Prasanth Jayachandran created HIVE-23443:
--------------------------------------------
Summary: LLAP speculative task pre-emption seems to be not working
Key: HIVE-23443
URL: https://issues.apache.org/jira/browse/HIVE-23443
Project: Hive
Issue Type: Bug
Reporter: Prasanth Jayachandran
I think after HIVE-23210 we are getting a stable sort order in pre-emption
queue and it is causing pre-emption to not work in certain cases.
{code:java}
"attempt_1589167813851_0000_119_01_000008_0
(hive_20200511055921_89598f09-19f1-4969-ab7a-82e2dd796273-119/Map 1, started at
2020-05-11 05:59:22, in preemption queue, can finish)",
"attempt_1589167813851_0008_84_01_000008_1
(hive_20200511055928_7ae29ca3-e67d-4d1f-b193-05651023b503-84/Map 1, started at
2020-05-11 06:00:23, in preemption queue, can finish)" {code}
Scheduler only peek's at the pre-emption queue and looks at whether it is
non-finishable.
[https://github.com/apache/hive/blob/master/llap-server/src/java/org/apache/hadoop/hive/llap/daemon/impl/TaskExecutorService.java#L420]
In the above case, all tasks are speculative but state change is not triggering
pre-emption queue re-ordering so peek() always returns canFinish task even
though non-finishable tasks are in the queue.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
