Hi Brain, I think Gabriel talked about memory leak in query cache + xtradb (or innodb) Elena put this comment in JIRA: The fix should be in 5.5.32 release. The bug was fixed in XtraDB 5.5.32 (at least it is marked as such in https://bugs.launchpad.net/percona-server/+bug/1170103), and MariaDB 5.5.32 includes XtraDB 5.5.32. We didn't have a reproducible test case to verify it, so please re-open the issue (or comment on it to get it re-opened) if you still have the problem with MariaDB 5.5.32, and reporter (Gabriel), send this comment: Gabriel Sosa<https://mariadb.atlassian.net/secure/ViewProfile.jspa?name=pendexgabo> added a comment - Today 14:01 excellent! perfect. Thanks for your time Gabriel, i made this: try a small database with 5.5.32 and check if bug persist, if not, upgrade production servers without problems i updated 3 production servers and they are working normally without the bug and query cache enabled, i'm using xtradb (not innodb plugin)