… include all queries MySQL server ran with their times and run mk-query-digest with filter to only check queries from replication thread: mk-query-digest slow-log –filter ‘($event->{user} || “”) =~ m/[SLAVE_THREAD]/’ > /tmp/report-slave.txt…
Post: Faster MySQL failover with SELECT mirroring
February 1, 2009 By 9 Comments
…. I used mk-query-digest (with some new features) to watch the traffic on the active master and replay SELECT queries against the passive… did the same on the slave. Then I used mk-query-digest to watch the traffic on the active master: mk-query-digest –processlist h=active \ –filter…
Post: Reasons for MySQL Replication Lag
July 29, 2011 By 6 Comments
… to analyze your replication traffic regularly with mk-query-digest (Percona Server marks Slave Thread in slow query log so it is easy to filter… to concurrent traffic on the slave can affect replication capacity a lot. Checking traffic for changes with mk-query-digest is a great way…
Post: The story of one MySQL Upgrade
October 8, 2010 By 8 Comments
… both slaves at the same position again and used tcpdump and mk-query-digest to get sample read traffic from both master and slave. –sample=50 (or similar) option is important to check only limited number of samples for each query type – otherwise it can take a lot of time. Running mk-upgrade with these queries showed some results…
Post: Upgrading MySQL
January 5, 2010 By 23 Comments
… backup of the database and get query log (you can use mk-query-digest with tcpdump to sniff out queries if you can’t enable… 2 same boxes and use mk-upgrade tool to run comparison. The tool will run SELECT queries on both new and old… is not possible as MySQL only fully support slaves newer than the master. Older slaves may have issues unable to interpret new…
