Gopal V created HIVE-16282:
------------------------------

             Summary: Semijoin: Disable slow-start for the bloom filter 
aggregate task
                 Key: HIVE-16282
                 URL: https://issues.apache.org/jira/browse/HIVE-16282
             Project: Hive
          Issue Type: Bug
    Affects Versions: 2.2.0
            Reporter: Gopal V


The slow-start of the bloom filter vertex is a scheduling problem which causes 
more pre-emption than is useful.

When the bloom filters are arranged as follows

Map 1(10 tasks)->Reducer 2(1 task)->Map 3(100 tasks)

Map 3 and Map 1 are immediately active since Reducer 2 -> Map 3 is a broadcast 
edge.

Once 3 tasks in Map 1 finish, the engine kills one active task from Map 3 to 
make room for Reducer 2.




--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Reply via email to