From d0150dc14e11f2e0b7ad60b9db40bd65e82e917e Mon Sep 17 00:00:00 2001 From: Vlad Lesin Date: Mon, 27 Apr 2020 21:46:05 +0300 Subject: MDEV-20230: mariabackup --ftwrl-wait-timeout never times out on explicit lock --ftwrl-wait-timeout does not finish mariabackup execution when acquired backup lock can't be grabbed for the certain amount of time, it just waits for a long queries finishing before acquiring the lock to avoid unnecessary locking. This commit extends --ftwrl-wait-timeout so, that mariabackup execution is finished if it waits for backup lock during certain amount of time. --- extra/mariabackup/backup_mysql.cc | 124 +++++++++++++++++++++----------------- 1 file changed, 69 insertions(+), 55 deletions(-) (limited to 'extra/mariabackup/backup_mysql.cc') diff --git a/extra/mariabackup/backup_mysql.cc b/extra/mariabackup/backup_mysql.cc index d5d0c90376e..171c4407ed5 100644 --- a/extra/mariabackup/backup_mysql.cc +++ b/extra/mariabackup/backup_mysql.cc @@ -959,79 +959,93 @@ Function acquires either a backup tables lock, if supported by the server, or a global read lock (FLUSH TABLES WITH READ LOCK) otherwise. @returns true if lock acquired */ -bool -lock_tables(MYSQL *connection) +bool lock_tables(MYSQL *connection) { - if (have_lock_wait_timeout) { - /* Set the maximum supported session value for - lock_wait_timeout to prevent unnecessary timeouts when the - global value is changed from the default */ - xb_mysql_query(connection, - "SET SESSION lock_wait_timeout=31536000", false); - } + if (have_lock_wait_timeout || opt_lock_wait_timeout) + { + char buf[FN_REFLEN]; + /* Set the maximum supported session value for + lock_wait_timeout if opt_lock_wait_timeout is not set to prevent + unnecessary timeouts when the global value is changed from the default */ + snprintf(buf, sizeof(buf), "SET SESSION lock_wait_timeout=%u", + opt_lock_wait_timeout ? opt_lock_wait_timeout : 31536000); + xb_mysql_query(connection, buf, false); + } - if (have_backup_locks) { - msg("Executing LOCK TABLES FOR BACKUP..."); - xb_mysql_query(connection, "LOCK TABLES FOR BACKUP", false); - return(true); - } + if (have_backup_locks) + { + msg("Executing LOCK TABLES FOR BACKUP..."); + xb_mysql_query(connection, "LOCK TABLES FOR BACKUP", false); + return (true); + } - if (opt_lock_ddl_per_table) { - start_mdl_waiters_killer(); - } + if (opt_lock_ddl_per_table) + { + start_mdl_waiters_killer(); + } - if (!opt_lock_wait_timeout && !opt_kill_long_queries_timeout) { + if (!opt_lock_wait_timeout && !opt_kill_long_queries_timeout) + { - /* We do first a FLUSH TABLES. If a long update is running, the - FLUSH TABLES will wait but will not stall the whole mysqld, and - when the long update is done the FLUSH TABLES WITH READ LOCK - will start and succeed quickly. So, FLUSH TABLES is to lower - the probability of a stage where both mysqldump and most client - connections are stalled. Of course, if a second long update - starts between the two FLUSHes, we have that bad stall. + /* We do first a FLUSH TABLES. If a long update is running, the + FLUSH TABLES will wait but will not stall the whole mysqld, and + when the long update is done the FLUSH TABLES WITH READ LOCK + will start and succeed quickly. So, FLUSH TABLES is to lower + the probability of a stage where both mysqldump and most client + connections are stalled. Of course, if a second long update + starts between the two FLUSHes, we have that bad stall. - Option lock_wait_timeout serve the same purpose and is not - compatible with this trick. - */ + Option lock_wait_timeout serve the same purpose and is not + compatible with this trick. + */ - msg("Executing FLUSH NO_WRITE_TO_BINLOG TABLES..."); + msg("Executing FLUSH NO_WRITE_TO_BINLOG TABLES..."); - xb_mysql_query(connection, - "FLUSH NO_WRITE_TO_BINLOG TABLES", false); - } + xb_mysql_query(connection, "FLUSH NO_WRITE_TO_BINLOG TABLES", false); + } - if (opt_lock_wait_timeout) { - if (!wait_for_no_updates(connection, opt_lock_wait_timeout, - opt_lock_wait_threshold)) { - return(false); - } - } + if (opt_lock_wait_timeout) + { + if (!wait_for_no_updates(connection, opt_lock_wait_timeout, + opt_lock_wait_threshold)) + { + return (false); + } + } - msg("Executing FLUSH TABLES WITH READ LOCK..."); + msg("Executing FLUSH TABLES WITH READ LOCK..."); - if (opt_kill_long_queries_timeout) { - start_query_killer(); - } + if (opt_kill_long_queries_timeout) + { + start_query_killer(); + } - if (have_galera_enabled) { - xb_mysql_query(connection, - "SET SESSION wsrep_causal_reads=0", false); - } + if (have_galera_enabled) + { + xb_mysql_query(connection, "SET SESSION wsrep_causal_reads=0", false); + } - xb_mysql_query(connection, "FLUSH TABLES WITH READ LOCK", false); + xb_mysql_query(connection, "FLUSH TABLES WITH READ LOCK", false, true); + /* Set the maximum supported session value for + lock_wait_timeout to prevent unnecessary timeouts when the + global value is changed from the default */ + if (opt_lock_wait_timeout) + xb_mysql_query(connection, "SET SESSION lock_wait_timeout=31536000", + false); - if (opt_lock_ddl_per_table) { - stop_mdl_waiters_killer(); - } + if (opt_lock_ddl_per_table) + { + stop_mdl_waiters_killer(); + } - if (opt_kill_long_queries_timeout) { - stop_query_killer(); - } + if (opt_kill_long_queries_timeout) + { + stop_query_killer(); + } - return(true); + return (true); } - /*********************************************************************//** If backup locks are used, execute LOCK BINLOG FOR BACKUP provided that we are not in the --no-lock mode and the lock has not been acquired already. -- cgit v1.2.1