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https://issues.apache.org/jira/browse/HIVE-17573?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16312596#comment-16312596
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liyunzhang commented on HIVE-17573:
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[~gopalv]: thanks for your reply and tool.
bq.JDK9 seems to wake up the producer-consumer pair on the same NUMA zone (the
IO elevator allocates, passes the array to the executor thread and executor
passes it back instead of throwing it to GC deref).
If I don't add {{-XX:+UseNUMA}}, I guess the optimization about NUMA handling
will not benefit the query, is it right? UseNUMA is disabled by default.
bq.the IO elevator allocates, passes the array to the executor thread and
executor passes it back instead of throwing it to GC deref
I guess this will reduce less GC.
>From my test result, what i found is GC is less in JDK9 comparing JDK8 on Hive
>on Spark in long
>queries([link|https://docs.google.com/presentation/d/1cK9ZfUliAggH3NJzSvexTPwkXpbsM7Dm0o0kdmuFQUU/edit#slide=id.p]).
> Maybe this is because G1GC is the default garbage collector and the purpose
>of
>[G1GC|https://docs.oracle.com/javase/9/gctuning/garbage-first-garbage-collector.htm#JSGCT-GUID-0394E76A-1A8F-425E-A0D0-B48A3DC82B42]
> is less GC time.
> LLAP: JDK9 support fixes
> ------------------------
>
> Key: HIVE-17573
> URL: https://issues.apache.org/jira/browse/HIVE-17573
> Project: Hive
> Issue Type: Bug
> Components: llap
> Affects Versions: 3.0.0
> Reporter: Gopal V
> Assignee: Gopal V
>
> The perf diff between JDK8 -> JDK9 seems to be significant.
> TPC-H Q6 on JDK8 takes 32s on a single node + 1 Tb scale warehouse.
> TPC-H Q6 on JDK9 takes 19s on the same host + same data.
> The performance difference seems to come from better JIT and better NUMA
> handling.
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