Bug#36784284 - Secondary fails when executing a CREATE TABLE SELECT from an async channel

phulakun · phulakun · commit 770fa15f2f4a · 2024-07-04T07:14:28.000+02:00
Running a "CREATE TABLE ... AS SELECT" statement on a source coming
from an asynchronous channel to Group Replication, causes errors
on the replica.

Group replication uses LEX::sql_command to identify the statement
type and SELECT query block checks to identify statement as
"CREATE TABLE ... AS SELECT".

When using "CREATE TABLE ... AS SELECT" for a table with an engine
supporting Atomic DDL, the binary log on the source server will
contain the statement in the following format:

  CREATE TABLE ... START TRANSACTION
  TABLE MAP
  ROW EVENT
  ROW EVENT
  ROW EVENT
  XID / COMMIT

While committing this event (the 'CREATE TABLE ... AS SELECT' statement)
on the group replication node using the XID / COMMIT
(sql_command == SQL_END)statement, logic to identify "CREATE TABLE
... AS SELECT" fails now. This occurs because the conditions for
recognizing the statement as such are not satisfied on the replica.
As consequence, Group Replication includes inaccurate information
in the metadata associated with the event. Hence, applying event
on the secondary in the group replication fails.

To fix this issue, logic to identify "CREATE TABLE ... SELECT"
statement in Group Replication is extended to check if statement
is a transactional DDL. Flag to indicate transactional DDL is set
only while executing "CREATE TABLE ... AS SELECT" statement at
replica.

Change-Id: I19703d8d9040843e45afb031cbc6f86537741618
diff --git a/mysql-test/suite/group_replication/r/gr_create_table_as_select_from_async_replication.result b/mysql-test/suite/group_replication/r/gr_create_table_as_select_from_async_replication.result
@@ -0,0 +1,52 @@
+include/group_replication.inc [rpl_server_count=3]
+Warnings:
+Note	####	Sending passwords in plain text without SSL/TLS is extremely insecure.
+Note	####	Storing MySQL user name or password information in the connection metadata repository is not secure and is therefore not recommended. Please consider using the USER and PASSWORD connection options for START REPLICA; see the 'START REPLICA Syntax' in the MySQL Manual for more information.
+[connection server1]
+# Bug#36784284 - Secondary fails when executing a CREATE TABLE SELECT from
+#                an async channel
+
+############################################################
+#  1. Setup Group Replication on server 1 and 2.
+[connection server1]
+include/start_and_bootstrap_group_replication.inc
+[connection server2]
+include/start_group_replication.inc
+include/rpl_gr_wait_for_number_of_members.inc
+
+############################################################
+#  2. Setup a asynchronous replication connection from server 3
+#     into group (server 1)
+[connection server1]
+CHANGE REPLICATION SOURCE TO SOURCE_HOST="127.0.0.1", SOURCE_USER="root", SOURCE_PASSWORD="", SOURCE_PORT=SERVER_3_PORT, SOURCE_AUTO_POSITION=1, REQUIRE_TABLE_PRIMARY_KEY_CHECK=OFF, REQUIRE_ROW_FORMAT=1  FOR CHANNEL "";
+Warnings:
+Note	1759	Sending passwords in plain text without SSL/TLS is extremely insecure.
+Note	1760	Storing MySQL user name or password information in the connection metadata repository is not secure and is therefore not recommended. Please consider using the USER and PASSWORD connection options for START REPLICA; see the 'START REPLICA Syntax' in the MySQL Manual for more information.
+include/start_slave.inc
+
+############################################################
+#  3. Execute CREATE TABLE ... SELECT statements on server 3.
+[connection server3]
+CREATE TABLE t1 (c1 INT, c2 VARCHAR(80),PRIMARY KEY (c1));
+CREATE TABLE t2 (PRIMARY KEY (c1)) AS SELECT * FROM t1;
+INSERT INTO t1 VALUES (1, 'aaaa');
+CREATE TABLE t3 (PRIMARY KEY (c1)) AS SELECT * FROM t1;
+
+############################################################
+#  4. Wait until transactions executed on server 3 are
+#     applied on group.
+include/sync_slave_sql_with_master.inc
+[connection server3]
+include/sync_slave_sql_with_master.inc
+
+############################################################
+#  5. Cleanup
+[connection server3]
+DROP TABLE t1, t2, t3;
+include/sync_slave_sql_with_master.inc
+[connection server3]
+include/sync_slave_sql_with_master.inc
+[connection server1]
+include/stop_slave.inc
+CHANGE REPLICATION SOURCE TO SOURCE_AUTO_POSITION=0 FOR CHANNEL "";
+include/group_replication_end.inc
diff --git a/mysql-test/suite/group_replication/t/gr_create_table_as_select_from_async_replication.cnf b/mysql-test/suite/group_replication/t/gr_create_table_as_select_from_async_replication.cnf
@@ -0,0 +1,11 @@
+!include ../my.cnf
+
+[mysqld.1]
+
+[mysqld.2]
+
+[mysqld.3]
+
+[ENV]
+SERVER_MYPORT_3=                @mysqld.3.port
+SERVER_MYSOCK_3=                @mysqld.3.socket
diff --git a/mysql-test/suite/group_replication/t/gr_create_table_as_select_from_async_replication.test b/mysql-test/suite/group_replication/t/gr_create_table_as_select_from_async_replication.test
@@ -0,0 +1,94 @@
+################################################################################
+# Validate the behaviour of 'CREATE TABLE ... AS SELECT' coming from an async
+# replication channel to group replication.
+# 
+# Bug#36784284 - Secondary fails when executing a CREATE TABLE SELECT from
+#                an async channel
+#
+# 1. Setup Group Replication on server 1 and 2.
+# 2. Setup a asynchronous replication connection from server 3
+#    into group (server 1)
+# 3. Execute CREATE TABLE ... SELECT statements on server 3.
+# 4. Wait until transactions executed on server 3 are applied on group.
+#    Secondary should not fail when executing a CREATE TABLE SELECT.
+# 5. Clean-up
+################################################################################
+
+--source include/have_group_replication_plugin.inc
+--let $rpl_skip_group_replication_start= 1
+--let $rpl_server_count= 3
+--source include/group_replication.inc
+
+--echo # Bug#36784284 - Secondary fails when executing a CREATE TABLE SELECT from
+--echo #                an async channel
+
+--echo
+--echo ############################################################
+--echo #  1. Setup Group Replication on server 1 and 2.
+--let $rpl_connection_name= server1
+--source include/rpl_connection.inc
+--source include/start_and_bootstrap_group_replication.inc
+
+--let $rpl_connection_name= server2
+--source include/rpl_connection.inc
+--source include/start_group_replication.inc
+
+--let $group_replication_number_of_members= 2
+--source include/gr_wait_for_number_of_members.inc
+
+
+--echo
+--echo ############################################################
+--echo #  2. Setup a asynchronous replication connection from server 3
+--echo #     into group (server 1)
+--let $rpl_connection_name= server1
+--source include/rpl_connection.inc
+--replace_result $SERVER_MYPORT_3 SERVER_3_PORT
+--eval CHANGE REPLICATION SOURCE TO SOURCE_HOST="127.0.0.1", SOURCE_USER="root", SOURCE_PASSWORD="", SOURCE_PORT=$SERVER_MYPORT_3, SOURCE_AUTO_POSITION=1, REQUIRE_TABLE_PRIMARY_KEY_CHECK=OFF, REQUIRE_ROW_FORMAT=1  FOR CHANNEL ""
+--source include/start_slave.inc
+
+--echo
+--echo ############################################################
+--echo #  3. Execute CREATE TABLE ... SELECT statements on server 3.
+--let $rpl_connection_name= server3
+--source include/rpl_connection.inc
+
+CREATE TABLE t1 (c1 INT, c2 VARCHAR(80),PRIMARY KEY (c1));
+CREATE TABLE t2 (PRIMARY KEY (c1)) AS SELECT * FROM t1;
+
+INSERT INTO t1 VALUES (1, 'aaaa');
+CREATE TABLE t3 (PRIMARY KEY (c1)) AS SELECT * FROM t1;
+
+--echo
+--echo ############################################################
+--echo #  4. Wait until transactions executed on server 3 are
+--echo #     applied on group.
+--let $sync_slave_connection= server1
+--source include/sync_slave_sql_with_master.inc
+
+--let $rpl_connection_name= server3
+--source include/rpl_connection.inc
+--let $sync_slave_connection= server2
+--source include/sync_slave_sql_with_master.inc
+
+--echo
+--echo ############################################################
+--echo #  5. Cleanup
+--let $rpl_connection_name= server3
+--source include/rpl_connection.inc
+DROP TABLE t1, t2, t3;
+
+--let $sync_slave_connection= server1
+--source include/sync_slave_sql_with_master.inc
+
+--let $rpl_connection_name= server3
+--source include/rpl_connection.inc
+--let $sync_slave_connection= server2
+--source include/sync_slave_sql_with_master.inc
+
+--let $rpl_connection_name= server1
+--source include/rpl_connection.inc
+--source include/stop_slave.inc
+CHANGE REPLICATION SOURCE TO SOURCE_AUTO_POSITION=0 FOR CHANNEL "";
+
+--source include/group_replication_end.inc
diff --git a/sql/replication.h b/sql/replication.h
@@ -194,6 +194,18 @@ typedef struct Trans_param {
 
   /*
     Flag to identify a 'CREATE TABLE ... AS SELECT'.
+
+    'CREATE TABLE ... AS SELECT' is binlogged as
+
+      'CREATE TABLE ... START TRANSACTION'
+      'TABLE MAP'
+      'ROW EVENT'
+      'ROW EVENT'
+      ...
+      'XID / COMMIT'
+
+    At replica, flag is used to identify the 'CREATE TABLE ... START
+    TRANSACTION' block of 'CREATE TABLE ... AS SELECT' event.
   */
   bool is_create_table_as_query_block;
 } Trans_param;
diff --git a/sql/rpl_handler.cc b/sql/rpl_handler.cc
@@ -576,8 +576,9 @@ int Trans_delegate::before_commit(THD *thd, bool all,
   param.original_server_version = &(thd->variables.original_server_version);
   param.immediate_server_version = &(thd->variables.immediate_server_version);
   param.is_create_table_as_query_block =
-      (thd->lex->sql_command == SQLCOM_CREATE_TABLE &&
-       !thd->lex->query_block->field_list_is_empty());
+      ((thd->lex->sql_command == SQLCOM_CREATE_TABLE &&
+        !thd->lex->query_block->field_list_is_empty()) ||
+       thd->m_transactional_ddl.inited());
 
   bool is_real_trans =
       (all || !thd->get_transaction()->is_active(Transaction_ctx::SESSION));
