We've only just upgraded t 1.2 in the last week, and since we have we seem to be gettting a spike everyday sometime in our afternoons which causes major problems. We run a pretty big forum, that is configured to run off multiple scaling web servers accessing an independent database, memcached and elastisearch servers. Up until the upgrade the servers were running anywhere between 30% & 90% without issue. Since the upgrade, we have daily issues where there is a sudden spike and our cpu will jump from 60% to 100% in a minute or two,this causes our servers to suddenly start throwing back 500's before the load balancer kicks them off. I've checkd for DDOS or other traffic spikes, also the database server is happy and no sign of issues with memcached, and anyway they were not causing any issue prior to 1.2 so I am guess that it might some daily job. RAM is not an issue and I/O appears to b insignificant as well. Anyone know of any likely culprits?