Github user kkhatua commented on the issue:
https://github.com/apache/drill/pull/1200
@paul-rogers very good point about the issue of the heartbeat thread
competing with other Drillbit process threads for CPU. When writing up the
documentation for this, we'll have to ensure that users also configure the
parallelization to a reasonable level to ensure that CPU thrashing is minimized
with CGroups enforced. ---
