Looking for anything such as known bugs in Sql Server 2016 SP1, CU4 and CU5 (both have same issue) on windows 2012 R2 on vmware. Esp. if where parallel threads wait on each other.
Issue: After going production we have one specific query in an SSIS dataflow that was very poorly performing in 2016 (was fine in 2012). So I found some indexes needed to be added so added them which cut down on runtime by about 80%. Then it started randomly freezing (say once or twice a day) never returning any rows. Doesn't seem to correlate to how busy the server is, locks, or data volume. We have very high cxpacket waits but who doesn't? I'm running maxdop 8 with 12 virtual cores.
Activity monitor very often shows session id is blocked by same session id on 2016. I never looked on 2012 to see if this happens. It also shows this when a query hangs. No deadlocks. I'm running with option recompile and default server maxdop 8 (database is maxdop 0).
Any ideas greatly appreciated.