either "sync" mode or "async"
mode. Now there is just "async" mode. There is now a dedicicated
asyncore main loop dedicated to ZEO clients.
Applications no-longer need to run an asyncore main loop to cause
client storages to run in async mode. Even if an application runs an
asyncore main loop, it is independent of the loop used by client
storages.
This addresses a test failure on Mac OS X,
http://www.zope.org/Collectors/Zope3-dev/650, that I believe was due
to a bug in sync mode. Some asyncore-based code was being called from
multiple threads that didn't expect to be.
Converting to always-async mode revealed some bugs that weren't caught
before because the tests ran in sync mode. These problems could
explain some problems we've seen at times with clients taking a long
time to reconnect after a disconnect.
Added a partial heart beat to try to detect lost connections that
aren't otherwise caught,
http://mail.zope.org/pipermail/zodb-dev/2005-June/008951.html, by
perioidically writing to all connections during periods of inactivity.
Connection management
---------------------
- (3.7a1) When more than ``pool_size`` connections have been closed,
``DB`` forgets the excess (over ``pool_size``) connections closed first.
Python's cyclic garbage collection can take "a long time" to reclaim them
(and may in fact never reclaim them if application code keeps strong
references to them), but such forgotten connections can never be opened
again, so their caches are now cleared at the time ``DB`` forgets them.
Most applications won't notice a difference, but applications that open
many connections, and/or store many large objects in connection caches,
and/or store limited resources (such as RDB connections) in connection
caches may benefit.
BTrees
------
- Support for 64-bit integer keys and values has been provided as a
compile-time option for the "I" BTrees (e.g. IIBTree).
Documentation
-------------
- (3.7a1) Thanks to Stephan Richter for converting many of the doctest
files to ReST format. These are now chapters in the Zope 3 apidoc too.
IPersistent
-----------
- (3.7a1) The documentation for ``_p_oid`` now specifies the concrete
type of oids (in short, an oid is either None or a non-empty string).
Testing
-------
- (3.7b2) Fixed test-runner output truncation.
A bug was fixed in the test runner that caused result summaries to be
omitted when running on Windows.
Tools
-----
- (3.7a1) The changeover from zLOG to the logging module means that some
tools need to perform minimal logging configuration themselves. Changed
the zeoup script to do so and thus enable it to emit error messages.
BTrees
------
- (3.7a1) Suppressed warnings about signedness of characters when
compiling under GCC 4.0.x. See http://www.zope.org/Collectors/Zope/2027.
Connection
----------
- (3.7a1) An optimization for loading non-current data (MVCC) was
inadvertently disabled in ``_setstate()``; this has been repaired.
persistent
----------
- (3.7a1) Suppressed warnings about signedness of characters when
compiling under GCC 4.0.x. See http://www.zope.org/Collectors/Zope/2027.
- (3.7a1) PersistentMapping was inadvertently pickling volatile attributes
(http://www.zope.org/Collectors/Zope/2052).
After Commit hooks
------------------
- (3.7a1) Transaction objects have a new method,
``addAfterCommitHook(hook, *args, **kws)``. Hook functions
registered with a transaction are called after the transaction
commits or aborts. For example, one might want to launch non
transactional or asynchrnonous code after a successful, or aborted,
commit. See ``test_afterCommitHook()`` in
``transaction/tests/test_transaction.py`` for a tutorial doctest,
and the ``ITransaction`` interface for details.
What's new in ZODB3 3.6.2?
==========================
Release date: 15-July-2006
DemoStorage
-----------
- (3.6.2) DemoStorage was unable to wrap base storages who did not have
an '_oid' attribute: most notably, ZEO.ClientStorage
(http://www.zope.org/Collectors/Zope/2016).
Following is combined news from internal releases (to support ongoing
Zope2 / Zope3 development). These are the dates of the internal releases:
- 3.6.1 27-Mar-2006
- 3.6.0 05-Jan-2006
- 3.6b6 01-Jan-2006
- 3.6b5 18-Dec-2005
- 3.6b4 04-Dec-2005
- 3.6b3 06-Nov-2005
- 3.6b2 25-Oct-2005
- 3.6b1 24-Oct-2005
- 3.6a4 07-Oct-2005
- 3.6a3 07-Sep-2005
- 3.6a2 06-Sep-2005
- 3.6a1 04-Sep-2005
Removal of Features Deprecated in ZODB 3.4
------------------------------------------
(3.6b2) ZODB 3.6 no longer contains features officially deprecated in the
ZODB 3.4 release. These include:
- ``get_transaction()``. Use ``transaction.get()`` instead.
``transaction.commit()`` is a shortcut spelling of
``transaction.get().commit()``, and ``transaction.abort()``
of ``transaction.get().abort()``. Note that importing ZODB no longer
installs ``get_transaction`` as a name in Python's ``__builtin__``
module either.
- The ``begin()`` method of ``Transaction`` objects. Use the ``begin()``
method of a transaction manager instead. ``transaction.begin()`` is
a shortcut spelling to call the default transaction manager's ``begin()``
method.
- The ``dt`` argument to ``Connection.cacheMinimize()``.
- The ``Connection.cacheFullSweep()`` method. Use ``cacheMinimize()``
instead.
- The ``Connection.getTransaction()`` method. Pass a transaction manager
to ``DB.open()`` instead.
- The ``Connection.getLocalTransaction()`` method. Pass a transaction
manager to ``DB.open()`` instead.
- The ``cache_deactivate_after`` and ``version_cache_deactivate_after``
arguments to the ``DB`` constructor.
- The ``temporary``, ``force``, and ``waitflag`` arguments
to ``DB.open()``. ``DB.open()`` no longer blocks (there's no longer
a fixed limit on the number of open connections).
- The ``transaction`` and ``txn_mgr``arguments to ``DB.open()``. Use
the ``transaction_manager`` argument instead.
- The ``getCacheDeactivateAfter``, ``setCacheDeactivateAfter``,
``getVersionCacheDeactivateAfter`` and ``setVersionCacheDeactivateAfter``
methods of ``DB``.
Persistent
----------
- (3.6.1) Suppressed warnings about signedness of characters when
compiling under GCC 4.0.x. See http://www.zope.org/Collectors/Zope/2027.
- (3.6a4) ZODB 3.6 introduces a change to the basic behavior of Persistent
objects in a particular end case. Before ZODB 3.6, setting
``obj._p_changed`` to a true value when ``obj`` was a ghost was ignored:
``obj`` remained a ghost, and getting ``obj._p_changed`` continued to
return ``None``. Starting with ZODB 3.6, ``obj`` is activated instead
(unghostified), and its state is changed from the ghost state to the
changed state. The new behavior is less surprising and more robust.
- (3.6b5) The documentation for ``_p_oid`` now specifies the concrete
type of oids (in short, an oid is either None or a non-empty string).
Commit hooks
------------
- (3.6a1) The ``beforeCommitHook()`` method has been replaced by the new
``addBeforeCommitHook()`` method, with a more-robust signature.
``beforeCommitHook()`` is now deprecated, and will be removed in ZODB 3.8.
Thanks to Julien Anguenot for contributing code and tests.
Connection management
---------------------
- (3.6b6) When more than ``pool_size`` connections have been closed,
``DB`` forgets the excess (over ``pool_size``) connections closed first.
Python's cyclic garbage collection can take "a long time" to reclaim them
(and may in fact never reclaim them if application code keeps strong
references to them), but such forgotten connections can never be opened
again, so their caches are now cleared at the time ``DB`` forgets them.
Most applications won't notice a difference, but applications that open
many connections, and/or store many large objects in connection caches,
and/or store limited resources (such as RDB connections) in connection
caches may benefit.
ZEO
---
- (3.6a4) Collector 1900. In some cases of pickle exceptions raised by
low-level ZEO communication code, callers of ``marshal.encode()`` could
attempt to catch an exception that didn't actually exist, leading to an
erroneous ``AttributeError`` exception. Thanks to Tres Seaver for the
diagnosis.
BaseStorage
-----------
- (3.6a4) Nothing done by ``tpc_abort()`` should raise an exception.
However, if something does (an error case), ``BaseStorage.tpc_abort()``
left the commit lock in the acquired state, causing any later attempt
to commit changes hang.
Multidatabase
-------------
- (3.6b1) The ``database_name`` for a database in a multidatabase
collection can now be specified in a config file's ```` section,
as the value of the optional new ``database_name`` key. The
``.databases`` attribute cannot be specified in a config file, but
can be passed as the optional new ``databases`` argument to the
``open()`` method of a ZConfig factory for type ``ZODBDatabase``.
For backward compatibility, Zope 2.9 continues to allow using the
name in its ```` config section as the database name
(note that ```` is defined by Zope, not by ZODB -- it's a
Zope-specific extension of ZODB's ```` section).
PersistentMapping
-----------------
- (3.6.1) PersistentMapping was inadvertently pickling volatile attributes
(http://www.zope.org/Collectors/Zope/2052).
- (3.6b4) ``PersistentMapping`` makes changes by a ``pop()`` method call
persistent now (http://www.zope.org/Collectors/Zope/2036).
- (3.6a1) The ``PersistentMapping`` class has an ``__iter__()`` method
now, so that objects of this type work well with Python's iteration
protocol. For example, if ``x`` is a ``PersistentMapping`` (or
Python dictionary, or BTree, or ``PersistentDict``, ...), then
``for key in x:`` iterates over the keys of ``x``, ``list(x)`` creates
a list containing ``x``'s keys, ``iter(x)`` creates an iterator for
``x``'s keys, and so on.
Tools
-----
- (3.6b5) The changeover from zLOG to the logging module means that some
tools need to perform minimal logging configuration themselves. Changed
the zeoup script to do so and thus enable it to emit error messages.
BTrees
------
- (3.6.1) Suppressed warnings about signedness of characters when
compiling under GCC 4.0.x. See http://www.zope.org/Collectors/Zope/2027.
- (3.6a1) BTrees and Buckets now implement the ``setdefault()`` and ``pop()``
methods. These are exactly like Python's dictionary methods of the same
names, except that ``setdefault()`` requires both arguments (and Python is
likely to change to require both arguments too -- defaulting the
``default`` argument to ``None`` has no viable use cases). Thanks to
Ruslan Spivak for contributing code, tests, and documentation.
- (3.6a1) Collector 1873. It wasn't possible to construct a BTree or Bucket
from, or apply their update() methods to, a PersistentMapping or
PersistentDict. This works now.
ZopeUndo
--------
- (3.6a4) Collector 1810. A previous bugfix (#1726) broke listing undoable
transactions for users defined in a non-root acl_users folder. Zope logs
a acl_users path together with a username (separated by a space) and this
previous fix failed to take this into account.
Connection
----------
- (3.6b5) An optimization for loading non-current data (MVCC) was
inadvertently disabled in ``_setstate()``; this has been repaired.
Documentation
-------------
- (3.6b3) Thanks to Stephan Richter for converting many of the doctest
files to ReST format. These are now chapters in the Zope 3 apidoc too.
- (3.6b4) Several misspellings of "occurred" were repaired.
Development
-----------
- (3.6a1) The source code for the old ExtensionClass-based Persistence
package moved, from ZODB to the Zope 2.9 development tree. ZODB 3.5
makes no use of Persistence, and, indeed, the Persistence package could
not be compiled from a ZODB release, since some of the C header files
needed appear only in Zope.
- (3.6a3) Re-added the ``zeoctl`` module, for the same reasons
``mkzeoinst`` was re-added (see below).
- (3.6a2) The ``mkzeoinst`` module was re-added to ZEO, because Zope3
has a script that expects to import it from there. ZODB's ``mkzeoinst``
script was rewritten to invoke the ``mkzeoinst`` module.
``transact``
------------
- (3.6b4) Collector 1959: The undocumented ``transact`` module no
longer worked. It remains undocumented and untested, but thanks to
Janko Hauser it's possible that it works again ;-).
What's new in ZODB3 3.5.1?
==========================
Release date: 26-Sep-2005
Following is combined news from internal releases (to support ongoing
Zope3 development). These are the dates of the internal releases:
- 3.5.1b2 07-Sep-2005
- 3.5.1b1 06-Sep-2005
Build
-----
- (3.5.1b2) Re-added the ``zeoctl`` module, for the same reasons
``mkzeoinst`` was re-added (see below).
- (3.5.1b1) The ``mkzeoinst`` module was re-added to ZEO, because Zope3
has a script that expects to import it from there. ZODB's ``mkzeoinst``
script was rewritten to invoke the ``mkzeoinst`` module.
ZopeUndo
--------
- (3.5.1) Collector 1810. A previous bugfix (#1726) broke listing undoable
transactions for users defined in a non-root acl_users folder. Zope logs
a acl_users path together with a username (separated by a space) and this
previous fix failed to take this into account.
What's new in ZODB3 3.5.0?
==========================
Release date: 31-Aug-2005
Following is combined news from internal releases (to support ongoing
Zope3 development). These are the dates of the internal releases:
- 3.5a7 11-Aug-2005
- 3.5a6 04-Aug-2005
- 3.5a5 19-Jul-2005
- 3.5a4 14-Jul-2005
- 3.5a3 17-Jun-2005
- 3.5a2 16-Jun-2005
- 3.5a1 10-Jun-2005
Savepoints
----------
- (3.5.0) As for deprecated subtransaction commits, the intent was
that making a savepoint would invoke incremental garbage collection on
Connection memory caches, to try to reduce the number of objects in
cache to the configured cache size. Due to an oversight, this didn't
happen, and stopped happening for subtransaction commits too. Making a
savepoint (or doing a subtransaction commit) does invoke cache gc now.
- (3.5a3) When a savepoint is made, the states of objects modified so far
are saved to a temporary storage (an instance of class ``TmpStore``,
although that's an internal implementation detail). That storage needs
to implement the full storage API too, but was missing the ``loadBefore()``
method needed for MVCC to retrieve non-current revisions of objects. This
could cause spurious errors if a transaction with a pending savepoint
needed to fetch an older revision of some object.
- (3.5a4) The ``ISavepoint`` interface docs said you could roll back to a
given savepoint any number of times (until the transaction ends, or until
you roll back to an earlier savepoint's state), but the implementation
marked a savepoint as invalid after its first use. The implementation has
been repaired, to match the docs.
ZEO client cache
----------------
- (3.5a6) Two memory leaks in the ZEO client cache were repaired, a
major one involving ``ZEO.cache.Entry`` objects, and a minor one involving
empty lists.
Subtransactions are deprecated
------------------------------
- (3.5a4) Subtransactions are deprecated, and will be removed in ZODB 3.7.
Use savepoints instead. Savepoints are more powerful, and code using
subtransactions does not mix well with code using savepoints (a
subtransaction commit forces all current savepoints to become unusable, so
code using subtransactions can hurt newer code trying to use savepoints).
In general, a subtransaction commit done just to free memory can be changed
from::
transaction.commit(1)
to::
transaction.savepoint(True)
That is, make a savepoint, and forget it. As shown, it's best to pass
``True`` for the optional ``optimistic`` argument in this case: because
there's no possibility of asking for a rollback later, there's no need
to insist that all data managers support rollback.
In rarer cases, a subtransaction commit is followed later by a
subtransaction abort. In that case, change the initial::
transaction.commit(1)
to::
sp = transaction.savepoint()
and in place of the subtransaction abort::
transaction.abort(1)
roll back the savepoint instead::
sp.rollback()
- (3.5a4) Internal uses of subtransactions (transaction ``commit()`` or
``abort()`` passing a true argument) were rewritten to use savepoints
instead.
Multi-database
--------------
- (3.5a1) Preliminary support for persistent cross-database references has
been added. See ``ZODB/cross-database-references.txt`` for an
introduction.
Tools
-----
- (3.5a6, 3.5a7) Collector #1847. The ZEO client cache tracing and simulation
tools weren't updated to work with ZODB 3.3, and the introduction of
MVCC required major reworking of the tracing and simulation code. These
tools are in a working state again, although so far lightly tested on
just a few applications. In ``doc/ZEO/``, see the heavily revised
``trace.txt`` and ``cache.txt``.
- (3.5a5) Collector #1846: If an uncommitted transaction was found,
fsrecover.py fell into an infinite loop.
Windows
-------
- (3.5a6) As developed in a long thread starting at
http://mail.zope.org/pipermail/zope/2005-July/160433.html
there appears to be a race bug in the Microsoft Windows socket
implementation, rarely visible in ZEO when multiple processes try to
create an "asyncore trigger" simultaneously. Windows-specific code in
``ZEO/zrpc/trigger.py`` changed to work around this bug when it occurs.
ThreadedAsync.LoopCallback
--------------------------
- (3.5a5) This once again physically replaces Python's ``asyncore.loop``
function with its own loop function, because it turns out Zope relied on
the seemingly unused ``LoopCallback.exit_status`` global, which was
removed in the change described below. Python's ``asyncore.loop`` is again
not invoked, so any breakpoints or debugging prints added to that are again
"lost".
- (3.5a4) This replaces Python's ``asyncore.loop`` function with its own, in
order to get notified when ``loop()`` is first called. The signature of
``asyncore.loop`` changed in Python 2.4, but ``LoopCallback.loop``'s
signature didn't change to match. The code here was repaired to be
compatible with both old and new signatures, and also repaired to invoke
Python's ``asyncore.loop()`` instead of replacing it entirely (so, for
example, debugging prints added to Python's ``asyncore.loop`` won't be
lost anymore).
FileStorage
-----------
- (3.5a4) Collector #1830. In some error cases when reading a FileStorage
index, the code referenced an undefined global.
- (3.5a4) Collector #1822. The ``undoLog()`` and ``undoInfo()`` methods
were changed in 3.4a9 to return the documented results. Alas, some pieces
of (non-ZODB) code relied on the actual behavior. When the ``first`` and
``last`` arguments are both >= 0, these methods now treat them as if they
were Python slice indices, including the `first` index but excluding the
``last`` index. This matches former behavior, although it contradicts older
ZODB UML documentation. The documentation in
``ZODB.interfaces.IStorageUndoable`` was changed to match the new intent.
- (3.5a2) The ``_readnext()`` method now returns the transaction size as
the value of the "size" key. Thanks to Dieter Maurer for the patch, from
http://mail.zope.org/pipermail/zodb-dev/2003-October/006157.html. "This is
very valuable when you want to spot strange transaction sizes via Zope's
'Undo' tab".
BTrees
------
- (3.5.a5) Collector 1843. When a non-integer was passed to a method like
``keys()`` of a Bucket or Set with integer keys, an internal error code
was overlooked, leading to everything from "delayed errors" to segfaults.
Such cases raise TypeError now, as intended.
- (3.5a4) Collector 1831. The BTree ``minKey()`` and ``maxKey()`` methods
gave a misleading message if no key satisfying the constraints existed in a
non-empty tree.
- (3.5a4) Collector 1829. Clarified that the ``minKey()`` and ``maxKey()``
methods raise an exception if no key exists satsifying the constraints.
- (3.5a4) The ancient ``convert.py`` script was removed. It was intended to
convert "old" BTrees to "new" BTrees, but the "old" BTree implementation
was removed from ZODB years ago.
What's new in ZODB3 3.4.1?
==========================
Release date: 09-Aug-2005
Following are dates of internal releases (to support ongoing Zope 2
development) since ZODB 3.4's last public release:
- 3.4.1b5 08-Aug-2005
- 3.4.1b4 07-Aug-2005
- 3.4.1b3 04-Aug-2005
- 3.4.1b2 02-Aug-2005
- 3.4.1b1 26-Jul-2005
- 3.4.1a6 19-Jul-2005
- 3.4.1a5 12-Jul-2005
- 3.4.1a4 08-Jul-2005
- 3.4.1a3 02-Jul-2005
- 3.4.1a2 29-Jun-2005
- 3.4.1a1 27-Jun-2005
Savepoints
----------
- (3.4.1a1) When a savepoint is made, the states of objects modified so far
are saved to a temporary storage (an instance of class ``TmpStore``,
although that's an internal implementation detail). That storage needs
to implement the full storage API too, but was missing the ``loadBefore()``
method needed for MVCC to retrieve non-current revisions of objects. This
could cause spurious errors if a transaction with a pending savepoint
needed to fetch an older revision of some object.
- (3.4.1a5) The ``ISavepoint`` interface docs said you could roll back to a
given savepoint any number of times (until the transaction ends, or until
you roll back to an earlier savepoint's state), but the implementation
marked a savepoint as invalid after its first use. The implementation has
been repaired, to match the docs.
- (3.4.1b4) Collector 1860: use an optimistic savepoint in ExportImport
(there's no possiblity of rollback here, so no need to insist that the
data manager support rollbacks).
ZEO client cache
----------------
- (3.4.1b3) Two memory leaks in the ZEO client cache were repaired, a
major one involving ``ZEO.cache.Entry`` objects, and a minor one involving
empty lists.
Subtransactions
---------------
- (3.4.1a5) Internal uses of subtransactions (transaction ``commit()`` or
``abort()`` passing a true argument) were rewritten to use savepoints
instead. Application code is strongly encouraged to do this too:
subtransactions are weaker, will be deprecated soon, and do not mix well
with savepoints (when you do a subtransaction commit, all current
savepoints are made unusable). In general, a subtransaction commit
done just to free memory can be changed from::
transaction.commit(1)
to::
transaction.savepoint(True)
That is, make a savepoint, and forget it. As shown, it's best to pass
``True`` for the optional ``optimistic`` argument in this case: because
there's no possibility of asking for a rollback later, there's no need
to insist that all data managers support rollback.
In rarer cases, a subtransaction commit is followed later by a
subtransaction abort. In that case, change the initial::
transaction.commit(1)
to::
sp = transaction.savepoint()
and in place of the subtransaction abort::
transaction.abort(1)
roll back the savepoint instead::
sp.rollback()
FileStorage
-----------
- (3.4.1a3) Collector #1830. In some error cases when reading a FileStorage
index, the code referenced an undefined global.
- (3.4.1a2) Collector #1822. The ``undoLog()`` and ``undoInfo()`` methods
were changed in 3.4a9 to return the documented results. Alas, some pieces
of (non-ZODB) code relied on the actual behavior. When the `first` and
`last` arguments are both >= 0, these methods now treat them as if they
were Python slice indices, including the `first` index but excluding the
`last` index. This matches former behavior, although it contradicts older
ZODB UML documentation. The documentation in
``ZODB.interfaces.IStorageUndoable`` was changed to match the new intent.
- (3.4.1a1) The ``UndoSearch._readnext()`` method now returns the transaction
size as the value of the "size" key. Thanks to Dieter Maurer for the
patch, from
http://mail.zope.org/pipermail/zodb-dev/2003-October/006157.html. "This is
very valuable when you want to spot strange transaction sizes via Zope's
'Undo' tab".
ThreadedAsync.LoopCallback
--------------------------
- (3.4.1a6) This once again physically replaces Python's ``asyncore.loop``
function with its own loop function, because it turns out Zope relied on
the seemingly unused ``LoopCallback.exit_status`` global, which was
removed in the change described below. Python's ``asyncore.loop`` is again
not invoked, so any breakpoints or debugging prints added to that are again
"lost".
- (3.4.1a1) This replaces Python's ``asyncore.loop`` function with its own,
in order to get notified when ``loop()`` is first called. The signature of
``asyncore.loop`` changed in Python 2.4, but ``LoopCallback.loop``'s
signature didn't change to match. The code here was repaired to be
compatible with both old and new signatures, and also repaired to invoke
Python's ``asyncore.loop()`` instead of replacing it entirely (so, for
example, debugging prints added to Python's ``asyncore.loop`` won't be lost
anymore).
Windows
-------
- (3.4.1b2) As developed in a long thread starting at
http://mail.zope.org/pipermail/zope/2005-July/160433.html
there appears to be a race bug in the Microsoft Windows socket
implementation, rarely visible in ZEO when multiple processes try to
create an "asyncore trigger" simultaneously. Windows-specific code in
``ZEO/zrpc/trigger.py`` changed to work around this bug when it occurs.
Tools
-----
- (3.4.1b1 thru 3.4.1b5) Collector #1847. The ZEO client cache tracing and
simulation tools weren't updated to work with ZODB 3.3, and the
introduction of MVCC required major reworking of the tracing and simulation
code. These tools are in a working state again, although so far lightly
tested on just a few applications. In ``doc/ZEO/``, see the heavily revised
``trace.txt`` and ``cache.txt``.
- (3.4.1a6) Collector #1846: If an uncommitted transaction was found,
fsrecover.py fell into an infinite loop.
DemoStorage
-----------
- (3.4.1a1) The implementation of ``undoLog()`` was wrong in several ways;
repaired.
BTrees
------
- (3.4.1a6) Collector 1843. When a non-integer was passed to a method like
``keys()`` of a Bucket or Set with integer keys, an internal error code
was overlooked, leading to everything from "delayed errors" to segfaults.
Such cases raise TypeError now, as intended.
- (3.4.1a4) Collector 1831. The BTree ``minKey()`` and ``maxKey()`` methods
gave a misleading message if no key satisfying the constraints existed in a
non-empty tree.
- (3.4.1a3) Collector 1829. Clarified that the ``minKey()`` and ``maxKey()``
methods raise an exception if no key exists satsifying the constraints.
What's new in ZODB3 3.4?
========================
Release date: 09-Jun-2005
Following is combined news from the "internal releases" (to support
ongoing Zope 2.8 and Zope3 development) since the last public ZODB 3.4
release. These are the dates of the internal releases:
- 3.4c2 06-Jun-2005
- 3.4c1 03-Jun-2005
- 3.4b3 27-May-2005
- 3.4b2 26-May-2005
Connection, DB
--------------
- (3.4b3) ``.transaction_manager`` is now a public attribute of
IDataManager, and is the instance of ITransactionManager used by the
data manager as its transaction manager. There was previously no way
to ask a data manager which transaction manager it was using. It's
intended that ``transaction_manager`` be treated as read-only.
- (3.4b3) For sanity, the ``txn_mgr`` argument to ``DB.open()``,
``Connection.__init__()``, and ``Connection._setDB()`` has been renamed
to ``transaction_manager``. ``txn_mgr`` is still accepted, but is
deprecated and will be removed in ZODB 3.6. Any code that was using
the private ``._txn_mgr`` attribute of ``Connection`` will break
immediately.
Development
-----------
- (3.4b2) ZODB's ``test.py`` is now a small driver for the shared
``zope.testing.testrunner``. See the latter's documentation
for command-line arguments.
Error reporting
---------------
- (3.4c1) In the unlikely event that ``referencesf()`` reports an unpickling
error (for example, a corrupt database can cause this), the message it
produces no longer contains unprintable characters.
Tests
-----
- (3.4c2) ``checkCrossDBInvalidations`` suffered spurious failures too often
on slow and/or busy machines. The test is willing to wait longer for
success now.
What's new in ZODB3 3.4b1?
==========================
Release date: 19-May-2005
What follows is combined news from the "internal releases" (to support
ongoing Zope 2.8 and Zope3 development) since the last public ZODB 3.4
release. These are the dates of the internal releases:
- 3.4b1 19-May-2005
- 3.4a9 12-May-2005
- 3.4a8 09-May-2005
- 3.4a7 06-May-2005
- 3.4a6 05-May-2005
- 3.4a5 25-Apr-2005
- 3.4a4 23-Apr-2005
- 3.4a3 13-Apr-2005
- 3.4a2 03-Apr-2005
transaction
-----------
- (3.4a7) If the first activity seen by a new ``ThreadTransactionManager`` was
an explicit ``begin()`` call, then synchronizers registered after that (but
still during the first transaction) were not communicated to the
transaction object. As a result, the ``afterCompletion()`` methods of
registered synchronizers weren't called when the first transaction ended.
- (3.4a6) Doing a subtransaction commit erroneously processed invalidations,
which could lead to an inconsistent view of the database. For example, let
T be the transaction of which the subtransaction commit was a part. If T
read a persistent object O's state before the subtransaction commit, did not
commit new state of its own for O during its subtransaction commit, and O
was modified before the subtransaction commit by a different transaction,
then the subtransaction commit processed an invalidation for O, and the
state T read for O originally was discarded in T. If T went on to access O
again, it saw the newly committed (by a different transaction) state for O::
o_attr = O.some_attribute
get_transaction().commit(True)
assert o_attr == O.some_attribute
could fail, and despite that T never modifed O.
- (3.4a4) Transactions now support savepoints. Savepoints allow changes to be
periodically checkpointed within a transaction. You can then rollback to a
previously created savepoint. See ``transaction/savepoint.txt``.
- (3.4a6) A ``getBeforeCommitHooks()`` method was added. It returns an
iterable producing the registered beforeCommit hooks.
- (3.4a6) The ``ISynchronizer`` interface has a new ``newTransaction()``
method. This is invoked whenever a transaction manager's ``begin()`` method
is called. (Note that a transaction object's (as opposed to a transaction
manager's) ``begin()`` method is deprecated, and ``newTransaction()`` is
not called when using the deprecated method.)
- (3.4a6) Relatedly, ``Connection`` implements ``ISynchronizer``, and
``Connection``'s ``afterCompletion()`` and ``newTransaction()`` methods now
call ``sync()`` on the underlying storage (if the underlying storage has
such a method), in addition to processing invalidations. The practical
implication is that storage synchronization will be done automatically now,
whenever a transaction is explicitly started, and after top-level
transaction commit or abort. As a result, ``Connection.sync()`` should
virtually never be needed anymore, and will eventually be deprecated.
- (3.4a3) Transaction objects have a new method, ``beforeCommitHook(hook,
*args, **kws)``. Hook functions registered with a transaction are called
at the start of a top-level commit, before any of the work is begun, so a
hook function can perform any database operations it likes. See
``test_beforeCommitHook()`` in ``transaction/tests/test_transaction.py``
for a tutorial doctest, and the ``ITransaction`` interface for details.
Thanks to Florent Guillaume for contributing code and tests.
- (3.4a3) Clarifications were made to transaction interfaces.
Support for ZODB4 savepoint-aware data managers has been dropped
----------------------------------------------------------------
- (3.4a4) In adding savepoint support, we dropped the attempted support for
ZODB4 data managers that support savepoints. We don't think that this will
affect anyone.
ZEO
---
- (3.4a4) The ZODB and ZEO version numbers are now the same. Concretely::
import ZODB, ZEO
assert ZODB.__version__ == ZEO.version
no longer fails. If interested, see the README file for details about
earlier version numbering schemes.
- (3.4b1) ZConfig version 2.3 adds new socket address types, for smoother
default behavior across platforms. The hostname portion of
socket-binding-address defaults to an empty string, which acts like
INADDR_ANY on Windows and Linux (bind to any interface). The hostname
portion of socket-connection-address defaults to "127.0.0.1" (aka
"localhost"). In config files, the types of ``zeo`` section keys
``address`` and ``monitor-address`` changed to socket-binding-address,
and the type of the ``zeoclient`` section key ``server`` changed to
socket-connection-address.
- (3.4a4) The default logging setup in ``runzeo.py`` was broken. It was
changed so that running ``runzeo.py`` from a command line now, and without
using a config file, prints output to the console much as ZODB 3.2 did.
ZEO on Windows
--------------
Thanks to Mark Hammond for these ``runzeo.py`` enhancements on Windows:
- (3.4b1) Collector 1788: Repair one of the new features below.
- (3.4a4) A pid file (containing the process id as a decimal string) is
created now for a ZEO server started via ``runzeo.py``. External programs
can read the pid from this file and derive a "signal name" used in a new
signal-emulation scheme for Windows. This is only necessary on Windows,
but the pid file is created on all platforms that implement
``os.getpid()``, as long as the ``pid-filename`` option is set, or
environment variable ``INSTANCE_HOME`` is defined. The ``pid-filename``
option can be set in a ZEO config file, or passed as the new ``--pid-file``
argument to ``runzeo.py``.
- (3.4a4) If available, ``runzeo.py`` now uses Zope's new 'Signal' mechanism
for Windows, to implement clean shutdown and log rotation handlers for
Windows. Note that the Python in use on the ZEO server must also have the
Python Win32 extensions installed for this to be useful.
Tools
-----
- (3.4a4) ``fsdump.py`` now displays the size (in bytes) of data records.
This actually went in several months go, but wasn't noted here at the time.
Thanks to Dmitry Vasiliev for contributing code and tests.
FileStorage
-----------
- (3.4a9) The ``undoLog()`` and ``undoInfo()`` methods almost always returned
a wrong number of results, one too many if ``last < 0`` (the default is
such a case), or one too few if ``last >= 0``. These have been repaired,
new tests were added, and these methods are now documented in
``ZODB.interfaces.IStorageUndoable``.
- (3.4a2) A ``pdb.set_trace()`` call was mistakenly left in method
``FileStorage.modifiedInVersion()``.
ZConfig
-------
- (3.4b1) The "standalone" release of ZODB now includes ZConfig version 2.3.
DemoStorage
-----------
- (3.4a4) Appropriate implementations of the storage API's ``registerDB()``
and ``new_oid()`` methods were added, delegating to the base storage. This
was needed to support wrapping a ZEO client storage as a ``DemoStorage``
base storage, as some new Zope tests want to do.
BaseStorage
-----------
- (3.4a4) ``new_oid()``'s undocumented ``last=`` argument was removed. It
was used only for internal recursion, and injured code sanity elsewhere
because not all storages included it in their ``new_oid()``'s signature.
Straightening this out required adding ``last=`` everywhere, or removing it
everywhere. Since recursion isn't actually needed, and there was no other
use for ``last=``, removing it everywhere was the obvious choice.
Tests
-----
- (3.4a3) The various flavors of the ``check2ZODBThreads`` and
``check7ZODBThreads`` tests are much less likely to suffer sproadic
failures now.
- (3.4a2) The test ``checkOldStyleRoot`` failed in Zope3, because of an
obscure dependence on the ``Persistence`` package (which Zope3 doesn't use).
ZApplication
------------
- (3.4a8) The file ``ZApplication.py`` was moved, from ZODB to Zope(2). ZODB
and Zope3 don't use it, but Zope2 does.
- (3.4a7) The ``__call__`` method didn't work if a non-None ``connection``
string argument was passed. Thanks to Stefan Holek for noticing.
What's new in ZODB3 3.4a1?
==========================
Release date: 01-Apr-2005
transaction
-----------
- ``get_transaction()`` is officially deprecated now, and will be removed
in ZODB 3.6. Use the ``transaction`` package instead. For example,
instead of::
import ZODB
...
get_transaction().commit()
do::
import transaction
...
transaction.commit()
DB
--
- There is no longer a hard limit on the number of connections that
``DB.open()`` will create. In other words, ``DB.open()`` never blocks
anymore waiting for an earlier connection to close, and ``DB.open()``
always returns a connection now (while it wasn't documented, it was
possible for ``DB.open()`` to return ``None`` before).
``pool_size`` continues to default to 7, but its meaning has changed:
if more than ``pool_size`` connections are obtained from ``DB.open()``
and not closed, a warning is logged; if more than twice ``pool_size``, a
critical problem is logged. ``pool_size`` should be set to the maximum
number of connections from the ``DB`` instance you expect to have open
simultaneously.
In addition, if a connection obtained from ``DB.open()`` becomes
unreachable without having been explicitly closed, when Python's garbage
collection reclaims that connection it no longer counts against the
``pool_size`` thresholds for logging messages.
The following optional arguments to ``DB.open()`` are deprecated:
``transaction``, ``waitflag``, ``force`` and ``temporary``. If one
is specified, its value is ignored, and ``DeprecationWarning`` is
raised. In ZODB 3.6, these optional arguments will be removed.
- Lightweight support for "multi-databases" is implemented. These are
collections of named DB objects and associated open Connections, such
that the Connection for any DB in the collection can be obtained from
a Connection from any other DB in the collection. See the new test
file ZODB/tests/multidb.txt for a tutorial doctest. Thanks to Christian
Theune for his work on this during the PyCon 2005 ZODB sprint.
ZEO compatibility
-----------------
There are severe restrictions on using ZEO servers and clients at or after
ZODB 3.3 with ZEO servers and clients from ZODB versions before 3.3. See the
reworked ``Compatibility`` section in ``README.txt`` for details. If
possible, it will be easiest to move clients and servers to 3.3+
simultaneously. With care, it's possible to use a 3.3+ ZEO server with
pre-3.3 ZEO clients, but not possible to use a pre-3.3 ZEO server with 3.3+
ZEO clients.
BTrees
------
- A new family of BTree types, in the ``IFBTree`` module, map
signed integers (32 bits) to C floats (also 32 bits). The
intended use is to help construct search indices, where, e.g.,
integer word or document identifiers map to scores of some
kind. This is easier than trying to work with scaled integer
scores in an ``IIBTree``, and Zope3 has moved to ``IFBTrees``
for these purposes in its search code.
FileStorage
-----------
- Addded a record iteration protocol to FileStorage. You can use the
record iterator to iterate over all current revisions of data
pickles in the storage.
In order to support calling via ZEO, we don't implement this as an
actual iterator. An example of using the record iterator protocol
is as follows::
storage = FileStorage('anexisting.fs')
next_oid = None
while True:
oid, tid, data, next_oid = storage.record_iternext(next_oid)
# do something with oid, tid and data
if next_oid is None:
break
The behavior of the iteration protocol is now to iterate over all
current records in the database in ascending oid order, although
this is not a promise to do so in the future.
Tools
-----
New tool fsoids.py, for heavy debugging of FileStorages; shows all
uses of specified oids in the entire database (e.g., suppose oid 0x345620
is missing -- did it ever exist? if so, when? who referenced it? when
was the last transaction that modified an object that referenced it?
which objects did it reference? what kind of object was it?).
ZODB/test/testfsoids.py is a tutorial doctest.
fsIndex
-------
Efficient, general implementations of ``minKey()`` and ``maxKey()`` methods
were added. ``fsIndex`` is a special hybrid kind of BTree used to implement
FileStorage indices. Thanks to Chris McDonough for code and tests.
What's new in ZODB3 3.3.1?
==========================
Release date: DD-MMM-2005
Tests
-----
The various flavors of the ``check2ZODBThreads`` and ``check7ZODBThreads``
tests are much less likely to suffer sproadic failures now.
What's new in ZODB3 3.3.1c1?
============================
Release date: 01-Apr-2005
BTrees
------
Collector #1734: BTrees conflict resolution leads to index inconsistencies.
Silent data loss could occur due to BTree conflict resolution when one
transaction T1 added a new key to a BTree containing at least three buckets,
and a concurrent transaction T2 deleted all keys in the bucket to which the
new key was added. Conflict resolution then created a bucket containing the
newly added key, but the bucket remained isolated, disconnected from the
BTree. In other words, the committed BTree didn't contain the new key added by
T1. Conflict resolution doesn't have enough information to repair this,
so ``ConflictError`` is now raised in such cases.
ZEO
---
Repaired subtle race conditions in establishing ZEO connections, both client-
and server-side. These account for intermittent cases where ZEO failed
to make a connection (or reconnection), accompanied by a log message showing
an error caught in ``asyncore`` and having a traceback ending with:
``UnpicklingError: invalid load key, 'Z'.``
or:
``ZRPCError: bad handshake '(K\x00K\x00U\x0fgetAuthProtocol)t.'``
or:
``error: (9, 'Bad file descriptor')``
or an ``AttributeError``.
These were exacerbated when running the test suite, because of an unintended
busy loop in the test scaffolding, which could starve the thread trying to
make a connection. The ZEO reconnection tests may run much faster now,
depending on platform, and should suffer far fewer (if any) intermittent
"timed out waiting for storage to connect" failures.
ZEO protocol and compatibility
------------------------------
ZODB 3.3 introduced multiversion concurrency control (MVCC), which required
changes to the ZEO protocol. The first 3.3 release should have increased
the internal ZEO protocol version number (used by ZEO protocol negotiation
when a client connects), but neglected to. This has been repaired.
Compatibility between pre-3.3 and post-3.3 ZEO clients and servers remains
very limited. See the newly updated ``Compatibility`` section in
``README.txt`` for details.
FileStorage
-----------
- The ``.store()`` and ``.restore()`` methods didn't update the storage's
belief about the largest oid in use when passed an oid larger than the
largest oid the storage already knew about. Because ``.restore()`` in
particular is used by ``copyTransactionsFrom()``, and by the first stage
of ZRS recovery, a large database could be created that believed the only
oid in use was oid 0 (the special oid reserved for the root object). In
rare cases, it could go on from there assigning duplicate oids to new
objects, starting over from oid 1 again. This has been repaired. A
new ``set_max_oid()`` method was added to the ``BaseStorage`` class so
that derived storages can update the largest oid in use in a threadsafe
way.
- A FileStorage's index file tried to maintain the index's largest oid as a
separate piece of data, incrementally updated over the storage's lifetime.
This scheme was more complicated than necessary, so was also more brittle
and slower than necessary. It indirectly participated in a rare but
critical bug: when a FileStorage was created via
``copyTransactionsFrom()``, the "maximum oid" saved in the index file was
always 0. Use that FileStorage, and it could then create "new" oids
starting over at 0 again, despite that those oids were already in use by
old objects in the database. Packing a FileStorage has no reason to
try to update the maximum oid in the index file either, so this kind of
damage could (and did) persist even across packing.
The index file's maximum-oid data is ignored now, but is still written
out so that ``.index`` files can be read by older versions of ZODB.
Finding the true maximum oid is done now by exploiting that the main
index is really a kind of BTree (long ago, this wasn't true), and finding
the largest key in a BTree is inexpensive.
- A FileStorage's index file could be updated on disk even if the storage
was opened in read-only mode. That bug has been repaired.
- An efficient ``maxKey()`` implementation was added to class ``fsIndex``.
Pickle (in-memory Connection) Cache
-----------------------------------
You probably never saw this exception:
``ValueError: Can not re-register object under a different oid``
It's been changed to say what it meant:
``ValueError: A different object already has the same oid``
This happens if an attempt is made to add distinct objects to the cache
that have the same oid (object identifier). ZODB should never do this,
but it's possible for application code to force such an attempt.
PersistentMapping and PersistentList
------------------------------------
Backward compatibility code has been added so that the sanest of the
ZODB 3.2 dotted paths for ``PersistentMapping`` and ``PersistentList``
resolve. These are still preferred:
- ``from persistent.list import PersistentList``
- ``from persistent.mapping import PersistentMapping``
but these work again too:
- ``from ZODB.PersistentList import PersistentList``
- ``from ZODB.PersistentMapping import PersistentMapping``
BTrees
------
The BTrees interface file neglected to document the optional
``excludemin`` and ``excludemax`` arguments to the ``keys()``, ``values()``
and ``items()`` methods. Appropriate changes were merged in from the
ZODB4 BTrees interface file.
Tools
-----
- ``mkzeoinst.py``'s default port number changed from to 9999 to 8100, to
match the example in Zope's ``zope.conf``.
fsIndex
-------
An efficient ``maxKey()`` method was implemented for the ``fsIndex`` class.
This makes it possible to determine the largest oid in a ``FileStorage``
index efficiently, directly, and reliably, replacing a more delicate scheme
that tried to keep track of this by saving an oid high water mark in the
index file and incrementally updating it.
What's new in ZODB3 3.3.1a1?
============================
Release date: 11-Jan-2005
ZEO client cache
----------------
- Collector 1536: The ``cache-size`` configuration option for ZEO clients
was being ignored. Worse, the client cache size was only one megabyte,
much smaller than the advertised default of 20MB. Note that the default
is carried over from a time when gigabyte disks were expensive and rare;
20MB is also too small on most modern machines.
- Fixed a nasty bug in cache verification. A persistent ZEO cache uses a
disk file, and, when active, has some in-memory data structures too to
speed operation. Invalidations processed as part of startup cache
verification were reflected in the in-memory data structures, but not
correctly in the disk file. So if an object revision was invalidated as
part of verification, the object wasn't loaded again before the connection
was closed, and the object revision remained in the cache file until the
connection was closed, then the next time the cache file was opened it
could believe that the stale object revision in the file was actually
current.
- Fixed a bug wherein an object removed from the client cache didn't
properly mark the file slice it occupied as being available for reuse.
ZEO
---
Collector 1503: excessive logging. It was possible for a ZEO client to
log "waiting for cache verification to finish" messages at a very high
rate, producing gigabytes of such messages in short order.
``ClientStorage._wait_sync()`` was changed to log no more than one
such message per 5 minutes.
persistent
----------
Collector #1350: ZODB has a default one-thread-per-connection model, and
two threads should never do operations on a single connection
simultaneously. However, ZODB can't detect violations, and this happened
in an early stage of Zope 2.8 development. The low-level ``ghostify()``
and ``unghostify()`` routines in ``cPerisistence.c`` were changed to give
some help in detecting this when it happens. In a debug build, both abort
the process if thread interference is detected. This is extreme, but
impossible to overlook. In a release build, ``unghostify()`` raises
``SystemError`` if thread damage is detected; ``ghostify()`` ignores the
problem in a release build (``ghostify()`` is supposed to be so simple that
it "can't fail").
ConflictError
-------------
New in 3.3, a ``ConflictError`` exception may attempt to insert the path to
the object's class in its message. However, a ZEO server may not have
access to application class implementations, and then the attempt by the
server to raise ``ConflictError`` could raise ``ImportError`` instead while
trying to determine the object's class path. This was confusing. The code
has been changed to obtain the class path from the object's pickle, without
trying to import application modules or classes.
FileStorage
-----------
Collector 1581: When an attempt to pack a corrupted ``Data.fs`` file was
made, it was possible for the pack routine to die with a reference to an
undefined global while it was trying to raise ``CorruptedError``. It
raises ``CorruptedError``, as it always intended, in these cases now.
Install
-------
The C header file ``ring.h`` is now installed.
Tools
-----
- ``BTrees.check.display()`` now displays the oids (if any) of the
BTree's or TreeSet's constituent objects.
What's new in ZODB3 3.3?
========================
Release date: 06-Oct-2004
ZEO
---
The encoding of RPC calls between server and client was being done
with protocol 0 ("text mode") pickles, which could require sending
four times as many bytes as necessary. Protocol 1 pickles are used
now. Thanks to Andreas Jung for the diagnosis and cure.
ZODB/component.xml
------------------
``cache-size`` parameters were changed from type ``integer`` to
type ``byte-size``. This allows you to specify, for example,
"``cache-size 20MB``" to get a 20 megabyte cache.
transaction
-----------
The deprecation warning for ``Transaction.begin()`` was changed to
point to the caller, instead of to ``Transaction.begin()`` itself.
Connection
----------
Restored Connection's private ``_opened`` attribute. This was still
referenced by ``DB.connectionDebugInfo()``, and Zope 2 calls the latter.
FileStorage
-----------
Collector #1517: History tab for ZPT does not work. ``FileStorage.history()``
was reading the user, description, and extension fields out of the object
pickle, due to starting the read at a wrong location. Looked like
cut-and-paste repetition of the same bug in ``FileStorage.FileIterator``
noted in the news for 3.3c1.
What's new in ZODB3 3.3 release candidate 1?
============================================
Release date: 14-Sep-2004
Connection
----------
ZODB intends to raise ``ConnnectionStateError`` if an attempt is made to
close a connection while modifications are pending (the connection is
involved in a transaction that hasn't been ``abort()``'ed or
``commit()``'ed). It was missing the case where the only pending
modifications were made in subtransactions. This has been fixed. If an
attempt to close a connection with pending subtransactions is made now::
ConnnectionStateError: Cannot close a connection with a pending subtransaction
is raised.
transaction
-----------
- Transactions have new, backward-incompatible behavior in one respect:
if a ``Transaction.commit()``, ``Transaction.commit(False)``, or
``Transaction.commit(True)`` raised an exception, prior behavior was that
the transaction effectively aborted, and a new transaction began.
A primary bad consequence was that, if in a sequence of subtransaction
commits, one of the commits failed but the exception was suppressed,
all changes up to and including the failing commit were lost, but
later subtransaction commits in the sequence got no indication that
something had gone wrong, nor did the final (top level) commit. This
could easily lead to inconsistent data being committed, from the
application's point of view.
The new behavior is that a failing commit "sticks" until explicitly
cleared. Now if an exception is raised by a ``commit()`` call (whether
subtransaction or top level) on a Transaction object ``T``:
- Pending changes are aborted, exactly as they were for a failing
commit before.
- But ``T`` remains the current transaction object (if ``tm`` is ``T``'s
transaction manger, ``tm.get()`` continues to return ``T``).
- All subsequent attempts to do ``T.commit()``, ``T.join()``, or
``T.register()`` raise the new ``TransactionFailedError`` exception.
Note that if you try to modify a persistent object, that object's
resource manager (usually a ``Connection`` object) will attempt to
``join()`` the failed transaction, and ``TransactionFailedError``
will be raised right away.
So after a transaction or subtransaction commit fails, that must be
explicitly cleared now, either by invoking ``abort()`` on the transaction
object, or by invoking ``begin()`` on its transaction manager.
- Some explanations of new transaction features in the 3.3a3 news
were incorrect, and this news file has been retroactively edited to
repair that. See news for 3.3a3 below.
- If ReadConflictError was raised by an attempt to load an object with a
``_p_independent()`` method that returned false, attempting to commit the
transaction failed to (re)raise ReadConflictError for that object. Note
that ZODB intends to prevent committing a transaction in which a
ReadConflictError occurred; this was an obscure case it missed.
- Growing pains: ZODB 3.2 had a bug wherein ``Transaction.begin()`` didn't
abort the current transaction if the only pending changes were in a
subtransaction. In ZODB 3.3, it's intended that a transaction manager be
used to effect ``begin()`` (instead of invoking ``Transaction.begin()``),
and calling ``begin()`` on a transaction manager didn't have this old
bug. However, ``Transaction.begin()`` still exists in 3.3, and it had a
worse bug: it never aborted the transaction (not even if changes were
pending outside of subtransactions). ``Transaction.begin()`` has been
changed to abort the transaction. ``Transaction.begin()`` is also
deprecated. Don't use it. Use ``begin()`` on the relevant transaction
manager instead. For example,
>>> import transaction
>>> txn = transaction.begin() # start a txn using the default TM
if using the default ``ThreadTransactionManager`` (see news for 3.3a3
below). In 3.3, it's intended that a single ``Transaction`` object is
used for exactly one transaction. So, unlike as in 3.2, when somtimes
``Transaction`` objects were reused across transactions, but sometimes
weren't, when you do ``Transaction.begin()`` in 3.3 a brand new
transaction object is created. That's why this use is deprecated. Code
of the form:
>>> txn = transaction.get()
>>> ...
>>> txn.begin()
>>> ...
>>> txn.commit()
can't work as intended in 3.3, because ``txn`` is no longer the current
``Transaction`` object the instant ``txn.begin()`` returns.
BTrees
------
The BTrees __init__.py file is now just a comment. It had been trying
to set up support for (long gone) "int sets", and to import an old
version of Zope's Interface package, which doesn't even ship with ZODB.
The latter in particular created problems, at least clashing with
PythonCAD's Interface package.
POSException
------------
Collector #1488 (TemporaryStorage -- going backward in time). This
confusion was really due to that the detail on a ConflictError exception
didn't make sense. It called the current revision "was", and the old
revision "now". The detail is much more informative now. For example,
if the exception said::
ConflictError: database conflict error (oid 0xcb22,
serial was 0x03441422948b4399, now 0x034414228c3728d5)
before, it now says::
ConflictError: database conflict error (oid 0xcb22,
serial this txn started with 0x034414228c3728d5 2002-04-14 20:50:32.863000,
serial currently committed 0x03441422948b4399 2002-04-14 20:50:34.815000)
ConflictError
-------------
The undocumented ``get_old_serial()`` and ``get_new_serial()`` methods
were swapped (the first returned the new serial, and the second returned
the old serial).
Tools
-----
``FileStorage.FileIterator`` was confused about how to read a transaction's
user and description fields, which caused several tools to display
binary gibberish for these values.
``ZODB.utils.oid_repr()`` changed to add a leading "0x", and to strip
leading zeroes. This is used, e.g., in the detail of a ``POSKeyError``
exception, to identify the missing oid. Before, the output was ambiguous.
For example, oid 17 was displayed as 0000000000000011. As a Python
integer, that's octal 9. Or was it meant to be decimal 11? Or was it
meant to be hex? Now it displays as 0x11.
fsrefs.py:
When run with ``-v``, produced tracebacks for objects whose creation was
merely undone. This was confusing. Tracebacks are now produced only
if there's "a real" problem loading an oid.
If the current revision of object O refers to an object P whose
creation has been undone, this is now identified as a distinct case.
Captured and ignored most attempts to stop it via Ctrl+C. Repaired.
Now makes two passes, so that an accurate report can be given of all
invalid references.
``analyze.py`` produced spurious "len of unsized object" messages when
finding a data record for an object uncreation or version abort. These
no longer appear.
``fsdump.py``'s ``get_pickle_metadata()`` function (which is used by several
tools) was confused about what to do when the ZODB pickle started with
a pickle ``GLOBAL`` opcode. It actually loaded the class then, which it
intends never to do, leading to stray messages on stdout when the class
wasn't available, and leading to a strange return value even when it was
available (the repr of the type object was returned as "the module name",
and an empty string was returned as "the class name"). This has been
repaired.
What's new in ZODB3 3.3 beta 2
==============================
Release date: 13-Aug-2004
Transaction Managers
--------------------
Zope3-dev Collector #139: Memory leak involving buckets and connections
The transaction manager internals effectively made every Connection
object immortal, except for those explicitly closed. Since typical
practice is not to close connections explicitly (and closing a DB
happens not to close the connections to it -- although that may
change), this caused massive memory leaks when many connections were
opened. The transaction manager internals were reworked to use weak
references instead, so that connection memory (and other registered
synch objects) now get cleaned up when nothing other than the
transaction manager knows about them.
Storages
--------
Collector #1327: FileStorage init confused by time travel
If the system clock "went backwards" a long time between the times a
FileStorage was closed and reopened, new transaction ids could be
smaller than transaction ids already in the storage, violating a
key invariant. Now transaction ids are guaranteed to be increasing
even when this happens. If time appears to have run backwards at all
when a FileStorage is opened, a new message saying so is logged at
warning level; if time appears to have run backwards at least 30
minutes, the message is logged at critical level (and you should
investigate to find and repair the true cause).
Tools
-----
repozo.py: Thanks to a suggestion from Toby Dickenson, backups
(whether incremental or full) are first written to a temp file now,
which is fsync'ed at the end, and only after that succeeds is the
file renamed to YYYY-MM-DD-HH-MM-SS.ext form. In case of a system
crash during a repozo backup, this at least makes it much less
likely that a backup file with incomplete or incorrect data will be
left behind.
fsrefs.py: Fleshed out the module docstring, and repaired a bug
wherein spurious error msgs could be produced after reporting a
problem with an unloadable object.
Test suite
----------
Collector #1397: testTimeStamp fails on FreeBSD
The BSD distributions are unique in that their mktime()
implementation usually ignores the input tm_isdst value. Test
checkFullTimeStamp() was sensitive to this platform quirk.
Reworked the way some of the ZEO tests use threads, so that unittest is
more likely to notice the real cause of a failure (which usually occurs in
a thread), and less likely to latch on to spurious problems resulting from
the real failure.
What's new in ZODB3 3.3 beta 1
==============================
Release date: 07-Jun-2004
3.3b1 is the first ZODB release built using the new zpkg tools:
http://zope.org/Members/fdrake/zpkgtools/
This appears to have worked very well. The structure of the tarball
release differs from previous releases because of it, and the set of
installed files includes some that were not installed in previous
releases. That shouldn't create problems, so let us know if it does!
We'll fine-tune this for the next release.
BTrees
------
Fixed bug indexing BTreeItems objects with negative indexes. This
caused reverse iteration to return each item twice. Thanks to Casey
Duncan for the fix.
ZODB
----
Methods removed from the database (ZODB.DB.DB) class: cacheStatistics(),
cacheMeanAge(), cacheMeanDeac(), and cacheMeanDeal(). These were
undocumented, untested, and unused. The first always returned an empty
tuple, and the rest always returned None.
When trying to do recovery to a time earlier than that of the most recent
full backup, repozo.py failed to find the appropriate files, erroneously
claiming "No files in repository before ". This has
been repaired.
Collector #1330: repozo.py -R can create corrupt .fs.
When looking for the backup files needed to recreate a Data.fs file,
repozo could (unintentionally) include its meta .dat files in the list,
or random files of any kind created by the user in the backup directory.
These would then get copied verbatim into the reconstructed file, filling
parts with junk. Repaired by filtering the file list to include only
files with the data extensions repozo.py creates (.fs, .fsz, .deltafs,
and .deltafsz). Thanks to James Henderson for the diagnosis.
fsrecover.py couldn't work, because it referenced attributes that no
longer existed after the MVCC changes. Repaired that, and added new
tests to ensure it continues working.
Collector #1309: The reference counts reported by DB.cacheExtremeDetails()
for ghosts were one too small. Thanks to Dieter Maurer for the diagnosis.
Collector #1208: Infinite loop in cPickleCache.
If a persistent object had a __del__ method (probably not a good idea
regardless, but we don't prevent it) that referenced an attribute of
self, the code to deactivate objects in the cache could get into an
infinite loop: ghostifying the object could lead to calling its __del__
method, the latter would load the object into cache again to
satsify the attribute reference, the cache would again decide that
the object should be ghostified, and so on. The infinite loop no longer
occurs, but note that objects of this kind still aren't sensible (they're
effectively immortal). Thanks to Toby Dickenson for suggesting a nice
cure.
What's new in ZODB3 3.3 alpha 3
===============================
Release date: 16-Apr-2004
transaction
-----------
There is a new transaction package, which provides new interfaces for
application code and for the interaction between transactions and
resource managers.
The top-level transaction package has functions ``commit()``, ``abort()``,
``get()``, and ``begin()``. They should be used instead of the magic
``get_transaction()`` builtin, which will be deprecated. For example:
>>> get_transaction().commit()
should now be written as
>>> import transaction
>>> transaction.commit()
The new API provides explicit transaction manager objects. A transaction
manager (TM) is responsible for associating resource managers with a
"current" transaction. The default TM, implemented by class
``ThreadedTransactionManager``, assigns each thread its own current
transaction. This default TM is available as ``transaction.manager``. The
``TransactionManager`` class assigns all threads to the same transaction,
and is an explicit replacement for the ``Connection.setLocalTransaction()``
method:
A transaction manager instance can be passed as the transaction_manager
argument to ``DB.open()``. If you do, the connection will use the specified
transaction manager instead of the default TM. The current transaction is
obtained by calling ``get()`` on a TM. For example:
>>> tm = transaction.TransactionManager()
>>> cn = db.open(transaction_manager=tm)
[...]
>>> tm.get().commit()
The ``setLocalTransaction()`` and ``getTransaction()`` methods of
Connection are deprecated. Use an explicit TM passed via
``transaction_manager=`` to ``DB.open()`` instead. The
``setLocalTransaction()`` method still works, but it returns a TM instead of
a Transaction.
A TM creates Transaction objects, which are used for exactly one
transaction. Transaction objects still have ``commit()``, ``abort()``,
``note()``, ``setUser()``, and ``setExtendedInfo()`` methods.
Resource managers, e.g. Connection or RDB adapter, should use a
Transaction's ``join()`` method instead of its ``register()`` method. An
object that calls ``join()`` manages its own resources. An object that
calls ``register()`` expects the TM to manage the objects.
Data managers written against the ZODB 4 transaction API are now
supported in ZODB 3.
persistent
----------
A database can now contain persistent weak references. An object that
is only reachable from persistent weak references will be removed by
pack().
The persistence API now distinguishes between deactivation and
invalidation. This change is intended to support objects that can't
be ghosts, like persistent classes. Deactivation occurs when a user
calls _p_deactivate() or when the cache evicts objects because it is
full. Invalidation occurs when a transaction updates the object. An
object that can't be a ghost must load new state when it is
invalidated, but can ignore deactivation.
Persistent objects can implement a __getnewargs__() method that will
be used to provide arguments that should be passed to __new__() when
instances (including ghosts) are created. An object that implements
__getnewargs__() must be loaded from storage even to create a ghost.
There is new support for writing hooks like __getattr__ and
__getattribute__. The new hooks require that user code call special
persistence methods like _p_getattr() inside their hook. See the ZODB
programming guide for details.
The format of serialized persistent references has changed; that is,
the on-disk format for references has changed. The old format is
still supported, but earlier versions of ZODB will not be able to read
the new format.
ZODB
----
Closing a ZODB Connection while it is registered with a transaction,
e.g. has pending modifications, will raise a ConnnectionStateError.
Trying to load objects from or store objects to a closed connection
will also raise a ConnnectionStateError.
ZODB connections are synchronized on commit, even when they didn't
modify objects. This feature assumes that the thread that opened the
connection is also the thread that uses it. If not, this feature will
cause problems. It can be disabled by passing synch=False to open().
New broken object support.
New add() method on Connection. User code should not assign the
_p_jar attribute of a new persistent object directly; a deprecation
warning is issued in this case.
Added a get() method to Connection as a preferred synonym for
__getitem__().
Several methods and/or specific optional arguments of methods have
been deprecated. The cache_deactivate_after argument used by DB() and
Connection() is deprecated. The DB methods getCacheDeactivateAfter(),
getVersionCacheDeactivateAfter(), setCacheDeactivateAfter(), and
setVersionCacheDeactivateAfter() are also deprecated.
The old-style undo() method was removed from the storage API, and
transactionalUndo() was renamed to undo().
The BDBStorages are no longer distributed with ZODB.
Fixed a serious bug in the new pack implementation. If pack was
called on the storage and passed a time earlier than a previous pack
time, data could be lost. In other words, if there are any two pack
calls, where the time argument passed to the second call was earlier
than the first call, data loss could occur. The bug was fixed by
causing the second call to raise a StorageError before performing any
work.
Fixed a rare bug in pack: if a pack started during a small window of
time near the end of a concurrent transaction's commit, it was possible
for the pack attempt to raise a spurious
CorruptedError: ... transaction with checkpoint flag set
exception. This did no damage to the database, or to the transaction
in progress, but no pack was performed then.
By popular demand, FileStorage.pack() no longer propagates a
FileStorageError: The database has already been packed to a
later time or no changes have been made since the last pack
exception. Instead that message is logged (at INFO level), and
the pack attempt simply returns then (no pack is performed).
ZEO
---
Fixed a bug that prevented the -m / --monitor argument from working.
zdaemon
-------
Added a -m / --mask option that controls the umask of the subprocess.
zLOG
----
The zLOG backend has been removed. zLOG is now just a facade over the
standard Python logging package. Environment variables like
STUPID_LOG_FILE are no longer honored. To configure logging, you need
to follow the directions in the logging package documentation. The
process is currently more complicated than configured zLOG. See
test.py for an example.
ZConfig
-------
This release of ZODB contains ZConfig 2.1.
More documentation has been written.
Make sure keys specified as attributes of the element are
converted by the appropriate key type, and are re-checked for derived
sections.
Refactored the ZConfig.components.logger schema components so that a
schema can import just one of the "eventlog" or "logger" sections if
desired. This can be helpful to avoid naming conflicts.
Added a reopen() method to the logger factories.
Always use an absolute pathname when opening a FileHandler.
Miscellaneous
-------------
The layout of the ZODB source release has changed. All the source
code is contained in a src subdirectory. The primary motivation for
this change was to avoid confusion caused by installing ZODB and then
testing it interactively from the source directory; the interpreter
would find the uncompiled ZODB package in the source directory and
report an import error.
A reference-counting bug was fixed, in the logic calling a modified
persistent object's data manager's register() method. The primary symptom
was rare assertion failures in Python's cyclic garbage collection.
The Connection class's onCommitAction() method was removed.
Some of the doc strings in ZODB are now written for processing by
epydoc.
Several new test suites were written using doctest instead of the
standard unittest TestCase framework.
MappingStorage now implements getTid().
ThreadedAsync: Provide a way to shutdown the servers using an exit
status.
The mkzeoinstance script looks for a ZODB installation, not a Zope
installation. The received wisdom is that running a ZEO server
without access to the appserver code avoids many mysterious problems.
What's new in ZODB3 3.3 alpha 2
===============================
Release date: 06-Jan-2004
This release contains a major overhaul of the persistence machinery,
including some user-visible changes. The Persistent base class is now
a new-style class instead of an ExtensionClass. The change enables
the use of features like properties with persistent object classes.
The Persistent base class is now contained in the persistent package.
The Persistence package is included for backwards compatibility. The
Persistence package is used by Zope to provide special
ExtensionClass-compatibility features like a non-C3 MRO and an __of__
method. ExtensionClass is not included with this release of ZODB3.
If you use the Persistence package, it will print a warning and import
Persistent from persistent.
In short, the new persistent package is recommended for non-Zope
applications. The following dotted class names are now preferred over
earlier names:
- persistent.Persistent
- persistent.list.PersistentList
- persistent.mapping.PersistentMapping
- persistent.TimeStamp
The in-memory, per-connection object cache (pickle cache) was changed
to participate in garbage collection. This should reduce the number
of memory leaks, although we are still tracking a few problems.
Multi-version concurrency control
---------------------------------
ZODB now supports multi-version concurrency control (MVCC) for
storages that support multiple revisions. FileStorage and
BDBFullStorage both support MVCC. In short, MVCC means that read
conflicts should almost never occur. When an object is modified in
one transaction, other concurrent transactions read old revisions of
the object to preserve consistency. In earlier versions of ZODB, any
access of the modified object would raise a ReadConflictError.
The ZODB internals changed significantly to accommodate MVCC. There
are relatively few user visible changes, aside from the lack of read
conflicts. It is possible to disable the MVCC feature using the mvcc
keyword argument to the DB open() method, ex.: db.open(mvcc=False).
ZEO
---
Changed the ZEO server and control process to work with a single
configuration file; this is now the default way to configure these
processes. (It's still possible to use separate configuration files.)
The ZEO configuration file can now include a "runner" section used by
the control process and ignored by the ZEO server process itself. If
present, the control process can use the same configuration file.
Fixed a performance problem in the logging code for the ZEO protocol.
The logging code could call repr() on arbitrarily long lists, even
though it only logged the first 60 bytes; worse, it called repr() even
if logging was currently disabled. Fixed to call repr() on individual
elements until the limit is reached.
Fixed a bug in zrpc (when using authentication) where the MAC header
wasn't being read for large messages, generating errors while unpickling
commands sent over the wire. Also fixed the zeopasswd.py script, added
testcases and provided a more complete commandline interface.
Fixed a misuse of the _map variable in zrpc Connectio objects, which
are also asyncore.dispatcher objects. This allows ZEO to work with
CVS Python (2.4). _map is used to indicate whether the dispatcher
users the default socket_map or a custom socket_map. A recent change
to asyncore caused it to use _map in its add_channel() and
del_channel() methods, which presumes to be a bug fix (may get ported
to 2.3). That causes our dubious use of _map to be a problem, because
we also put the Connections in the global socket_map. The new
asyncore won't remove it from the global socket map, because it has a
custom _map.
The prefix used for log messages from runzeo.py was changed from
RUNSVR to RUNZEO.
Miscellaneous
-------------
ReadConflictError objects now have an ignore() method. Normally, a
transaction that causes a read conflict can't be committed. If the
exception is caught and its ignore() method called, the transaction
can be committed. Application code may need this in advanced
applications.
What's new in ZODB3 3.3 alpha 1
===============================
Release date: 17-Jul-2003
New features of Persistence
---------------------------
The Persistent base class is a regular Python type implemented in C.
It should be possible to create new-style classes that inherit from
Persistent, and, thus, use all the new Python features introduced in
Python 2.2 and 2.3.
The __changed__() method on Persistent objects is no longer supported.
New features in BTrees
----------------------
BTree, Bucket, TreeSet and Set objects are now iterable objects, playing
nicely with the iteration protocol introduced in Python 2.2, and can
be used in any context that accepts an iterable object. As for Python
dicts, the iterator constructed for BTrees and Buckets iterates
over the keys.
>>> from BTrees.OOBTree import OOBTree
>>> b = OOBTree({"one": 1, "two": 2, "three": 3, "four": 4})
>>> for key in b: # iterates over the keys
... print key
four
one
three
two
>>> list(enumerate(b))
[(0, 'four'), (1, 'one'), (2, 'three'), (3, 'two')]
>>> i = iter(b)
>>> i.next()
'four'
>>> i.next()
'one'
>>> i.next()
'three'
>>> i.next()
'two'
>>>
As for Python dicts in 2.2, BTree and Bucket objects have new
.iterkeys(), .iteritems(), and .itervalues() methods. TreeSet and Set
objects have a new .iterkeys() method. Unlike as for Python dicts,
these new methods accept optional min and max arguments to effect
range searches. While Bucket.keys() produces a list, Bucket.iterkeys()
produces an iterator, and similarly for Bucket values() versus
itervalues(), Bucket items() versus iteritems(), and Set keys() versus
iterkeys(). The iter{keys,values,items} methods of BTrees and the
iterkeys() method of Treesets also produce iterators, while their
keys() (etc) methods continue to produce BTreeItems objects (a form of
"lazy" iterator that predates Python 2.2's iteration protocol).
>>> sum(b.itervalues())
10
>>> zip(b.itervalues(), b.iterkeys())
[(4, 'four'), (1, 'one'), (3, 'three'), (2, 'two')]
>>>
BTree, Bucket, TreeSet and Set objects also implement the __contains__
method new in Python 2.2, which means that testing for key membership
can be done directly now via the "in" and "not in" operators:
>>> "won" in b
False
>>> "won" not in b
True
>>> "one" in b
True
>>>
All old and new range-search methods now accept keyword arguments,
and new optional excludemin and excludemax keyword arguments. The
new keyword arguments allow doing a range search that's exclusive
at one or both ends (doesn't include min, and/or doesn't include
max).
>>> list(b.keys())
['four', 'one', 'three', 'two']
>>> list(b.keys(max='three'))
['four', 'one', 'three']
>>> list(b.keys(max='three', excludemax=True))
['four', 'one']
>>>
Other improvements
------------------
The exceptions generated by write conflicts now contain the name of
the conflicted object's class. This feature requires support for the
storage. All the standard storages support it.
What's new in ZODB3 3.2
========================
Release date: 08-Oct-2003
Nothing has changed since release candidate 1.
What's new in ZODB3 3.2 release candidate 1
===========================================
Release date: 01-Oct-2003
Added a summary to the Doc directory. There are several new documents
in the 3.2 release, including "Using zdctl and zdrun to manage server
processes" and "Running a ZEO Server HOWTO."
Fixed ZEO's protocol negotiation mechanism so that a client ZODB 3.1
can talk to a ZODB 3.2 server.
Fixed a memory leak in the ZEO server. The server was leaking a few
KB of memory per connection.
Fixed a memory leak in the ZODB object cache (cPickleCache). The
cache did not release two references to its Connection, causing a
large cycle of objects to leak when a database was closed.
Fixed a bug in the ZEO code that caused it to leak socket objects on
Windows. Specifically, fix the trigger mechanism so that both sockets
created for a trigger are closed.
Fixed a bug in the ZEO storage server that caused it to leave temp
files behind. The CommitLog class contains a temp file, but it was
not closing the file.
Changed the order of setuid() and setgid() calls in zdrun, so that
setgid() is called first.
Added a timeout to the ZEO test suite that prevents hangs. The test
suite creates ZEO servers with randomly assigned ports. If the port
happens to be in use, the test suite would hang because the ZEO client
would never stop trying to connect. The fix will cause the test to
fail after a minute, but should prevent the test runner from hanging.
The logging package was updated to include the latest version of the
logging package from Python CVS. Note that this package is only
installed for Python 2.2. In later versions of Python, it is
available in the Python standard library.
The ZEO1 directory was removed from the source distribution. ZEO1 is
not supported, and we never intended to include it in the release.
What's new in ZODB3 3.2 beta 3
==============================
Release date: 23-Sep-2003
Note: The changes listed for this release include changes also made in
ZODB 3.1.x releases and ported to the 3.2 release.
This version of ZODB 3.2 is not compatible with Python 2.1. Early
versions were explicitly designed to be compatible with Zope 2.6.
That plan has been dropped, because Zope 2.7 is already in beta
release.
Several of the classes in ZEO and ZODB now inherit from object, making
them new-style classes. The primary motivation for the change was to
make it easier to debug memory leaks. We don't expect any behavior to
change as a result.
A new feature to allow removal of connection pools for versions was
ported from Zope 2.6. This feature is needed by Zope to avoid denial
of service attacks that allow a client to create an arbitrary number
of version pools.
Fixed several critical ZEO bugs.
- If several client transactions were blocked waiting for the storage
and one of the blocked clients disconnected, the server would
attempt to restart one of the other waiting clients. Since the
disconnected client did not have the storage lock, this could lead
to deadlock. It could also cause the assertion "self._client is
None" to fail.
- If a storage server fails or times out between the vote and the
finish, the ZEO cache could get populated with objects that didn't
make it to the storage server.
- If a client loses its connection to the server near the end of a
transaction, it is now guaranteed to get a ClientDisconnected error
even if it reconnects before the transaction finishes. This is
necessary because the server will always abort the transaction.
In some cases, the client would never see an error for the aborted
transaction.
- In tpc_finish(), reordered the calls so that the server's tpc_finish()
is called (and must succeed) before we update the ZEO client cache.
- The storage name is now prepended to the sort key, to ensure a
unique global sort order if storages are named uniquely. This
can prevent deadlock in some unusual cases.
Fixed several serious flaws in the implementation of the ZEO
authentication protocol.
- The smac layer would accept a message without a MAC even after the
session key was established.
- The client never initialized its session key, so it never checked
incoming messages or created MACs for outgoing messags.
- The smac layer used a single HMAC instance for sending and receiving
messages. This approach could only work if client and server were
guaranteed to process all messages in the same total order, which
could only happen in simple scenarios like unit tests.
Fixed a bug in ExtensionClass when comparing ExtensionClass instances.
The code could raise RuntimeWarning under Python 2.3, and produce
incorrect results on 64-bit platforms.
Fixed bug in BDBStorage that could lead to DBRunRecoveryErrors when a
transaction was aborted after performing operations like commit
version or undo that create new references to existing pickles.
Fixed a bug in Connection.py that caused it to fail with an
AttributeError if close() was called after the database was closed.
The test suite leaves fewer log files behind, although it still leaves
a lot of junk. The test.py script puts each tests temp files in a
separate directory, so it is easier to see which tests are causing
problems. Unfortunately, it is still to tedious to figure out why the
identified tests are leaving files behind.
This release contains the latest and greatest version of the
BDBStorage. This storage has still not seen testing in a production
environment, but it represents the current best design and most recent
code culled from various branches where development has occurred.
The Tools directory contains a number of small improvements, a few new
tools, and README.txt that catalogs the tools. Many of the tools are
installed by setup.py; those scripts will now have a #! line set
automatically on Unix.
Fixed bugs in Tools/repozo.py, including a timing-dependent one that
could cause the following invocation of repozo to do a full backup when
an incremental backup would have sufficed.
A pair of new scripts from Jim Fulton can be used to synthesize
workloads and measure ZEO performance: see zodbload.py and
zeoserverlog.py in the Tools directory. Note that these require
Zope.
Tools/checkbtrees.py was strengthened in two ways:
- In addition to running the _check() method on each BTree B found,
BTrees.check.check(B) is also run. The check() function was written
after checkbtrees.py, and identifies kinds of damage B._check()
cannot find.
- Cycles in the object graph no longer lead to unbounded output.
Note that preventing this requires remembering the oid of each
persistent object found, which increases the memory needed by the
script.
What's new in ZODB3 3.2 beta 2
==============================
Release date: 16-Jun-2003
Fixed critical race conditions in ZEO's cache consistency code that
could cause invalidations to be lost or stale data to be written to
the cache. These bugs can lead to data loss or data corruption.
These bugs are relatively unlikely to be provoked in sites with few
conflicts, but the possibility of failure existed any time an object
was loaded and stored concurrently.
Fixed a bug in conflict resolution that failed to ghostify an object
if it was involved in a conflict. (This code may be redundant, but it
has been fixed regardless.)
The ZEO server was fixed so that it does not perform any I/O until all
of a transactions' invalidations are queued. If it performs I/O in the
middle of sending invalidations, it would be possible to overlap a
load from a client with the invalidation being sent to it.
The ZEO cache now handles invalidations atomically. This is the same
sort of bug that is described in the 3.1.2b1 section below, but it
affects the ZEO cache.
Fixed several serious bugs in fsrecover that caused it to fail
catastrophically in certain cases because it thought it had found a
checkpoint (status "c") record when it was in the middle of the file.
Two new features snuck into this beta release.
The ZODB.transact module provides a helper function that converts a
regular function or method into a transactional one.
The ZEO client cache now supports Adaptable Persistence (APE). The
cache used to expect that all OIDs were eight bytes long.
What's new in ZODB3 3.2 beta 1
==============================
Release date: 30-May-2003
ZODB
----
Invalidations are now processed atomically. Each transaction will see
all the changes caused by an earlier transaction or none of them.
Before this patch, it was possible for a transaction to see invalid
data because it saw only a subset of the invalidations. This is the
most likely cause of reported BTrees corruption, where keys were
stored in the wrong bucket. When a BTree bucket splits, the bucket
and the bucket's parent are both modified. If a transaction sees the
invalidation for the bucket but not the parent, the BTree in memory
will be internally inconsistent and keys can be put in the wrong
bucket. The atomic invalidation fix prevents this problem.
A number of minor reference count fixes in the object cache were
fixed. That's the cPickleCache.c file.
It was possible for a transaction that failed in tpc_finish() to lose
the traceback that caused the failure. The transaction code was fixed
to report the original error as well as any errors that occur while
trying to recover from the original error.
The "other" argument to copyTransactionsFrom() only needs to have an
.iterator() method. For convenience, change FileStorage's and
BDBFullStorage's iterator to have this method, which just returns
self.
Mount points are now visible from mounted objects.
Fixed memory leak involving database connections and caches. When a
connection or database was closed, the cache and database leaked,
because of a circular reference involving the cache. Fixed the cache
to explicitly clear out its contents when its connection is closed.
The ZODB cache has fewer methods. It used to expose methods that
could mutate the dictionary, which allowed users to violate internal
invariants.
ZConfig
-------
It is now possible to configure ZODB databases and storages and ZEO
servers using ZConfig.
ZEO & zdaemon
-------------
ZEO now supports authenticated client connections. The default
authentication protocol uses a hash-based challenge-response protocol
to prove identity and establish a session key for message
authentication. The architecture is pluggable to allow third-parties
to developer better authentication protocols.
There is a new HOWTO for running a ZEO server. The draft in this
release is incomplete, but provides more guidance than previous
releases. See the file Doc/ZEO/howto.txt.
The ZEO storage server's transaction timeout feature was refactored
and made slightly more rebust.
A new ZEO utility script, ZEO/mkzeoinst.py, was added. This creates a
standard directory structure and writes a configuration file with
mostly default values, and a bootstrap script that can be used to
manage and monitor the server using zdctl.py (see below).
Much work was done to improve zdaemon's zdctl.py and zdrun.py scripts.
(In the alpha 1 release, zdrun.py was called zdaemon.py, but
installing it in /bin caused much breakage due to the name
conflict with the zdaemon package.) Together with the new
mkzeoinst.py script, this makes controlling a ZEO server a breeze.
A ZEO client will not read from its cache during cache verification.
This fix was necessary to prevent the client from reading inconsistent
data.
The isReadOnly() method of a ZEO client was fixed to return the false
when the client is connected to a read-only fallback server.
The sync() method of ClientStorage and the pending() method of a zrpc
connection now do both input and output.
The short_repr() function used to generate log messages was fixed so
that it does not blow up creating a repr of very long tuples.
Storages
--------
FileStorage has a new pack() implementation that fixes several
reported problems that could lead to data loss.
Two small bugs were fixed in DemoStorage. undoLog() did not handle
its arguments correctly and pack() could accidentally delete objects
created in versions.
Fixed trivial bug in fsrecover that prevented it from working at all.
FileStorage will use fsync() on Windows starting with Python 2.2.3.
FileStorage's commit version was fixed. It used to stop after the
first object, leaving all the other objects in the version.
BTrees
------
Trying to store an object of a non-integer type into an IIBTree
or OIBTree could leave the bucket in a variety of insane states. For
example, trying
b[obj] = "I'm a string, not an integer"
where b is an OIBTree. This manifested as a refcount leak in the test
suite, but could have been much worse (most likely in real life is that
a seemingly arbitrary existing key would "go missing").
When deleting the first child of a BTree node with more than one
child, a reference to the second child leaked. This could cause
the entire bucket chain to leak (not be collected as garbage
despite not being referenced anymore).
Other minor BTree leak scenarios were also fixed.
Tools
-----
New tool zeoqueue.py for parsing ZEO log files, looking for blocked
transactions.
New tool repozo.py (originally by Anthony Baxter) for performing
incremental backups of Data.fs files.
The fsrecover.py script now does a better job of recovering from
errors the occur in the middle of a transaction record. Fixed several
bugs that caused partial or total failures in earlier versions.
What's new in ZODB3 3.2 alpha 1
===============================
Release date: 17-Jan-2003
Most of the changes in this release are performance and stability
improvements to ZEO. A major packaging change is that there won't be
a separate ZEO release. The new ZConfig is a noteworthy addtion (see
below).
ZODB
----
An experimental new transaction API was added. The Connection class
has a new method, setLocalTransaction(). ZODB applications can call
this method to bind transactions to connections rather than threads.
This is especially useful for GUI applications, which often have only
one thread but multiple independent activities within that thread
(generally one per window). Thanks to Christian Reis for championing
this feature.
Applications that take advantage of this feature should not use the
get_transaction() function. Until now, ZODB itself sometimes assumed
get_transaction() was the only way to get the transaction. Minor
corrections have been added. The ZODB test suite, on the other hand,
can continue to use get_transaction(), since it is free to assume that
transactions are bound to threads.
ZEO
---
There is a new recommended script for starting a storage server. We
recommend using ZEO/runzeo.py instead of ZEO/start.py. The start.py
script is still available in this release, but it will no longer be
maintained and will eventually be removed.
There is a new zdaemon implementation. This version is a separate
script that runs an arbitrary daemon. To run the ZEO server as a
daemon, you would run "zdrun.py runzeo.py". There is also a simple
shell, zdctl.py, that can be used to manage a daemon. Try
"zdctl.py -p runzeo.py".
There is a new version of the ZEO protocol in this release and a first
stab at protocol negotiation. (It's a first stab because the protocol
checking supporting in ZODB 3.1 was too primitive to support anything
better.) A ZODB 3.2 ZEO client can talk to an old server, but a ZODB
3.2 server can't talk to an old client. It's safe to upgrade all the
clients first and upgrade the server last. The ZEO client cache
format changed, so you'll need to delete persistent caches before
restarting clients.
The ZEO cache verification protocol was revised to require many fewer
messages in cases where a client or server restarts quickly.
The performance of full cache verification has improved dramatically.
Measurements from Jim were somewhere in 2x-5x. The
implementation was fixed to use the very-fast getSerial() method on
the storage instead of the comparatively slow load().
The ZEO server has an optional timeout feature that will abort a
connection that does not commit within a certain amount of time. The
timeout works by closing the socket the client is using, causing both
client and server to abort the transaction and continue. This is a
drastic step, but can be useful to prevent a hung client or other bug
from blocking a server indefinitely.
A bug was fixed in the ZEO protocol that allowed clients to read stale
cache data while cache verification was being performed. The fixed
version prevents the client from using the storage until after
verification completes.
The ZEO server has an experimental monitoring interface that reports
usage statistics for the storage server including number of connected
clients and number of transactions active and committed. It can be
enabled by passing the -m flag to runsvr.py.
The ZEO ClientStorage no longer supports the environment variables
CLIENT_HOME, INSTANCE_HOME, or ZEO_CLIENT.
The ZEO1 package is still included with this release, but there is no
longer an option to install it.
BTrees
------
The BTrees package now has a check module that inspects a BTree to
check internal invariants. Bugs in older versions of the code code
leave a BTree in an inconsistent state. Calling BTrees.check.check()
on a BTree object should verify its consistency. (See the NEWS
section for 3.1 beta 1 below to for the old BTrees bugs.)
Fixed a rare conflict resolution problem in the BTrees that could
cause an segfault when the conflict resolution resulted in any
empty bucket.
Installation
------------
The distutils setup now installs several Python scripts. The
runzeo.py and zdrun.py scripts mentioned above and several fsXXX.py
scripts from the Tools directory.
The test.py script does not run all the ZEO tests by default, because
the ZEO tests take a long time to run. Use --all to run all the
tests. Otherwise a subset of the tests, mostly using MappingStorage,
are run.
Storages
--------
There are two new storages based on Sleepycat's BerkeleyDB in the
BDBStorage package. Barry will have to write more here, because I
don't know how different they are from the old bsddb3Storage
storages. See Doc/BDBStorage.txt for more information.
It now takes less time to open an existing FileStorage. The
FileStorage uses a BTree-based index that is faster to pickle and
unpickle. It also saves the index periodically so that subsequent
opens will go fast even if the storage was not closed cleanly.
Misc
----
The new ZConfig package, which will be used by Zope and ZODB, is
included. ZConfig provides a configuration syntax, similar to
Apache's syntax. The package can be used to configure the ZEO server
and ZODB databases. See the module ZODB.config for functions to open
the database from configuration. See ZConfig/doc for more info.
The zLOG package now uses the logging package by Vinay Sajip, which
will be included in Python 2.3.
The Sync extension was removed from ExtensionClass, because it was not
used by ZODB.
What's new in ZODB3 3.1.4?
==========================
Release date: 11-Sep-2003
A new feature to allow removal of connection pools for versions was
ported from Zope 2.6. This feature is needed by Zope to avoid denial
of service attacks that allow a client to create an arbitrary number
of version pools.
A pair of new scripts from Jim Fulton can be used to synthesize
workloads and measure ZEO performance: see zodbload.py and
zeoserverlog.py in the Tools directory. Note that these require
Zope.
Tools/checkbtrees.py was strengthened in two ways:
- In addition to running the _check() method on each BTree B found,
BTrees.check.check(B) is also run. The check() function was written
after checkbtrees.py, and identifies kinds of damage B._check()
cannot find.
- Cycles in the object graph no longer lead to unbounded output.
Note that preventing this requires remembering the oid of each
persistent object found, which increases the memory needed by the
script.
What's new in ZODB3 3.1.3?
==========================
Release date: 18-Aug-2003
Fixed several critical ZEO bugs.
- If a storage server fails or times out between the vote and the
finish, the ZEO cache could get populated with objects that didn't
make it to the storage server.
- If a client loses its connection to the server near the end of a
transaction, it is now guaranteed to get a ClientDisconnected error
even if it reconnects before the transaction finishes. This is
necessary because the server will always abort the transaction.
In some cases, the client would never see an error for the aborted
transaction.
- In tpc_finish(), reordered the calls so that the server's tpc_finish()
is called (and must succeed) before we update the ZEO client cache.
- The storage name is now prepended to the sort key, to ensure a
unique global sort order if storages are named uniquely. This
can prevent deadlock in some unusual cases.
A variety of fixes and improvements to Berkeley storage (aka BDBStorage)
were back-ported from ZODB 4. This release now contains the most
current version of the Berkeley storage code. Many tests have been
back-ported, but not all.
Modified the Windows tests to wait longer at the end of ZEO tests for
the server to shut down. Before Python 2.3, there is no waitpid() on
Windows, and, thus, no way to know if the server has shut down. The
change makes the Windows ZEO tests much less likely to fail or hang,
at the cost of increasing the time needed to run the tests.
Fixed a bug in ExtensionClass when comparing ExtensionClass instances.
The code could raise RuntimeWarning under Python 2.3, and produce
incorrect results on 64-bit platforms.
Fixed bugs in Tools/repozo.py, including a timing-dependent one that
could cause the following invocation of repozo to do a full backup when
an incremental backup would have sufficed.
Added Tools/README.txt that explains what each of the scripts in the
Tools directory does.
There were many small changes and improvements to the test suite.
What's new in ZODB3 3.1.2 final?
================================
Fixed bug in FileStorage pack that caused it to fail if it encountered
an old undo record (status "u").
Fixed several bugs in FileStorage pack that could cause OverflowErrors
for storages > 2 GB.
Fixed memory leak in TimeStamp.laterThan() that only occurred when it
had to create a new TimeStamp.
Fixed two BTree bugs that were fixed on the head a while ago:
- bug in fsBTree that would cause byValue searches to end early.
(fsBTrees are never used this way, but it was still a bug.)
- bug that lead to segfault if BTree was mutated via deletion
while it was being iterated over.
What's new in ZODB3 3.1.2 beta 2?
=================================
Fixed critical race conditions in ZEO's cache consistency code that
could cause invalidations to be lost or stale data to be written to
the cache. These bugs can lead to data loss or data corruption.
These bugs are relatively unlikely to be provoked in sites with few
conflicts, but the possibility of failure existed any time an object
was loaded and stored concurrently.
Fixed a bug in conflict resolution that failed to ghostify an object
if it was involved in a conflict. (This code may be redundant, but it
has been fixed regardless.)
The ZEO server was fixed so that it does not perform any I/O until all
of a transactions' invalidations are queued. If it performs I/O in the
middle of sending invalidations, it would be possible to overlap a
load from a client with the invalidation being sent to it.
The ZEO cache now handles invalidations atomically. This is the same
sort of bug that is described in the 3.1.2b1 section below, but it
affects the ZEO cache.
Fixed several serious bugs in fsrecover that caused it to fail
catastrophically in certain cases because it thought it had found a
checkpoint (status "c") record when it was in the middle of the file.
What's new in ZODB3 3.1.2 beta 1?
=================================
ZODB
----
Invalidations are now processed atomically. Each transaction will see
all the changes caused by an earlier transaction or none of them.
Before this patch, it was possible for a transaction to see invalid
data because it saw only a subset of the invalidations. This is the
most likely cause of reported BTrees corruption, where keys were
stored in the wrong bucket. When a BTree bucket splits, the bucket
and the bucket's parent are both modified. If a transaction sees the
invalidation for the bucket but not the parent, the BTree in memory
will be internally inconsistent and keys can be put in the wrong
bucket. The atomic invalidation fix prevents this problem.
A number of minor reference count fixes in the object cache were
fixed. That's the cPickleCache.c file.
It was possible for a transaction that failed in tpc_finish() to lose
the traceback that caused the failure. The transaction code was fixed
to report the original error as well as any errors that occur while
trying to recover from the original error.
ZEO
---
A ZEO client will not read from its cache during cache verification.
This fix was necessary to prevent the client from reading inconsistent
data.
The isReadOnly() method of a ZEO client was fixed to return the false
when the client is connected to a read-only fallback server.
The sync() method of ClientStorage and the pending() method of a zrpc
connection now do both input and output.
The short_repr() function used to generate log messages was fixed so
that it does not blow up creating a repr of very long tuples.
Storages
--------
FileStorage has a new pack() implementation that fixes several
reported problems that could lead to data loss.
Two small bugs were fixed in DemoStorage. undoLog() did not handle
its arguments correctly and pack() could accidentally delete objects
created in versions.
Fixed trivial bug in fsrecover that prevented it from working at all.
FileStorage will use fsync() on Windows starting with Python 2.2.3.
FileStorage's commit version was fixed. It used to stop after the
first object, leaving all the other objects in the version.
BTrees
------
Trying to store an object of a non-integer type into an IIBTree
or OIBTree could leave the bucket in a variety of insane states. For
example, trying
b[obj] = "I'm a string, not an integer"
where b is an OIBTree. This manifested as a refcount leak in the test
suite, but could have been much worse (most likely in real life is that
a seemingly arbitrary existing key would "go missing").
When deleting the first child of a BTree node with more than one
child, a reference to the second child leaked. This could cause
the entire bucket chain to leak (not be collected as garbage
despite not being referenced anymore).
Other minor BTree leak scenarios were also fixed.
Other
-----
Comparing a Missing.Value object to a C type that provide its own
comparison operation could lead to a segfault when the Missing.Value
was on the right-hand side of the comparison operator. The Missing
class was fixed so that its coercion and comparison operations are
safe.
Tools
-----
Four tools are now installed by setup.py: fsdump.py, fstest.py,
repozo.py, and zeopack.py.
What's new in ZODB3 3.1.1 final?
================================
Release date: 11-Feb-2003
Tools
-----
Updated repozo.py tool
What's new in ZODB3 3.1.1 beta 2?
=================================
Release date: 03-Feb-2003
The Transaction "hosed" feature is disabled in this release. If a
transaction fails during the tpc_finish() it is not possible, in
general, to know whether the storage is in a consistent state. For
example, a ZEO server may commit the data and then fail before sending
confirmation of the commit to the client. If multiple storages are
involved in a transaction, the problem is exacerbated: One storage may
commit the data while another fails to commit. In previous versions
of ZODB, the database would set a global "hosed" flag that prevented
any other transaction from committing until an administrator could
check the status of the various failed storages and ensure that the
database is in a consistent state. This approach favors data
consistency over availability. The new approach is to log a panic but
continue. In practice, availability seems to be more important than
consistency. The failure mode is exceedingly rare in either case.
The BTrees-based fsIndex for FileStorage is enabled. This version of
the index is faster to load and store via pickle and uses less memory
to store keys. We had intended to enable this feature in an earlier
release, but failed to actually do it; thus, it's getting enabled as a
bug fix now.
Two rare bugs were fixed in BTrees conflict resolution. The most
probable symptom of the bug would have been a segfault. The bugs
were found via synthetic stress tests rather than bug reports.
A value-based consistency checker for BTrees was added. See the
module BTrees.check for the checker and other utilities for working
with BTrees.
A new script called repozo.py was added. This script, originally
written by Anthony Baxter, provides an incremental backup scheme for
FileStorage based storages.
zeopack.py has been fixed to use a read-only connection.
Various small autopack-related race conditions have been fixed in the
Berkeley storage implementations. There have been some table changes
to the Berkeley storages so any storage you created in 3.1.1b1 may not
work. Part of these changes was to add a storage version number to
the schema so these types of incompatible changes can be avoided in
the future.
Removed the chance of bogus warnings in the FileStorage iterator.
ZEO
---
The ZEO version number was bumped to 2.0.2 on account of the following
minor feature additions.
The performance of full cache verification has improved dramatically.
Measurements from Jim were somewhere in 2x-5x. The
implementation was fixed to use the very-fast getSerial() method on
the storage instead of the comparatively slow load().
The ZEO server has an optional timeout feature that will abort a
connection that does not commit within a certain amount of time. The
timeout works by closing the socket the client is using, causing both
client and server to abort the transaction and continue. This is a
drastic step, but can be useful to prevent a hung client or other bug
from blocking a server indefinitely.
If a client was disconnected during a transaction, the tpc_abort()
call did not properly reset the internal state about the transaction.
The bug caused the next transaction to fail in its tpc_finish().
Also, any ClientDisconnected exceptions raised during tpc_abort() are
ignored.
ZEO logging has been improved by adding more logging for important
events, and changing the logging level for existing messages to a more
appropriate level (usually lower).
What's new in ZODB3 3.1.1 beta 1?
=================================
Release date: 10-Dev-2002
It was possible for earlier versions of ZODB to deadlock when using
multiple storages. If multiple transactions committed concurrently
and both transactions involved two or more shared storages, deadlock
was possible. This problem has been fixed by introducing a sortKey()
method to the transaction and storage APIs that is used to define an
ordering on transaction participants. This solution will prevent
deadlocks provided that all transaction participants that use locks
define a valid sortKey() method. A warning is raised if a participant
does not define sortKey(). For backwards compatibility, BaseStorage
provides a sortKey() that uses __name__.
Added code to ThreadedAsync/LoopCallback.py to work around a bug in
asyncore.py: a handled signal can cause unwanted reads to happen.
A bug in FileStorage related to object uncreation was fixed. If an
a transaction that created an object was undone, FileStorage could
write a bogus data record header that could lead to strange errors if
the object was loaded. An attempt to load an uncreated object now
raises KeyError, as expected.
The restore() implementation in FileStorage wrote incorrect
backpointers for a few corner cases involving versions and undo. It
also failed if the backpointer pointed to a record that was before the
pack time. These specific bugs have been fixed and new test cases
were added to cover them.
A bug was fixed in conflict resolution that raised a NameError when a
class involved in a conflict could not be loaded. The bug did not
affect correctness, but prevent ZODB from caching the fact that the
class was unloadable. A related bug prevented spurious
AttributeErrors when a class could not be loaded. It was also fixed.
The script Tools/zeopack.py was fixed to work with ZEO 2. It was
untested and had two silly bugs.
Some C extensions included standard header files before including
Python.h, which is not allowed. They now include Python.h first,
which eliminates compiler warnings in certain configurations.
The BerkeleyDB based storages have been merged from the trunk,
providing a much more robust version of the storages. They are not
backwards compatible with the old storages, but the decision was made
to update them in this micro release because the old storages did not
work for all practical purposes. For details, see Doc/BDBStorage.txt.
What's new in ZODB3 3.1 final?
===============================
Release date: 28-Oct-2002
If an error occurs during conflict resolution, the store will silently
catch the error, log it, and continue as if the conflict was
unresolvable. ZODB used to behave this way, and the change to catch
only ConflictError was causing problems in deployed systems. There
are a lot of legitimate errors that should be caught, but it's too
close to the final release to make the substantial changes needed to
correct this.
What's new in ZODB3 3.1 beta 3?
===============================
Release date: 21-Oct-2002
A small extension was made to the iterator protocol. The Record
objects, which are returned by the per-transaction iterators, contain
a new `data_txn` attribute. It is None, unless the data contained in
the record is a logical copy of an earlier transaction's data. For
example, when transactional undo modifies an object, it creates a
logical copy of the earlier transaction's data. Note that this
provide a stronger statement about consistency than whether the data
in two records is the same; it's possible for two different updates to
an object to coincidentally have the same data.
The restore() method was extended to take the data_txn attribute
mentioned above as an argument. FileStorage uses the new argument to
write a backpointer if possible.
A few bugs were fixed.
The setattr slot of the cPersistence C API was being initialized to
NULL. The proper initialization was restored, preventing crashes in
some applications with C extensions that used persistence.
The return value of TimeStamp's __cmp__ method was clipped to return
only 1, 0, -1.
The restore() method was fixed to write a valid backpointer if the
update being restored is in a version.
Several bugs and improvements were made to zdaemon, which can be used
to run the ZEO server. The parent now forwards signals to the child
as intended. Pidfile handling was improved and the trailing newline
was omitted.
What's new in ZODB3 3.1 beta 2?
===============================
Release date: 4-Oct-2002
A few bugs have been fixed, some that were found with the help of
Neal Norwitz's PyChecker.
The zeoup.py tool has been fixed to allow connecting to a read-only
storage, when the --nowrite option is given.
Casey Duncan fixed a few bugs in the recent changes to undoLog().
The fstest.py script no longer checks that each object modified in a
transaction has a serial number that matches the transaction id.
This invariant is no longer maintained; several new features in the
3.1 release depend on it.
The ZopeUndo package was added. If ZODB3 is being used to run a ZEO
server that will be used with Zope, it is usually best if the server
and the Zope client don't share any software. The Zope undo
framework, however, requires that a Prefix object be passed between
client and server. To support this use, ZopeUndo was created to hold
the Prefix object.
Many bugs were fixed in ZEO, and a couple of features added. See
`ZEO-NEWS.txt` for details.
The ZODB guide included in the Doc directory has been updated. It is
still incomplete, but most of the references to old ZODB packages have
been removed. There is a new section that briefly explains how to use
BTrees.
The zeoup.py tool connects using a read-only connection when --nowrite
is specifified. This feature is useful for checking on read-only ZEO
servers.
What's new in ZODB3 3.1 beta 1?
===============================
Release date: 12-Sep-2002
We've changed the name and version number of the project, but it's
still the same old ZODB. There have been a lot of changes since the
last release.
New ZODB cache
--------------
Toby Dickenson implemented a new Connection cache for ZODB. The cache
is responsible for pointer swizzling (translating between oids and
Python objects) and for keeping recently used objects in memory. The
new cache is a big improvement over the old cache. It strictly honors
its size limit, where size is specified in number of objects, and it
evicts objects in least recently used (LRU) order.
Users should take care when setting the cache size, which has a
default value of 400 objects. The old version of the cache often held
many more objects than its specified size. An application may not
perform as well with a small cache size, because the cache no longer
exceeds the limit.
Storages
--------
The index used by FileStorage was reimplemented using a custom BTrees
object. The index maps oids to file offsets, and is kept in memory at
all times. The new index uses about 1/4 the memory of the old,
dictionary-based index. See the module ZODB.fsIndex for details.
A security flaw was corrected in transactionalUndo(). The transaction
ids returned by undoLog() and used for transactionalUndo() contained a
file offset. An attacker could construct a pickle with a bogus
transaction record in its binary data, deduce the position of the
pickle in the file from the undo log, then submit an undo with a bogus
file position that caused the pickle to get written as a regular data
record. The implementation was fixed so that file offsets are not
included in the transaction ids.
Several storages now have an explicit read-only mode. For example,
passing the keyword argument read_only=1 to FileStorage will make it
read-only. If a write operation is performed on a read-only storage,
a ReadOnlyError will be raised.
The storage API was extended with new methods that support the Zope
Replication Service (ZRS), a proprietary Zope Corp product. We expect
these methods to be generally useful. The methods are:
- restore(oid, serialno, data, version, transaction)
Perform a store without doing consistency checks. A client can
use this method to provide a new current revision of an object.
The ``serialno`` argument is the new serialno to use for the
object, not the serialno of the previous revision.
- lastTransaction()
Returns the transaction id of the last committed transaction.
- lastSerial(oid)
Return the current serialno for ``oid`` or None.
- iterator(start=None, stop=None)
The iterator method isn't new, but the optional ``start`` and
``stop`` arguments are. These arguments can be used to specify
the range of the iterator -- an inclusive range [start, stop].
FileStorage is now more cautious about creating a new file when it
believes a file does not exist. This change is a workaround for bug
in Python versions upto and including 2.1.3. If the interpreter was
builtin without large file support but the platform had it,
os.path.exists() would return false for large files. The fix is to
try to open the file first, and decide whether to create a new file
based on errno.
The undoLog() and undoInfo() methods of FileStorage can run
concurrently with other methods. The internal storage lock is
released periodically to give other threads a chance to run. This
should increase responsiveness of ZEO clients when used with ZEO 2.
New serial numbers are assigned consistently for abortVersion() and
commitVersion(). When a version is committed, the non-version data
gets a new serial number. When a version is aborted, the serial
number for non-version data does not change. This means that the
abortVersion() transaction record has the unique property that its
transaction id is not the serial number of the data records.
Berkeley Storages
-----------------
Berkeley storage constructors now take an optional `config` argument,
which is an instance whose attributes can be used to configure such
BerkeleyDB policies as an automatic checkpointing interval, lock table
sizing, and the log directory. See bsddb3Storage/BerkeleyBase.py for
details.
A getSize() method has been added to all Berkeley storages.
Berkeley storages open their environments with the DB_THREAD flag.
Some performance optimizations have been implemented in Full storage,
including the addition of a helper C extension when used with Python
2.2. More performance improvements will be added for the ZODB 3.1
final release.
A new experimental Autopack storage was added which keeps only a
certain amount of old revision information. The concepts in this
storage will be folded into Full and Autopack will likely go away in
ZODB 3.1 final. ZODB 3.1 final will also have much improved Minimal
and Full storages, which eliminate Berkeley lock exhaustion problems,
reduce memory use, and improve performance.
It is recommended that you use BerkeleyDB 4.0.14 and PyBSDDB 3.4.0
with the Berkeley storages. See bsddb3Storage/README.txt for details.
BTrees
------
BTrees no longer ignore exceptions raised when two keys are compared.
Tim Peters fixed several endcase bugs in the BTrees code. Most
importantly, after a mix of inserts and deletes in a BTree or TreeSet, it
was possible (but unlikely) for the internal state of the object to become
inconsistent. Symptoms then varied; most often this manifested as a
mysterious failure to find a key that you knew was present, or that
tree.keys() would yield an object that disgreed with the tree about
how many keys there were.
If you suspect such a problem, BTrees and TreeSets now support a ._check()
method, which does a thorough job of examining the internal tree pointers
for consistency. It raises AssertionError if it finds any problems, else
returns None. If ._check() raises an exception, the object is damaged,
and rebuilding the object is the best solution. All known ways for a
BTree or TreeSet object to become internally inconsistent have been
repaired.
Other fixes include:
- Many fixes for range search endcases, including the "range search bug:"
If the smallest key S in a bucket in a BTree was deleted, doing a range
search on the BTree with S on the high end could claim that the range
was empty even when it wasn't.
- Zope Collector #419: repaired off-by-1 errors and IndexErrors when
slicing BTree-based data structures. For example,
an_IIBTree.items()[0:0] had length 1 (should be empty) if the tree
wasn't empty.
- The BTree module functions weightedIntersection() and weightedUnion()
now treat negative weights as documented. It's hard to explain what
their effects were before this fix, as the sign bits were getting
confused with an internal distinction between whether the result
should be a set or a mapping.
ZEO
----
For news about ZEO2, see the file ZEO-NEWS.txt.
This version of ZODB ships with two different versions of ZEO. It
includes ZEO 2.0 beta 1, the recommended new version. (ZEO 2 will
reach final release before ZODB3.) The ZEO 2.0 protocol is not
compatible with ZEO 1.0, so we have also included ZEO 1.0 to support
people already using ZEO 1.0.
Other features
--------------
When a ConflictError is raised, the exception object now has a
sensible structure, thanks to a patch from Greg Ward. The exception
now uses the following standard attributes: oid, class_name, message,
serials. See the ZODB.POSException.ConflictError doc string for
details.
It is now easier to customize the registration of persistent objects
with a transaction. The low-level persistence mechanism in
cPersistence.c registers with the object's jar instead of with the
current transaction. The jar (Connection) then registers with the
transaction. This redirection would allow specialized Connections to
change the default policy on how the transaction manager is selected
without hacking the Transaction module.
Empty transactions can be committed without interacting with the
storage. It is possible for registration to occur unintentionally and
for a persistent object to compensate by making itself as unchanged.
When this happens, it's possible to commit a transaction with no
modified objects. The change allows such transactions to finish even
on a read-only storage.
Two new tools were added to the Tools directory. The ``analyze.py``
script, based on a tool by Matt Kromer, prints a summary of space
usage in a FileStorage Data.fs. The ``checkbtrees.py`` script scans a
FileStorage Data.fs. When it finds a BTrees object, it loads the
object and calls the ``_check`` method. It prints warning messages
for any corrupt BTrees objects found.
Documentation
-------------
The user's guide included with this release is still woefully out of date.
Other bugs fixed
----------------
If an exception occurs inside an _p_deactivate() method, a traceback
is printed on stderr. Previous versions of ZODB silently cleared the
exception.
ExtensionClass and ZODB now work correctly with a Python debug build.
All C code has been fixed to use a consistent set of functions from
the Python memory API. This allows ZODB to be used in conjunction
with pymalloc, the default allocator in Python 2.3.
zdaemon, which can be used to run a ZEO server, more clearly reports
the exit status of its child processes.
The ZEO server will reinitialize zLOG when it receives a SIGHUP. This
allows log file rotation without restarting the server.
What's new in StandaloneZODB 1.0 final?
=======================================
Release date: 08-Feb-2002
All copyright notices have been updated to reflect the fact that the
ZPL 2.0 covers this release.
Added a cleanroom PersistentList.py implementation, which multiply
inherits from UserDict and Persistent.
Some improvements in setup.py and test.py for sites that don't have
the Berkeley libraries installed.
A new program, zeoup.py was added which simply verifies that a ZEO
server is reachable. Also, a new program zeopack.py was added which
connects to a ZEO server and packs it.
What's new in StandaloneZODB 1.0 c1?
====================================
Release Date: 25-Jan-2002
This was the first public release of the StandaloneZODB from Zope
Corporation. Everything's new! :)
ZODB-5.0.0b1/LICENSE.txt 0000664 0000000 0000000 00000004026 12750641745 0014335 0 ustar 00root root 0000000 0000000 Zope Public License (ZPL) Version 2.1
A copyright notice accompanies this license document that identifies the
copyright holders.
This license has been certified as open source. It has also been designated as
GPL compatible by the Free Software Foundation (FSF).
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions in source code must retain the accompanying copyright
notice, this list of conditions, and the following disclaimer.
2. Redistributions in binary form must reproduce the accompanying copyright
notice, this list of conditions, and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. Names of the copyright holders must not be used to endorse or promote
products derived from this software without prior written permission from the
copyright holders.
4. The right to distribute this software or to use it for any purpose does not
give you the right to use Servicemarks (sm) or Trademarks (tm) of the
copyright
holders. Use of them is covered by separate agreement with the copyright
holders.
5. If any files are modified, you must cause the modified files to carry
prominent notices stating that you changed the files and the date of any
change.
Disclaimer
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY EXPRESSED
OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
ZODB-5.0.0b1/MANIFEST.in 0000664 0000000 0000000 00000000411 12750641745 0014242 0 ustar 00root root 0000000 0000000 include *.rst
include *.txt
include *.py
include *.ini
include .coveragerc
include .travis.yml
include buildout.cfg
include COPYING
recursive-include doc *
recursive-include src *
global-exclude *.dll
global-exclude *.pyc
global-exclude *.pyo
global-exclude *.so
ZODB-5.0.0b1/README.rst 0000664 0000000 0000000 00000007754 12750641745 0014214 0 ustar 00root root 0000000 0000000 ====
ZODB
====
Introduction
============
The ZODB package provides a set of tools for using the Zope Object
Database (ZODB).
Our primary development platforms are Linux and Mac OS X. The test
suite should pass without error on these platforms and, hopefully,
Windows, although it can take a long time on Windows -- longer if you
use ZoneAlarm.
Compatibility
=============
ZODB 4.3 requires Python 2.7 or Python >= 3.3.
Travis: |buildstatus|_
winbot: |winbotstatus|_
Prerequisites
=============
You must have Python installed. If you're using a system Python
install, make sure development support is installed too.
You also need the transaction, BTrees, persistent, six, zc.lockfile, ZConfig,
zodbpickle, zope.interface packages, and optionally manuel and zope.testing.
If you don't have them and you can connect to the Python Package Index,
then these will be installed for you if you don't have them.
Installation
============
ZODB is released as a distutils package. The easiest ways to build
and install it are to use `easy_install
`_, or
`zc.buildout `_.
To install by hand, first install the dependencies listed in `Prerequisites`_.
These can be found in the `Python Package Index `_.
To run the tests, use the test setup command::
python setup.py test
It will download dependencies if needed. If this happens, ou may get
an import error when the test command gets to looking for tests. Try
running the test command a second time and you should see the tests
run.
::
python setup.py test
To install, use the install command::
python setup.py install
Testing for Developers
======================
The ZODB checkouts are `buildouts `_.
When working from a ZODB checkout, first run the bootstrap.py script
to initialize the buildout:
% python bootstrap.py
and then use the buildout script to build ZODB and gather the dependencies:
% bin/buildout
This creates a test script:
% bin/test -v
This command will run all the tests, printing a single dot for each
test. When it finishes, it will print a test summary. The exact
number of tests can vary depending on platform and available
third-party libraries.::
Ran 1182 tests in 241.269s
OK
The test script has many more options. Use the ``-h`` or ``--help``
options to see a file list of options. The default test suite omits
several tests that depend on third-party software or that take a long
time to run. To run all the available tests use the ``--all`` option.
Running all the tests takes much longer.::
Ran 1561 tests in 1461.557s
OK
Maintenance scripts
-------------------
Several scripts are provided with the ZODB and can help for analyzing,
debugging, checking for consistency, summarizing content, reporting space used
by objects, doing backups, artificial load testing, etc.
Look at the ZODB/script directory for more informations.
License
=======
ZODB is distributed under the Zope Public License, an OSI-approved
open source license. Please see the LICENSE.txt file for terms and
conditions.
More information
================
See http://zodb.org/
There is a Mailman mailing list in place to discuss all issues related
to ZODB. You can send questions to
zodb-dev@zope.org
or subscribe at
http://lists.zope.org/mailman/listinfo/zodb-dev
and view its archives at
http://lists.zope.org/pipermail/zodb-dev
Note that Zope Corp mailing lists have a subscriber-only posting policy.
Bugs and Patches
================
Bug reports and patches should be added to the Launchpad:
https://launchpad.net/zodb
.. |buildstatus| image:: https://api.travis-ci.org/zopefoundation/ZODB.png?branch=master
.. _buildstatus: https://travis-ci.org/zopefoundation/ZODB
.. |winbotstatus| image:: http://winbot.zope.org/buildstatusimage?builder=ZODB_dev%20py_270_win64&number=-1
.. _winbotstatus: http://winbot.zope.org/builders/ZODB_dev%20py_270_win64/builds/-1
ZODB-5.0.0b1/bootstrap.py 0000664 0000000 0000000 00000014545 12750641745 0015110 0 ustar 00root root 0000000 0000000 ##############################################################################
#
# Copyright (c) 2006 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Bootstrap a buildout-based project
Simply run this script in a directory containing a buildout.cfg.
The script accepts buildout command-line options, so you can
use the -c option to specify an alternate configuration file.
"""
import os
import shutil
import sys
import tempfile
from optparse import OptionParser
tmpeggs = tempfile.mkdtemp()
usage = '''\
[DESIRED PYTHON FOR BUILDOUT] bootstrap.py [options]
Bootstraps a buildout-based project.
Simply run this script in a directory containing a buildout.cfg, using the
Python that you want bin/buildout to use.
Note that by using --find-links to point to local resources, you can keep
this script from going over the network.
'''
parser = OptionParser(usage=usage)
parser.add_option("-v", "--version", help="use a specific zc.buildout version")
parser.add_option("-t", "--accept-buildout-test-releases",
dest='accept_buildout_test_releases',
action="store_true", default=False,
help=("Normally, if you do not specify a --version, the "
"bootstrap script and buildout gets the newest "
"*final* versions of zc.buildout and its recipes and "
"extensions for you. If you use this flag, "
"bootstrap and buildout will get the newest releases "
"even if they are alphas or betas."))
parser.add_option("-c", "--config-file",
help=("Specify the path to the buildout configuration "
"file to be used."))
parser.add_option("-f", "--find-links",
help=("Specify a URL to search for buildout releases"))
parser.add_option("--allow-site-packages",
action="store_true", default=False,
help=("Let bootstrap.py use existing site packages"))
parser.add_option("--setuptools-version",
help="use a specific setuptools version")
options, args = parser.parse_args()
######################################################################
# load/install setuptools
try:
if options.allow_site_packages:
import setuptools
import pkg_resources
from urllib.request import urlopen
except ImportError:
from urllib2 import urlopen
ez = {}
exec(urlopen('https://bootstrap.pypa.io/ez_setup.py').read(), ez)
if not options.allow_site_packages:
# ez_setup imports site, which adds site packages
# this will remove them from the path to ensure that incompatible versions
# of setuptools are not in the path
import site
# inside a virtualenv, there is no 'getsitepackages'.
# We can't remove these reliably
if hasattr(site, 'getsitepackages'):
for sitepackage_path in site.getsitepackages():
sys.path[:] = [x for x in sys.path if sitepackage_path not in x]
setup_args = dict(to_dir=tmpeggs, download_delay=0)
if options.setuptools_version is not None:
setup_args['version'] = options.setuptools_version
ez['use_setuptools'](**setup_args)
import setuptools
import pkg_resources
# This does not (always?) update the default working set. We will
# do it.
for path in sys.path:
if path not in pkg_resources.working_set.entries:
pkg_resources.working_set.add_entry(path)
######################################################################
# Install buildout
ws = pkg_resources.working_set
cmd = [sys.executable, '-c',
'from setuptools.command.easy_install import main; main()',
'-mZqNxd', tmpeggs]
find_links = os.environ.get(
'bootstrap-testing-find-links',
options.find_links or
('http://downloads.buildout.org/'
if options.accept_buildout_test_releases else None)
)
if find_links:
cmd.extend(['-f', find_links])
setuptools_path = ws.find(
pkg_resources.Requirement.parse('setuptools')).location
requirement = 'zc.buildout'
version = options.version
if version is None and not options.accept_buildout_test_releases:
# Figure out the most recent final version of zc.buildout.
import setuptools.package_index
_final_parts = '*final-', '*final'
def _final_version(parsed_version):
try:
return not parsed_version.is_prerelease
except AttributeError:
# Older setuptools
for part in parsed_version:
if (part[:1] == '*') and (part not in _final_parts):
return False
return True
index = setuptools.package_index.PackageIndex(
search_path=[setuptools_path])
if find_links:
index.add_find_links((find_links,))
req = pkg_resources.Requirement.parse(requirement)
if index.obtain(req) is not None:
best = []
bestv = None
for dist in index[req.project_name]:
distv = dist.parsed_version
if _final_version(distv):
if bestv is None or distv > bestv:
best = [dist]
bestv = distv
elif distv == bestv:
best.append(dist)
if best:
best.sort()
version = best[-1].version
if version:
requirement = '=='.join((requirement, version))
cmd.append(requirement)
import subprocess
if subprocess.call(cmd, env=dict(os.environ, PYTHONPATH=setuptools_path)) != 0:
raise Exception(
"Failed to execute command:\n%s" % repr(cmd)[1:-1])
######################################################################
# Import and run buildout
ws.add_entry(tmpeggs)
ws.require(requirement)
import zc.buildout.buildout
if not [a for a in args if '=' not in a]:
args.append('bootstrap')
# if -c was provided, we push it back into args for buildout' main function
if options.config_file is not None:
args[0:0] = ['-c', options.config_file]
zc.buildout.buildout.main(args)
shutil.rmtree(tmpeggs)
ZODB-5.0.0b1/buildout.cfg 0000664 0000000 0000000 00000001514 12750641745 0015021 0 ustar 00root root 0000000 0000000 [buildout]
develop = .
parts =
test
scripts
[versions]
# Avoid breakage in 4.4.5:
zope.testrunner = >= 4.4.6
[test]
recipe = zc.recipe.testrunner
eggs =
ZODB [test]
initialization =
import os, tempfile
try: os.mkdir('tmp')
except: pass
tempfile.tempdir = os.path.abspath('tmp')
defaults = ['--all']
[coverage-test]
recipe = zc.recipe.testrunner
eggs = ${test:eggs}
initialization =
import os, tempfile
try: os.mkdir('tmp')
except: pass
tempfile.tempdir = os.path.abspath('tmp')
defaults = ['--coverage', '${buildout:directory}/coverage']
[coverage-report]
recipe = zc.recipe.egg
eggs = z3c.coverage
scripts = coveragereport=coverage-report
arguments = ('${buildout:directory}/coverage',
'${buildout:directory}/coverage/report')
[scripts]
recipe = zc.recipe.egg
eggs = ${test:eggs}
interpreter = py
ZODB-5.0.0b1/doc/ 0000775 0000000 0000000 00000000000 12750641745 0013255 5 ustar 00root root 0000000 0000000 ZODB-5.0.0b1/doc/HISTORY.rst 0000664 0000000 0000000 00000030225 12750641745 0015152 0 ustar 00root root 0000000 0000000 Historical ZODB Changelog
#########################
3.10.5 (2011-11-19)
===================
Bugs Fixed
----------
- Conflict resolution failed when state included cross-database
persistent references with classes that couldn't be imported.
3.10.4 (2011-11-17)
===================
Bugs Fixed
----------
- Conflict resolution failed when state included persistent references
with classes that couldn't be imported.
3.10.3 (2011-04-12)
===================
Bugs Fixed
----------
- "activity monitor not updated for subconnections when connection
returned to pool"
https://bugs.launchpad.net/zodb/+bug/737198
- "Blob temp file get's removed before it should",
https://bugs.launchpad.net/zodb/+bug/595378
A way this to happen is that a transaction is aborted after the
commit process has started. I don't know how this would happen in
the wild.
In 3.10.3, the ZEO tpc_abort call to the server is changed to be
synchronous, which should address this case. Maybe there's another
case.
Performance enhancements
------------------------
- Improved ZEO client cache implementation to make it less likely to
evict objects that are being used.
- Small (possibly negligable) reduction in CPU in ZEO storage servers
to service object loads and in networking code.
3.10.2 (2011-02-12)
===================
Bugs Fixed
----------
- 3.10 introduced an optimization to try to address BTree conflict
errors arrising for basing BTree keys on object ids. The
optimization caused object ids allocated in aborted transactions to
be reused. Unfortunately, this optimzation led to some rather
severe failures in some applications. The symptom is a conflict
error in which one of the serials mentioned is zero. This
optimization has been removed.
See (for example): https://bugs.launchpad.net/zodb/+bug/665452
- ZEO server transaction timeouts weren't logged as critical.
https://bugs.launchpad.net/zodb/+bug/670986
3.10.1 (2010-10-27)
===================
Bugs Fixed
----------
- When a transaction rolled back a savepoint after adding objects and
subsequently added more objects and committed, an error could be
raised "ValueError: A different object already has the same oid"
causing the transaction to fail. Worse, this could leave a database
in a state where subsequent transactions in the same process would
fail.
https://bugs.launchpad.net/zodb/+bug/665452
- Unix domain sockets didn't work for ZEO (since the addition of IPv6
support). https://bugs.launchpad.net/zodb/+bug/663259
- Removed a missfeature that can cause performance problems when using
an external garbage collector with ZEO. When objects were deleted
from a storage, invalidations were sent to clients. This makes no
sense. It's wildly unlikely that the other connections/clients have
copies of the garbage. In normal storage garbage collection, we
don't send invalidations. There's no reason to send them when an
external garbage collector is used.
- ZEO client cache simulation misshandled invalidations
causing incorrect statistics and errors.
3.10.0 (2010-10-08)
===================
New Features
------------
- There are a number of performance enhancements for ZEO storage
servers.
- FileStorage indexes use a new format. They are saved and loaded much
faster and take less space. Old indexes can still be read, but new
indexes won't be readable by older versions of ZODB.
- The API for undoing multiple transactions has changed. To undo
multiple transactions in a single transaction, pass a list of
transaction identifiers to a database's undoMultiple method. Calling a
database's undo method multiple times in the same transaction now
raises an exception.
- The ZEO protocol for undo has changed. The only user-visible
consequence of this is that when ZODB 3.10 ZEO servers won't support
undo for older clients.
- The storage API (IStorage) has been tightened. Now, storages should
raise a StorageTransactionError when invalid transactions are passed
to tpc_begin, tpc_vote, or tpc_finish.
- ZEO clients (``ClientStorage`` instances) now work in forked processes,
including those created via ``multiprocessing.Process`` instances.
- Broken objects now provide the IBroken interface.
- As a convenience, you can now pass an integer port as an address to
the ZEO ClientStorage constructor.
- As a convenience, there's a new ``client`` function in the ZEO
package for constructing a ClientStorage instance. It takes the
same arguments as the ClientStorage constructor.
- DemoStorages now accept constructor athuments, close_base_on_close
and close_changes_on_close, to control whether underlying storages
are closed when the DemoStorage is closed.
https://bugs.launchpad.net/zodb/+bug/118512
- Removed the dependency on zope.proxy.
- Removed support for the _p_independent mini framework, which was
made moot by the introduction of multi-version concurrency control
several years ago.
- Added support for the transaction retry convenience
(transaction-manager attempts method) introduced in the
``transaction`` 1.1.0 release.
- Enhanced the database opening conveniences:
- You can now pass storage keyword arguments to ZODB.DB and
ZODB.connection.
- You can now pass None (rather than a storage or file name) to get
a database with a mapping storage.
- Databases now warn when committing very large records (> 16MB).
This is to try to warn people of likely design mistakes. There is a
new option (large_record_size/large-record-size) to control the
record size at which the warning is issued.
- Added support for wrapper storages that transform pickle data.
Applications for this include compression and encryption. An
example wrapper storage implementation, ZODB.tests.hexstorage, was
included for testing.
It is important that storage implementations not assume that
storages contain pickles. Renamed IStorageDB to IStorageWrapper and
expanded it to provide methods for transforming and untransforming
data records. Storages implementations should use these methods to
get pickle data from stored records.
- Deprecated ZODB.interfaces.StorageStopIteration. Storage
iterator implementations should just raise StopIteration, which
means they can now be implemented as generators.
- The filestorage packer configuration option noe accepts values of
the form ``modname:expression``, allowing the use of packer
factories with options.
- Added a new API that allows applications to make sure that current
data are read. For example, with::
self._p_jar.readCurrent(ob)
A conflict error will be raised if the version of ob read by the
transaction isn't current when the transaction is committed.
Normally, ZODB only assures that objects read are consistent, but not
necessarily up to date. Checking whether an object is up to date is
important when information read from one object is used to update
another.
BTrees are an important case of reading one object to update
another. Internal nodes are read to decide which leave notes are
updated when a BTree is updated. BTrees now use this new API to
make sure that internal nodes are up to date on updates.
- When transactions are aborted, new object ids allocated during the
transaction are saved and used in subsequent transactions. This can
help in situations where object ids are used as BTree keys and the
sequential allocation of object ids leads to conflict errors.
- ZEO servers now support a server_status method for for getting
information on the number of clients, lock requests and general
statistics.
- ZEO clients now support a client_label constructor argument and
client-label configuration-file option to specify a label for a
client in server logs. This makes it easier to identify specific
clients corresponding to server log entries, especially when there
are multiple clients originating from the same machine.
- Improved ZEO server commit lock logging. Now, locking activity is
logged at the debug level until the number of waiting lock requests
gets above 3. Log at the critical level when the number of waiting
lock requests gets above 9.
- The file-storage backup script, repozo, will now create a backup
index file if an output file name is given via the --output/-o
option.
- Added a '--kill-old-on-full' argument to the repozo backup options:
if passed, remove any older full or incremental backup files from the
repository after doing a full backup.
(https://bugs.launchpad.net/zope2/+bug/143158)
- The mkzeoinst script has been moved to a separate project:
http://pypi.python.org/pypi/zope.mkzeoinstance
and is no-longer included with ZODB.
- Removed untested unsupported dbmstorage fossile.
- ZEO servers no longer log their pids in every log message. It's just
not interesting. :)
Bugs fixed
----------
- When a pool timeout was specified for a database and old connections
were removed due to timing out, an error occured due to a bug in the
connection cleanup logic.
- When multi-database connections were no longer used and cleaned up,
their subconnections weren't cleaned up properly.
- ZEO didn't work with IPv6 addrsses.
Added IPv6 support contributed by Martin v. Loewis.
- A file storage bug could cause ZEO clients to have incorrect
information about current object revisions after reconnecting to a
database server.
- Updated the 'repozo --kill-old-on-full' option to remove any '.index'
files corresponding to backups being removed.
- ZEO extension methods failed when a client reconnected to a
storage. (https://bugs.launchpad.net/zodb/+bug/143344)
- Clarified the return Value for lastTransaction in the case when
there aren't any transactions. Now a string of 8 nulls (aka "z64")
is specified.
- Setting _p_changed on a blob wo actually writing anything caused an
error. (https://bugs.launchpad.net/zodb/+bug/440234)
- The verbose mode of the fstest was broken.
(https://bugs.launchpad.net/zodb/+bug/475996)
- Object ids created in a savepoint that is rolled back wren't being
reused. (https://bugs.launchpad.net/zodb/+bug/588389)
- Database connections didn't invalidate cache entries when conflict
errors were raised in response to checkCurrentSerialInTransaction
errors. Normally, this shouldn't be a problem, since there should be
pending invalidations for these oids which will cause the object to
be invalidated. There have been issues with ZEO persistent cache
management that have caused out of date data to remain in the cache.
(It's possible that the last of these were addressed in the
3.10.0b5.) Invalidating read data when there is a conflict error
provides some extra insurance.
- The interface, ZODB.interfaces.IStorage was incorrect. The store
method should never return a sequence of oid and serial pairs.
- When a demo storage push method was used to create a new demo
storage and the new storage was closed, the original was
(incorrectly) closed.
- There were numerous bugs in the ZEO cache tracing and analysis code.
Cache simulation, while not perfect, seems to be much more accurate
now than it was before.
The ZEO cache trace statistics and simulation scripts have been
given more descriptive names and moved to the ZEO scripts package.
- BTree sets and tree sets didn't correctly check values passed to
update or to constructors, causing Python to exit under certain
circumstances.
- Fixed bug in copying a BTrees.Length instance.
(https://bugs.launchpad.net/zodb/+bug/516653)
- Fixed a serious bug that caused cache failures when run
with Python optimization turned on.
https://bugs.launchpad.net/zodb/+bug/544305
- When using using a ClientStorage in a Storage server, there was a
threading bug that caused clients to get disconnected.
- On Mac OS X, clients that connected and disconnected quickly could
cause a ZEO server to stop accepting connections, due to a failure
to catch errors in the initial part of the connection process.
The failure to properly handle exceptions while accepting
connections is potentially problematic on other platforms.
Fixes: https://bugs.launchpad.net/zodb/+bug/135108
- Object state management wasn't done correctly when classes
implemented custom _p_deavtivate methods.
(https://bugs.launchpad.net/zodb/+bug/185066)
ZODB-5.0.0b1/doc/storage.pdf 0000664 0000000 0000000 00000061362 12750641745 0015424 0 ustar 00root root 0000000 0000000 %PDF-1.4
3 0 obj <<
/Length 1933
/Filter /FlateDecode
>>
stream
xÚÍXYÛÈ~Ÿ_¡G
9}ñÊ›íµA¼›d,ö"[Rg(RËóÚ_Ÿª®"E? ì£ú«£¿®®–\ ø#W©‚¿bU¼