From b5f8ee61a7f7e9bd291dd26b0585d03eb686c941 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 5 May 2024 13:19:16 +0200 Subject: Adding upstream version 1.46.3. Signed-off-by: Daniel Baumann --- health/guides/mysql/mysql_replication_lag.md | 30 ---------------------------- 1 file changed, 30 deletions(-) delete mode 100644 health/guides/mysql/mysql_replication_lag.md (limited to 'health/guides/mysql/mysql_replication_lag.md') diff --git a/health/guides/mysql/mysql_replication_lag.md b/health/guides/mysql/mysql_replication_lag.md deleted file mode 100644 index 9c57f8108..000000000 --- a/health/guides/mysql/mysql_replication_lag.md +++ /dev/null @@ -1,30 +0,0 @@ -### Understand the alert - -This alert presents the number of seconds that the replica is behind the master. Receiving this means that the replication SQL thread is far behind processing the source binary log. A constantly high value (or an increasing one) indicates that the replica is unable to handle events from the source in a timely fashion. - -This alert is raised into warning when the metric exceeds 10 seconds. If the number of seconds that the replica is behind the master exceeds 30 seconds then the alert is raised into critical. - - -### Troubleshoot the alert - -- Query optimization and "log_slow_slave_statements" - -To minimize slave `SQL_THREAD` lag, focus on query optimization. The following logs will help you identify the problem: -1. Enable [log_slow_slave_statements](https://dev.mysql.com/doc/refman/8.0/en/replication-options-replica.html#sysvar_log_slow_slave_statements) to see queries executed by slave that take more than [long_query_time](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_long_query_time). -2. To get more information about query performance, set the configuration option [log_slow_verbosity](https://www.percona.com/doc/percona-server/5.1/diagnostics/slow_extended.html?id=percona-server:features:slow_extended_51&redirect=2#log_slow_verbosity) to `full`. - -You can also read the Percona blog for a nice write-up about[MySQL replication slave lag](https://www.percona.com/blog/2014/05/02/how-to-identify-and-cure-mysql-replication-slave-lag/). - -### Useful resources - -1. [Replication in MySQL]( - https://www.digitalocean.com/community/tutorials/how-to-set-up-replication-in-mysql) -2. [MySQL Replication Slave Lag]( - https://www.percona.com/blog/2014/05/02/how-to-identify-and-cure-mysql-replication-slave-lag/) -3. [log_slow_slave_statements]( - https://dev.mysql.com/doc/refman/8.0/en/replication-options-replica.html#sysvar_log_slow_slave_statements) -4. [long_query_time]( - https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_long_query_time) -5. [log_slow_verbosity]( - https://www.percona.com/doc/percona-server/5.1/diagnostics/slow_extended.html?id=percona-server:features:slow_extended_51&redirect=2#log_slow_verbosity) - -- cgit v1.2.3