BUG#26257 New Federated Server Functionality Doesn't support differently named tables

* Modified Federated memory allocation to use MEM_ROOT
* Modified sql_servers and federated to allocate share connection
  parameters to use MEM_ROOT
* Modified Federated to allow tablename in addition to server name
* Implicit flushing of tables using altered/dropped server name
* Added tests to prove new functionality works

Contributors to this patch: Patrick Galbraith, Antony Curtis

mysql-test/r/federated_server.result

@@ -20,6 +20,14 @@ CREATE TABLE first_db.t1 (
 `name` varchar(64) NOT NULL default ''
     )
 DEFAULT CHARSET=latin1;
+DROP TABLE IF EXISTS first_db.t2;
+Warnings:
+Note	1051	Unknown table 't2'
+CREATE TABLE first_db.t2 (
+`id` int(20) NOT NULL,
+`name` varchar(64) NOT NULL default ''
+    )
+DEFAULT CHARSET=latin1;
 use second_db;
 DROP TABLE IF EXISTS second_db.t1;
 Warnings:
@@ -29,6 +37,14 @@ CREATE TABLE second_db.t1 (
 `name` varchar(64) NOT NULL default ''
     )
 DEFAULT CHARSET=latin1;
+DROP TABLE IF EXISTS second_db.t2;
+Warnings:
+Note	1051	Unknown table 't2'
+CREATE TABLE second_db.t2 (
+`id` int(20) NOT NULL,
+`name` varchar(64) NOT NULL default ''
+    )
+DEFAULT CHARSET=latin1;
 drop server if exists 'server_one';
 create server 'server_one' foreign data wrapper 'mysql' options
 (HOST '127.0.0.1',
@@ -60,10 +76,10 @@ CREATE TABLE federated.old (
     )
 ENGINE="FEDERATED" DEFAULT CHARSET=latin1
 CONNECTION='mysql://root@127.0.0.1:SLAVE_PORT/first_db/t1';
-INSERT INTO federated.old (id, name) values (1, 'federated.old url');
+INSERT INTO federated.old (id, name) values (1, 'federated.old-> first_db.t1, url format');
 SELECT * FROM federated.old;
 id	name
-1	federated.old url
+1	federated.old-> first_db.t1, url format
 DROP TABLE IF EXISTS federated.old2;
 Warnings:
 Note	1051	Unknown table 'old2'
@@ -72,8 +88,37 @@ CREATE TABLE federated.old2 (
 `name` varchar(64) NOT NULL default ''
     )
 ENGINE="FEDERATED" DEFAULT CHARSET=latin1
+CONNECTION='mysql://root@127.0.0.1:SLAVE_PORT/first_db/t2';
+INSERT INTO federated.old2 (id, name) values (1, 'federated.old2-> first_db.t2, url format');
+SELECT * FROM federated.old2;
+id	name
+1	federated.old2-> first_db.t2, url format
+DROP TABLE IF EXISTS federated.urldb2t1;
+Warnings:
+Note	1051	Unknown table 'urldb2t1'
+CREATE TABLE federated.urldb2t1 (
+`id` int(20) NOT NULL,
+`name` varchar(64) NOT NULL default ''
+    )
+ENGINE="FEDERATED" DEFAULT CHARSET=latin1
 CONNECTION='mysql://root@127.0.0.1:SLAVE_PORT/second_db/t1';
-INSERT INTO federated.old2 (id, name) values (1, 'federated.old2 url');
+INSERT INTO federated.urldb2t1 (id, name) values (1, 'federated.urldb2t1 -> second_db.t1, url format');
+SELECT * FROM federated.urldb2t1;
+id	name
+1	federated.urldb2t1 -> second_db.t1, url format
+DROP TABLE IF EXISTS federated.urldb2t2;
+Warnings:
+Note	1051	Unknown table 'urldb2t2'
+CREATE TABLE federated.urldb2t2 (
+`id` int(20) NOT NULL,
+`name` varchar(64) NOT NULL default ''
+    )
+ENGINE="FEDERATED" DEFAULT CHARSET=latin1
+CONNECTION='mysql://root@127.0.0.1:SLAVE_PORT/second_db/t2';
+INSERT INTO federated.urldb2t2 (id, name) values (1, 'federated.urldb2t2 -> second_db.t2, url format');
+SELECT * FROM federated.urldb2t2;
+id	name
+1	federated.urldb2t2 -> second_db.t2, url format
 DROP TABLE IF EXISTS federated.t1;
 Warnings:
 Note	1051	Unknown table 't1'
@@ -83,18 +128,38 @@ CREATE TABLE federated.t1 (
     )
 ENGINE="FEDERATED" DEFAULT CHARSET=latin1
 CONNECTION='server_one';
-INSERT INTO federated.t1 (id, name) values (1, 'server_one, new scheme');
+INSERT INTO federated.t1 (id, name) values (1, 'server_one, new scheme, first_db.t1');
 SELECT * FROM federated.t1;
 id	name
-1	federated.old url
-1	server_one, new scheme
+1	federated.old-> first_db.t1, url format
+1	server_one, new scheme, first_db.t1
+DROP TABLE IF EXISTS federated.whatever;
+Warnings:
+Note	1051	Unknown table 'whatever'
+CREATE TABLE federated.whatever (
+`id` int(20) NOT NULL,
+`name` varchar(64) NOT NULL default ''
+    )
+ENGINE="FEDERATED" DEFAULT CHARSET=latin1
+CONNECTION='server_one/t1';
+INSERT INTO federated.whatever (id, name) values (1, 'server_one, new scheme, whatever, first_db.t1');
+SELECT * FROM federated.whatever;
+id	name
+1	federated.old-> first_db.t1, url format
+1	server_one, new scheme, first_db.t1
+1	server_one, new scheme, whatever, first_db.t1
 ALTER SERVER 'server_one' options(DATABASE 'second_db');
-flush tables;
-INSERT INTO federated.t1 (id, name) values (1, 'server_two, new scheme');
+INSERT INTO federated.t1 (id, name) values (1, 'server_two, new scheme, second_db.t1');
 SELECT * FROM federated.t1;
 id	name
-1	federated.old2 url
-1	server_two, new scheme
+1	federated.urldb2t1 -> second_db.t1, url format
+1	server_two, new scheme, second_db.t1
+INSERT INTO federated.whatever (id, name) values (1, 'server_two, new scheme, whatever, second_db.t1');
+SELECT * FROM federated.whatever;
+id	name
+1	federated.urldb2t1 -> second_db.t1, url format
+1	server_two, new scheme, second_db.t1
+1	server_two, new scheme, whatever, second_db.t1
 drop table federated.t1;
 drop server 'server_one';
 drop server 'server_two';

mysql-test/t/federated_server.test

@@ -17,6 +17,13 @@ CREATE TABLE first_db.t1 (
     )
   DEFAULT CHARSET=latin1;
 
+DROP TABLE IF EXISTS first_db.t2;
+CREATE TABLE first_db.t2 (
+    `id` int(20) NOT NULL,
+    `name` varchar(64) NOT NULL default ''
+    )
+  DEFAULT CHARSET=latin1;
+
 use second_db;
 DROP TABLE IF EXISTS second_db.t1;
 CREATE TABLE second_db.t1 (
@@ -25,6 +32,13 @@ CREATE TABLE second_db.t1 (
     )
   DEFAULT CHARSET=latin1;
 
+DROP TABLE IF EXISTS second_db.t2;
+CREATE TABLE second_db.t2 (
+    `id` int(20) NOT NULL,
+    `name` varchar(64) NOT NULL default ''
+    )
+  DEFAULT CHARSET=latin1;
+
 connection master;
 
 drop server if exists 'server_one';
@@ -61,7 +75,7 @@ eval CREATE TABLE federated.old (
   ENGINE="FEDERATED" DEFAULT CHARSET=latin1
   CONNECTION='mysql://root@127.0.0.1:$SLAVE_MYPORT/first_db/t1';
 
-INSERT INTO federated.old (id, name) values (1, 'federated.old url');
+INSERT INTO federated.old (id, name) values (1, 'federated.old-> first_db.t1, url format');
 
 SELECT * FROM federated.old;
 
@@ -72,9 +86,32 @@ eval CREATE TABLE federated.old2 (
     `name` varchar(64) NOT NULL default ''
     )
   ENGINE="FEDERATED" DEFAULT CHARSET=latin1
+  CONNECTION='mysql://root@127.0.0.1:$SLAVE_MYPORT/first_db/t2';
+
+INSERT INTO federated.old2 (id, name) values (1, 'federated.old2-> first_db.t2, url format');
+SELECT * FROM federated.old2;
+
+DROP TABLE IF EXISTS federated.urldb2t1;
+--replace_result $SLAVE_MYPORT SLAVE_PORT
+eval CREATE TABLE federated.urldb2t1 (
+    `id` int(20) NOT NULL,
+    `name` varchar(64) NOT NULL default ''
+    )
+  ENGINE="FEDERATED" DEFAULT CHARSET=latin1
   CONNECTION='mysql://root@127.0.0.1:$SLAVE_MYPORT/second_db/t1';
+INSERT INTO federated.urldb2t1 (id, name) values (1, 'federated.urldb2t1 -> second_db.t1, url format');
+SELECT * FROM federated.urldb2t1;
 
-INSERT INTO federated.old2 (id, name) values (1, 'federated.old2 url');
+DROP TABLE IF EXISTS federated.urldb2t2;
+--replace_result $SLAVE_MYPORT SLAVE_PORT
+eval CREATE TABLE federated.urldb2t2 (
+    `id` int(20) NOT NULL,
+    `name` varchar(64) NOT NULL default ''
+    )
+  ENGINE="FEDERATED" DEFAULT CHARSET=latin1
+  CONNECTION='mysql://root@127.0.0.1:$SLAVE_MYPORT/second_db/t2';
+INSERT INTO federated.urldb2t2 (id, name) values (1, 'federated.urldb2t2 -> second_db.t2, url format');
+SELECT * FROM federated.urldb2t2;
 
 DROP TABLE IF EXISTS federated.t1;
 CREATE TABLE federated.t1 (
@@ -84,17 +121,30 @@ CREATE TABLE federated.t1 (
   ENGINE="FEDERATED" DEFAULT CHARSET=latin1
   CONNECTION='server_one';
 
-INSERT INTO federated.t1 (id, name) values (1, 'server_one, new scheme');
+INSERT INTO federated.t1 (id, name) values (1, 'server_one, new scheme, first_db.t1');
 
 SELECT * FROM federated.t1;
 
+DROP TABLE IF EXISTS federated.whatever;
+CREATE TABLE federated.whatever (
+    `id` int(20) NOT NULL,
+    `name` varchar(64) NOT NULL default ''
+    )
+  ENGINE="FEDERATED" DEFAULT CHARSET=latin1
+  CONNECTION='server_one/t1';
+INSERT INTO federated.whatever (id, name) values (1, 'server_one, new scheme, whatever, first_db.t1');
+SELECT * FROM federated.whatever;
+
 ALTER SERVER 'server_one' options(DATABASE 'second_db');
 
-flush tables;
+# FLUSH TABLES is now unneccessary
 
-INSERT INTO federated.t1 (id, name) values (1, 'server_two, new scheme');
+INSERT INTO federated.t1 (id, name) values (1, 'server_two, new scheme, second_db.t1');
 SELECT * FROM federated.t1;
 
+INSERT INTO federated.whatever (id, name) values (1, 'server_two, new scheme, whatever, second_db.t1');
+SELECT * FROM federated.whatever;
+
 drop table federated.t1;
 
 drop server 'server_one';

sql/mysql_priv.h

@@ -1430,6 +1430,9 @@ void close_open_tables_and_downgrade(ALTER_PARTITION_PARAM_TYPE *lpt);
 void mysql_wait_completed_table(ALTER_PARTITION_PARAM_TYPE *lpt, TABLE *my_table);
 
 bool close_cached_tables(THD *thd, bool wait_for_refresh, TABLE_LIST *tables, bool have_lock = FALSE);
+bool close_cached_connection_tables(THD *thd, bool wait_for_refresh,
+                                    LEX_STRING *connect_string,
+                                    bool have_lock = FALSE);
 void copy_field_from_tmp_record(Field *field,int offset);
 bool fill_record(THD *thd, Field **field, List<Item> &values,
                  bool ignore_errors);

sql/sql_base.cc

@@ -858,6 +858,7 @@ void free_io_cache(TABLE *table)
   DBUG_VOID_RETURN;
 }
 
+
 /*
   Close all tables which aren't in use by any thread
 
@@ -969,6 +970,71 @@ bool close_cached_tables(THD *thd, bool if_wait_for_refresh,
 }
 
 
+/*
+  Close all tables which match specified connection string or
+  if specified string is NULL, then any table with a connection string.
+*/
+
+bool close_cached_connection_tables(THD *thd, bool if_wait_for_refresh,
+                                    LEX_STRING *connection, bool have_lock)
+{
+  uint idx;
+  TABLE_LIST tmp, *tables= NULL;
+  bool result= FALSE;
+  DBUG_ENTER("close_cached_connections");
+  DBUG_ASSERT(thd);
+
+  bzero(&tmp, sizeof(TABLE_LIST));
+  
+  if (!have_lock)
+    VOID(pthread_mutex_lock(&LOCK_open));
+  
+  for (idx= 0; idx < table_def_cache.records; idx++)
+  {
+    TABLE_SHARE *share= (TABLE_SHARE *) hash_element(&table_def_cache, idx);
+
+    /* Ignore if table is not open or does not have a connect_string */
+    if (!share->connect_string.length || !share->ref_count)
+      continue;
+
+    /* Compare the connection string */
+    if (connection &&
+        (connection->length > share->connect_string.length ||
+         (connection->length < share->connect_string.length &&
+          (share->connect_string.str[connection->length] != '/' &&
+           share->connect_string.str[connection->length] != '\\')) ||
+         strncasecmp(connection->str, share->connect_string.str,
+                     connection->length)))
+      continue;
+
+    /* close_cached_tables() only uses these elements */
+    tmp.db= share->db.str;
+    tmp.table_name= share->table_name.str;
+    tmp.next_local= tables;
+
+    tables= (TABLE_LIST *) memdup_root(thd->mem_root, (char*)&tmp, 
+                                       sizeof(TABLE_LIST));
+  }
+
+  if (tables)
+    result= close_cached_tables(thd, FALSE, tables, TRUE);
+  
+  if (!have_lock)
+    VOID(pthread_mutex_unlock(&LOCK_open));
+  
+  if (if_wait_for_refresh)
+  {
+    pthread_mutex_lock(&thd->mysys_var->mutex);
+    thd->mysys_var->current_mutex= 0;
+    thd->mysys_var->current_cond= 0;
+    thd->proc_info=0;
+    pthread_mutex_unlock(&thd->mysys_var->mutex);
+  }
+
+  DBUG_RETURN(result);
+}
+
+
 /*
   Mark all tables in the list which were used by current substatement
   as free for reuse.

sql/sql_servers.cc

@@ -16,6 +16,21 @@
 
 /*
   The servers are saved in the system table "servers"
+  
+  Currently, when the user performs an ALTER SERVER or a DROP SERVER
+  operation, it will cause all open tables which refer to the named
+  server connection to be flushed. This may cause some undesirable
+  behaviour with regard to currently running transactions. It is 
+  expected that the DBA knows what s/he is doing when s/he performs
+  the ALTER SERVER or DROP SERVER operation.
+  
+  TODO:
+  It is desirable for us to implement a callback mechanism instead where
+  callbacks can be registered for specific server protocols. The callback
+  will be fired when such a server name has been created/altered/dropped
+  or when statistics are to be gathered such as how many actual connections.
+  Storage engines etc will be able to make use of the callback so that
+  currently running transactions etc will not be disrupted.
 */
 
 #include "mysql_priv.h"
@@ -557,6 +572,8 @@ int drop_server(THD *thd, LEX_SERVER_OPTIONS *server_options)
   int error;
   TABLE_LIST tables;
   TABLE *table;
+  LEX_STRING name= { server_options->server_name, 
+                     server_options->server_name_length };
 
   DBUG_ENTER("drop_server");
   DBUG_PRINT("info", ("server name server->server_name %s",
@@ -578,14 +595,16 @@ int drop_server(THD *thd, LEX_SERVER_OPTIONS *server_options)
     goto end;
   }
 
-  error= delete_server_record(table,
-                              server_options->server_name,
-                              server_options->server_name_length);
+  error= delete_server_record(table, name.str, name.length);
 
-  /*
-	Perform a reload so we don't have a 'hole' in our mem_root
-  */
-  servers_load(thd, &tables);
+  /* close the servers table before we call closed_cached_connection_tables */
+  close_thread_tables(thd);
+
+  if (close_cached_connection_tables(thd, TRUE, &name))
+  {
+    push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+                        ER_UNKNOWN_ERROR, "Server connection in use");
+  }
 
 end:
   rw_unlock(&THR_LOCK_servers);
@@ -975,6 +994,8 @@ int alter_server(THD *thd, LEX_SERVER_OPTIONS *server_options)
 {
   int error= ER_FOREIGN_SERVER_DOESNT_EXIST;
   FOREIGN_SERVER *altered, *existing;
+  LEX_STRING name= { server_options->server_name, 
+                     server_options->server_name_length };
   DBUG_ENTER("alter_server");
   DBUG_PRINT("info", ("server_options->server_name %s",
                       server_options->server_name));
@@ -982,8 +1003,8 @@ int alter_server(THD *thd, LEX_SERVER_OPTIONS *server_options)
   rw_wrlock(&THR_LOCK_servers);
 
   if (!(existing= (FOREIGN_SERVER *) hash_search(&servers_cache,
-                                                 (byte*) server_options->server_name,
-                                               server_options->server_name_length)))
+                                                 (byte*) name.str,
+                                                 name.length)))
     goto end;
 
   altered= (FOREIGN_SERVER *)alloc_root(&mem,
@@ -993,6 +1014,15 @@ int alter_server(THD *thd, LEX_SERVER_OPTIONS *server_options)
 
   error= update_server(thd, existing, altered);
 
+  /* close the servers table before we call closed_cached_connection_tables */
+  close_thread_tables(thd);
+
+  if (close_cached_connection_tables(thd, FALSE, &name))
+  {
+    push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+                        ER_UNKNOWN_ERROR, "Server connection in use");
+  }
+
 end:
   DBUG_PRINT("info", ("error returned %d", error));
   rw_unlock(&THR_LOCK_servers);
@@ -1143,6 +1173,12 @@ void servers_free(bool end)
   DBUG_ENTER("servers_free");
   if (!hash_inited(&servers_cache))
     DBUG_VOID_RETURN;
+  if (!end)
+  {
+    free_root(&mem, MYF(MY_MARK_BLOCKS_FREE));
+	my_hash_reset(&servers_cache);
+    DBUG_VOID_RETURN;
+  }
   rwlock_destroy(&THR_LOCK_servers);
   free_root(&mem,MYF(0));
   hash_free(&servers_cache);
@@ -1150,6 +1186,51 @@ void servers_free(bool end)
 }
 
 
+/*
+  SYNOPSIS
+
+  clone_server(MEM_ROOT *mem_root, FOREIGN_SERVER *orig, FOREIGN_SERVER *buff)
+
+  Create a clone of FOREIGN_SERVER. If the supplied mem_root is of
+  thd->mem_root then the copy is automatically disposed at end of statement.
+
+  NOTES
+
+  ARGS
+   MEM_ROOT pointer (strings are copied into this mem root) 
+   FOREIGN_SERVER pointer (made a copy of)
+   FOREIGN_SERVER buffer (if not-NULL, this pointer is returned)
+
+  RETURN VALUE
+   FOREIGN_SEVER pointer (copy of one supplied FOREIGN_SERVER)
+*/
+
+static FOREIGN_SERVER *clone_server(MEM_ROOT *mem, const FOREIGN_SERVER *server,
+                                    FOREIGN_SERVER *buffer)
+{
+  DBUG_ENTER("sql_server.cc:clone_server");
+
+  if (!buffer)
+    buffer= (FOREIGN_SERVER *) alloc_root(mem, sizeof(FOREIGN_SERVER));
+
+  buffer->server_name= strmake_root(mem, server->server_name,
+                                    server->server_name_length);
+  buffer->port= server->port;
+  buffer->server_name_length= server->server_name_length;
+  
+  /* TODO: We need to examine which of these can really be NULL */
+  buffer->db= server->db ? strdup_root(mem, server->db) : NULL;
+  buffer->scheme= server->scheme ? strdup_root(mem, server->scheme) : NULL;
+  buffer->username= server->username? strdup_root(mem, server->username): NULL;
+  buffer->password= server->password? strdup_root(mem, server->password): NULL;
+  buffer->socket= server->socket ? strdup_root(mem, server->socket) : NULL;
+  buffer->owner= server->owner ? strdup_root(mem, server->owner) : NULL;
+  buffer->host= server->host ? strdup_root(mem, server->host) : NULL;
+
+ DBUG_RETURN(buffer);
+}
+
+
 /*
 
   SYNOPSIS
@@ -1163,11 +1244,11 @@ void servers_free(bool end)
 
 */
 
-FOREIGN_SERVER *get_server_by_name(const char *server_name)
+FOREIGN_SERVER *get_server_by_name(MEM_ROOT *mem, const char *server_name,
+                                   FOREIGN_SERVER *buff)
 {
-  ulong error_num=0;
   uint server_name_length;
-  FOREIGN_SERVER *server= 0;
+  FOREIGN_SERVER *server;
   DBUG_ENTER("get_server_by_name");
   DBUG_PRINT("info", ("server_name %s", server_name));
 
@@ -1176,7 +1257,6 @@ FOREIGN_SERVER *get_server_by_name(const char *server_name)
   if (! server_name || !strlen(server_name))
   {
     DBUG_PRINT("info", ("server_name not defined!"));
-    error_num= 1;
     DBUG_RETURN((FOREIGN_SERVER *)NULL);
   }
 
@@ -1190,6 +1270,10 @@ FOREIGN_SERVER *get_server_by_name(const char *server_name)
                         server_name, server_name_length));
     server= (FOREIGN_SERVER *) NULL;
   }
+  /* otherwise, make copy of server */
+  else
+    server= clone_server(mem, server, buff);
+
   DBUG_PRINT("info", ("unlocking servers_cache"));
   rw_unlock(&THR_LOCK_servers);
   DBUG_RETURN(server);

sql/sql_servers.h

@@ -39,4 +39,5 @@ int drop_server(THD *thd, LEX_SERVER_OPTIONS *server_options);
 int alter_server(THD *thd, LEX_SERVER_OPTIONS *server_options);
 
 /* lookup functions */
-FOREIGN_SERVER *get_server_by_name(const char *server_name);
+FOREIGN_SERVER *get_server_by_name(MEM_ROOT *mem, const char *server_name,
+                                   FOREIGN_SERVER *server_buffer);

storage/federated/ha_federated.h

@@ -43,6 +43,8 @@
   The example implements the minimum of what you will probably need.
 */
 typedef struct st_federated_share {
+  MEM_ROOT mem_root;
+
   bool parsed;
   /* this key is unique db/tablename */
   const char *share_key;
@@ -67,6 +69,7 @@ typedef struct st_federated_share {
   char *sport;
   int share_key_length;
   ushort port;
+
   uint table_name_length, server_name_length, connect_string_length, use_count;
   pthread_mutex_t mutex;
   THR_LOCK lock;