Mysql replication invalidating query cache entries table updating blackberry storm to version 5
First because i dont't see the servers processing anything, and second, because as i mentiomed in update4, the server stops processing and gets stuck on invalidating cache on the old non-Percona servers which caused the replication to halt until the cache was invalidated (Which took a lot of time). id=60696 We solved the issue by moving entirely to Percona My SQL server v5.5 which has the ability to disable Query Cache completely.We lately mved to My SQL V5.5 on Cent OS release 6.7 with master and 2 slaves.That is related to a known bug, fixed in My SQL 5.5 :
The query mutex becomes a very hot spot especially if you are using RBR. It often happens to see and hear of replication SQL thread almost always in state “invalidating query cache entries (table)” .While sometime this works, others don’t; the query cache is “disabled” and you still see the SQL thread in state “invalidating query cache entries (table)”.In a situation like this, the query cache can mask performance problems caused by missing indexes, which makes it helpful for novice users.with "mytop" being an own Debian package, while "innotop" is included in the "mysql-client" package.