These patches provide clean signal handling and logfile rotation to Zope.

All Zope process will respond to signals in the specified manner:

  SIGHUP -  close open database connections and sockets, then restart the
            process

  SIGTERM - close open database connections and sockets, then shut down.

  SIGINT  - same as SIGTERM

  SIGUSR2 - rotate all Zope log files (z2.log, event log, detailed log)

The common idiom for doing automated logfile rotation will become:

kill -USR2 `cat /path/to/var/z2.pid`

The common idiom for doing "prophylactic" restarts will become:

kill -HUP `cat /path/to/var/z2.pid`

When a process is interrupted via ctrl-C or via a TERM signal (INT, TERM),
all open database connections and sockets will be closed before
the process dies.  This will speed up restart time for sites that
use a FileStorage as its index will be written to the filesystem before
shutdown.

Unspecified signals kill the process without doing cleanup.

ZServer/DebugLogger.py

@@ -39,12 +39,18 @@ class DebugLogger:
     """
     
     def __init__(self, filename):
+        self.filename = filename
         self.file=open(filename, 'a+b')
         l=thread.allocate_lock()
         self._acquire=l.acquire
         self._release=l.release
         self.log('U', '000000000', 'System startup')
         
+    def reopen(self):
+        self.file.close()
+        self.file=open(self.filename, 'a+b')
+        self.log('U', '000000000', 'Logfile reopened')
+
     def log(self, code, request_id, data=''):
         self._acquire()
         try:

ZServer/PubCore/ZEvent.py

@@ -15,5 +15,24 @@
 """
 
 from ZServer.medusa.thread.select_trigger import trigger
+from ZServer.medusa.asyncore import socket_map
+
+class simple_trigger(trigger):
+    def handle_close(self):
+        pass
+
+the_trigger=simple_trigger()
+
+def Wakeup(thunk=None):
+    try:
+        the_trigger.pull_trigger(thunk)
+    except OSError, why:
+        # this broken pipe as a result of perhaps a signal
+        # we want to handle this gracefully so we get rid of the old
+        # trigger and install a new one.
+        if why[0] == 32: 
+            del socket_map[the_trigger._fileno]
+            global the_trigger
+            the_trigger = simple_trigger() # adds itself back into socket_map
+            the_trigger.pull_trigger(thunk)
 
-Wakeup=trigger().pull_trigger

ZServer/medusa/asyncore.py

@@ -353,6 +353,10 @@ class dispatcher:
             if why[0] in [ECONNRESET, ENOTCONN, ESHUTDOWN]:
                 self.handle_close()
                 return ''
+            if why[0] == EAGAIN:
+                # Happens as a result of a nonfatal signal when select is
+                # interrupted
+                return ''
             else:
                 raise socket.error, why
 
@@ -524,12 +528,15 @@ if os.name == 'posix':
             # NOTE: this is a difference from the Python 2.2 library
             # version of asyncore.py. This prevents a hanging condition
             # on Linux 2.2 based systems.
-            while 1:
+            i = 0
+            while i < 5: # this is a guess
                 try:
                     return apply (os.read, (self.fd,)+args)
                 except exceptions.OSError, why:
                     if why[0] != EAGAIN:
                         raise
+                    else:
+                        i = i + 1
 
         def send (self, *args):
             return apply (os.write, (self.fd,)+args)

ZServer/medusa/http_server.py

@@ -6,7 +6,7 @@
 #						 All Rights Reserved.
 #
 
-RCS_ID =  '$Id: http_server.py,v 1.31 2002/03/21 15:48:53 htrd Exp $'
+RCS_ID =  '$Id: http_server.py,v 1.32 2002/06/11 22:02:47 chrism Exp $'
 
 # python modules
 import os
@@ -627,20 +627,26 @@ class http_server (asyncore.dispatcher):
     def handle_accept (self):
         self.total_clients.increment()
         try:
-            conn, addr = self.accept()
+            tup = self.accept()
         except socket.error:
                 # linux: on rare occasions we get a bogus socket back from
                 # accept.  socketmodule.c:makesockaddr complains that the
                 # address family is unknown.  We don't want the whole server
                 # to shut down because of this.
-            self.log_info ('warning: server accept() threw an exception', 'warning')
+            self.log_info ('warning: server accept() threw an exception',
+                           'warning')
+            self.total_clients.decrement()
             return
+        try:
+            conn, addr = tup
         except TypeError:
             # unpack non-sequence.  this can happen when a read event
             # fires on a listening socket, but when we call accept()
             # we get EWOULDBLOCK, so dispatcher.accept() returns None.
-                # Seen on FreeBSD3.
-            self.log_info ('warning: server accept() threw EWOULDBLOCK', 'warning')
+            # Seen on FreeBSD3 and Linux.
+            #self.log_info ('warning: server accept() returned %s '
+            #               '(EWOULDBLOCK?)' % tup, 'warning')
+            self.total_clients.decrement()
             return
 
         self.channel_class (self, conn, addr)

ZServer/medusa/logger.py

@@ -35,16 +35,25 @@ class file_logger:
 
         # pass this either a path or a file object.
     def __init__ (self, file, flush=1, mode='a'):
+
+        self.filename = None
+
         if type(file) == type(''):
             if (file == '-'):
                 import sys
                 self.file = sys.stdout
             else:
+                self.filename = file
                 self.file = open (file, mode)
         else:
             self.file = file
         self.do_flush = flush
         
+    def reopen(self):
+        if self.filename:
+            self.file.close()
+            self.file = open(self.filename,'a')            
+
     def __repr__ (self):
         return '<file logger: %s>' % self.file
         

lib/python/ZServer/DebugLogger.py

@@ -39,12 +39,18 @@ class DebugLogger:
     """
     
     def __init__(self, filename):
+        self.filename = filename
         self.file=open(filename, 'a+b')
         l=thread.allocate_lock()
         self._acquire=l.acquire
         self._release=l.release
         self.log('U', '000000000', 'System startup')
         
+    def reopen(self):
+        self.file.close()
+        self.file=open(self.filename, 'a+b')
+        self.log('U', '000000000', 'Logfile reopened')
+
     def log(self, code, request_id, data=''):
         self._acquire()
         try:

lib/python/ZServer/PubCore/ZEvent.py

@@ -15,5 +15,24 @@
 """
 
 from ZServer.medusa.thread.select_trigger import trigger
+from ZServer.medusa.asyncore import socket_map
+
+class simple_trigger(trigger):
+    def handle_close(self):
+        pass
+
+the_trigger=simple_trigger()
+
+def Wakeup(thunk=None):
+    try:
+        the_trigger.pull_trigger(thunk)
+    except OSError, why:
+        # this broken pipe as a result of perhaps a signal
+        # we want to handle this gracefully so we get rid of the old
+        # trigger and install a new one.
+        if why[0] == 32: 
+            del socket_map[the_trigger._fileno]
+            global the_trigger
+            the_trigger = simple_trigger() # adds itself back into socket_map
+            the_trigger.pull_trigger(thunk)
 
-Wakeup=trigger().pull_trigger

lib/python/ZServer/medusa/asyncore.py

@@ -353,6 +353,10 @@ class dispatcher:
             if why[0] in [ECONNRESET, ENOTCONN, ESHUTDOWN]:
                 self.handle_close()
                 return ''
+            if why[0] == EAGAIN:
+                # Happens as a result of a nonfatal signal when select is
+                # interrupted
+                return ''
             else:
                 raise socket.error, why
 
@@ -524,12 +528,15 @@ if os.name == 'posix':
             # NOTE: this is a difference from the Python 2.2 library
             # version of asyncore.py. This prevents a hanging condition
             # on Linux 2.2 based systems.
-            while 1:
+            i = 0
+            while i < 5: # this is a guess
                 try:
                     return apply (os.read, (self.fd,)+args)
                 except exceptions.OSError, why:
                     if why[0] != EAGAIN:
                         raise
+                    else:
+                        i = i + 1
 
         def send (self, *args):
             return apply (os.write, (self.fd,)+args)

lib/python/ZServer/medusa/http_server.py

@@ -6,7 +6,7 @@
 #						 All Rights Reserved.
 #
 
-RCS_ID =  '$Id: http_server.py,v 1.31 2002/03/21 15:48:53 htrd Exp $'
+RCS_ID =  '$Id: http_server.py,v 1.32 2002/06/11 22:02:47 chrism Exp $'
 
 # python modules
 import os
@@ -627,20 +627,26 @@ class http_server (asyncore.dispatcher):
     def handle_accept (self):
         self.total_clients.increment()
         try:
-            conn, addr = self.accept()
+            tup = self.accept()
         except socket.error:
                 # linux: on rare occasions we get a bogus socket back from
                 # accept.  socketmodule.c:makesockaddr complains that the
                 # address family is unknown.  We don't want the whole server
                 # to shut down because of this.
-            self.log_info ('warning: server accept() threw an exception', 'warning')
+            self.log_info ('warning: server accept() threw an exception',
+                           'warning')
+            self.total_clients.decrement()
             return
+        try:
+            conn, addr = tup
         except TypeError:
             # unpack non-sequence.  this can happen when a read event
             # fires on a listening socket, but when we call accept()
             # we get EWOULDBLOCK, so dispatcher.accept() returns None.
-                # Seen on FreeBSD3.
-            self.log_info ('warning: server accept() threw EWOULDBLOCK', 'warning')
+            # Seen on FreeBSD3 and Linux.
+            #self.log_info ('warning: server accept() returned %s '
+            #               '(EWOULDBLOCK?)' % tup, 'warning')
+            self.total_clients.decrement()
             return
 
         self.channel_class (self, conn, addr)

lib/python/ZServer/medusa/logger.py

@@ -35,16 +35,25 @@ class file_logger:
 
         # pass this either a path or a file object.
     def __init__ (self, file, flush=1, mode='a'):
+
+        self.filename = None
+
         if type(file) == type(''):
             if (file == '-'):
                 import sys
                 self.file = sys.stdout
             else:
+                self.filename = file
                 self.file = open (file, mode)
         else:
             self.file = file
         self.do_flush = flush
         
+    def reopen(self):
+        if self.filename:
+            self.file.close()
+            self.file = open(self.filename,'a')            
+
     def __repr__ (self):
         return '<file logger: %s>' % self.file
         

z2.py

@@ -253,6 +253,75 @@ program=sys.argv[0]
 here=os.path.join(os.getcwd(), os.path.split(program)[0])
 Zpid=''
 
+
+#   Install signal handlers.
+#   SIGTERM - cleanly shuts down.
+#   SIGHUP - cleanly restarts.
+#   SIGUSR2 - open and close all log files (for log rotation)
+
+if os.name == 'posix':  # signal.signal() not reliable on Windows
+    import signal
+    def closeall():
+        zLOG.LOG('Z2', zLOG.INFO, "Closing all open network connections")
+        for socket in asyncore.socket_map.values():
+            try:
+                socket.close()
+            except:
+                pass
+
+        zLOG.LOG('Z2', zLOG.INFO, "Closing all open ZODB databases")
+        import Globals
+        for db in Globals.opened:
+            try:
+                db.close()
+            finally:
+                pass
+
+    def sighandler(signum, frame):
+        signame = zdaemon.Daemon.get_signal_name(signum)
+        zLOG.LOG('Z2', zLOG.INFO , "Caught signal %s" % signame)
+
+        if signum in [signal.SIGTERM, signal.SIGINT]:
+            closeall()
+            zLOG.LOG('Z2', zLOG.INFO , "Shutting down")
+            sys.exit(0)
+
+        if signum == signal.SIGHUP:
+            closeall()
+            zLOG.LOG('Z2', zLOG.INFO , "Restarting")
+            sys.exit(1)
+
+        if signum == signal.SIGUSR2:
+            zLOG.LOG('Z2', zLOG.INFO , "Reopening log files")
+            if hasattr(sys, '__lg') and hasattr(sys.__lg, 'reopen'):
+                sys.__lg.reopen()
+                zLOG.LOG('Z2', zLOG.BLATHER, "Reopened Z2.log")
+            if (hasattr(sys, '__detailedlog') and
+                hasattr(sys.__detailedlog, 'reopen')):
+                zLOG.LOG('Z2', zLOG.BLATHER,"Reopened detailed request log")
+                sys.__detailedlog.reopen()
+            if hasattr(zLOG, '_set_stupid_dest'):
+                zLOG._set_stupid_dest(None)
+            else:
+                zLOG._stupid_dest = None
+            ZLogger.stupidFileLogger._stupid_dest = None
+            zLOG.LOG('Z2', zLOG.BLATHER, "Reopened event log")
+            zLOG.LOG('Z2', zLOG.INFO, "Log files reopened successfully")
+        
+    INTERESTING_SIGNALS = {
+        signal.SIGTERM: sighandler,
+        signal.SIGHUP: sighandler,
+        signal.SIGUSR2: sighandler,
+        signal.SIGINT: sighandler,
+        }
+
+    def installsighandlers():
+        # normal kill, restart, and open&close logs respectively
+        for signum, sighandler in INTERESTING_SIGNALS.items():
+            signal.signal(signum, sighandler)
+            signame = zdaemon.Daemon.get_signal_name(signum)
+            zLOG.LOG('Z2',zLOG.BLATHER,"Installed sighandler for %s" % signame)
+
 ########################################################################
 # Configuration section
 
@@ -510,7 +579,8 @@ if Zpid and not READ_ONLY:
     import zdaemon, App.FindHomes, posix
     sys.ZMANAGED=1
     
-    zdaemon.run(sys.argv, os.path.join(CLIENT_HOME, Zpid))
+    zdaemon.run(sys.argv, os.path.join(CLIENT_HOME, Zpid),
+                INTERESTING_SIGNALS.keys())
 
 os.chdir(CLIENT_HOME)
 
@@ -535,7 +605,12 @@ try:
     if DETAILED_LOG_FILE:
         from ZServer import DebugLogger
         logfile=os.path.join(CLIENT_HOME, DETAILED_LOG_FILE)
-        DebugLogger.log=DebugLogger.DebugLogger(logfile).log
+        zLOG.LOG('z2', zLOG.BLATHER,
+                 'Using detailed request log file %s' % logfile)
+        DL=DebugLogger.DebugLogger(logfile)
+        DebugLogger.log=DL.log
+        DebugLogger.reopen=DL.reopen
+        sys.__detailedlog=DL
 
     # Import Zope (or Main)
     exec "import "+MODULE in {}
@@ -579,16 +654,21 @@ try:
 
     if READ_ONLY:
         lg = logger.file_logger('-') # log to stdout
+        zLOG.LOG('z2', zLOG.BLATHER, 'Logging access log to stdout')
     elif os.environ.has_key('ZSYSLOG_ACCESS'):
         if os.environ.has_key("ZSYSLOG_ACCESS_FACILITY"):
             lg = logger.syslog_logger(os.environ['ZSYSLOG_ACCESS'],facility=os.environ['ZSYSLOG_ACCESS_FACILITY'])
         else:
             lg = logger.syslog_logger(os.environ['ZSYSLOG_ACCESS'])
+        zLOG.LOG('z2', zLOG.BLATHER, 'Using local syslog access log')
     elif os.environ.has_key('ZSYSLOG_ACCESS_SERVER'):
         (addr, port) = os.environ['ZSYSLOG_ACCESS_SERVER'].split( ':')
         lg = logger.syslog_logger((addr, int(port)))
+        zLOG.LOG('z2', zLOG.BLATHER, 'Using remote syslog access log')
     else:
         lg = logger.file_logger(LOG_PATH)
+        zLOG.LOG('z2', zLOG.BLATHER, 'Using access log file %s' % LOG_PATH)
+    sys.__lg = lg
 
     # HTTP Server
     if HTTP_PORT:
@@ -786,7 +866,7 @@ try:
     except:
         raise
 
-    # Check umask sanity.
+    # Check umask sanity and install signal handlers if we're on posix.
     if os.name == 'posix':
         # umask is silly, blame POSIX.  We have to set it to get its value.
         current_umask = os.umask(0)
@@ -796,6 +876,8 @@ try:
             zLOG.LOG("z2", zLOG.INFO, 'Your umask of ' + current_umask + \
                      ' may be too permissive; for the security of your ' + \
                      'Zope data, it is recommended you use 077')
+        # we've deferred til now to actuall install signal handlers
+        installsighandlers()
 
 except:
     # Log startup exception and tell zdaemon not to restart us.