Running Percona Server 5.5.38-35.2-log, and looking at the pt-query-digest report from our slow log (set to 2 seconds). Many of the queries reported are simple index-supported SELECTS, but they are showing the majority of the time as “queue wait”. I’ve been researching, but it is not clear to me what that is counting. Can someone shed some light on what that means? Here is an example
As stated in http://www.percona.com/doc/percona-server/5.1/diagnostics/slow_extended.html?id=percona-server:features:slow_extended_51&redirect=2 , this is an additional statistics added in the slow log entry. As stated in that link:
innodb_queue_wait: Shows how long (in seconds) the query spent either waiting to enter the InnoDB queue or inside that queue waiting for execution.