We lately moved to MySQL V5.5 on CentOS release 6.7 with master and 2 slaves. Since then the replication process lags a lot behind the master with the line in the process list of:
invalidating query cache entries (table).
The global query_cache_type & size were set to 0.
I have checked around and I can see it's a known old bug in MySQL but could not find a workaround for this issue.
Any advice?