revno: 4513

revision-id: nisha.gopalakrishnan@oracle.com-20120920070431-rzm71cm934l01kmo

parent: marko.makela@oracle.com-20120920060910-53jj3opi391gn2ph

committer: Nisha Gopalakrishnan <nisha.gopalakrishnan@oracle.com>

branch nick: mysql-trunk-11763447

timestamp: Thu 2012-09-20 12:34:31 +0530

message:

  BUG#11763447: 'YOU CANNOT 'ALTER' A LOG TABLE IF LOGGING IS ENABLED'  

                 EVEN IF I LOG TO FILE.

  Analysis:

  ----------

  MYSQL_UPGRADE of the master breaks the replication when

  the query logging is enabled with FILE/NONE 'log-output'

  option on the slave.

  mysql_upgrade modifies the 'general_log' and 'slow_log'

  tables after the logging is disabled as below:

  SET @old_log_state = @@global.general_log;

  SET GLOBAL general_log = 'OFF';

  ALTER TABLE general_log

  MODIFY event_time TIMESTAMP NOT NULL,

  ( .... );

  SET GLOBAL general_log = @old_log_state;

  and

  SET @old_log_state = @@global.slow_query_log;

  SET GLOBAL slow_query_log = 'OFF';

  ALTER TABLE slow_log

  MODIFY start_time TIMESTAMP NOT NULL,

  ( .... );

  SET GLOBAL slow_query_log = @old_log_state;

  In the binary log, only the ALTER statements are logged

  but not the SET statements which turns ON/OFF the logging.

  So when the slave replays the binary log,the ALTER of LOG

  tables throws an error since the logging is enabled. Also

  the 'log-output' option is not checked to determine

  whether to allow/disallow the ALTER operation.

  Fix:

  ----

  The 'log-output' option is included in the check while

  determining whether the query logging happens using the

  log tables.