Recently I was working with a customer where we noticed that Seconds_Behind_Master fluctuating from an expected value of 0 seconds behind to a fairly high six figure value.  The servers were configured in a master-master relationship and used 5 figure server_id values, and we had just migrated this cluster from one data centre to another by re-pointing masters.  Seeing large fluctuations in Seconds_Behind_Master can often be explained by long running queries being processed by the SQL_THREAD, however SHOW PROCESSLIST indicated that there were no long running replication events, and we had no other indication that the server was lagging  due to resource constraints — CPU, disk, and memory were under-utilized.

We then moved our investigation to manual review of the binary log where events appeared normal (5 digit server_id values) until every once in a while we would see a rash of server_id 21 events.. Wait, what?  I …

Today we’re celebrating Percona’s 7th anniversary.  A lot has changed in these past 7 years – we have grown from a two-person outfit focused exclusively on consulting to a 100-person company with teammates in 22 different countries and 18 different states, now providing Support, Consulting, RemoteDBA, Server Development and Training services.

We also made our mark in open source software development, creating some of the most popular …

We’re less than a week away from Percona MySQL University at Portland, Oregon next Monday, June 17. The latest in a series of FREE one-day educational events, we are pleased to feature 10 technical talks by members of Team Percona as well as local members of the MySQL Community:

• Vadim Tkachenko, Percona co-Founder and CTO, will talk about Percona XtraDB Cluster, …