GilaMonster (9/1/2015)
It's normal for sessions in parallel to 'block' each other.
Now, maybe they shouldn't be running in parallel, maybe there are missing indexes, maybe there's badly written code. Either could cause queries to run in parallel and less efficiently than they should.
Stop looking at individual symptoms. Investigate, analyse and identify the causes of whatever problem you have, then you'll be in a good position to suggest and implement a fix for whatever problems you're having.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability