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Showing posts from July, 2015

Enhancing MySQL Query Performance - July 2015

Background This post is meant to document steps that I took in July 2015 to fix a MySQL-related performance problem.  Problem Identification The symptoms is that pages of one application have very large response time. First thing we check is the CPU usage of the application server, which is < 25%, meaning that there are no issue in the application servers' CPU usage. And need to check logical limits also, in this case, Apache's MaxClients.. and compare it with the concurrent HTTP connections to the server. This is also < 25%. The second part we check is the database server. Check the CPU usage.. and gotcha, it was > 70%. With application server have almost no load,  this means query executions in the database server were not optimal. Next we check the queries. MySQL Processlist To examine queries running in a MySQL database server, open mysql command line client, and we could check the processlist using : SHOW FULL PROCESSLIST \G This should be ru