Query cache should be invalidated in non-PRIMARY

[Raghavendra D Prabhu]

When query cache is used and a node goes into non-PRIM state, queries which returned results earlier (and cached into query cache) still return results whereas newer queries (or the ones not cached) return 'unknown command'. This inconsistent return of results should be prevented by invalidating query cache when a node becomes non-PRIM (or when wsrep_ready is OFF).

[Raghavendra D Prabhu (raghavendra-prabhu)]

=== modified file 'sql/wsrep_mysqld.cc'
--- sql/wsrep_mysqld.cc 2014-04-20 17:19:52 +0000
+++ sql/wsrep_mysqld.cc 2014-04-20 18:36:58 +0000
@@ -230,6 +230,10 @@

   /* Proceed further only if view is PRIMARY */
   if (WSREP_VIEW_PRIMARY != view->status) {
+#ifdef HAVE_QUERY_CACHE
+ // query cache must be initialised by now
+ query_cache.flush();
+#endif /*HAVE_QUERY_CACHE*/
     wsrep_ready_set(FALSE);
     new_status= WSREP_MEMBER_UNDEFINED;
     /* Always record local_uuid and local_seqno in non-prim since this

in wsrep_view_handler_cb should do.

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PXC-1655