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https://issues.apache.org/jira/browse/HIVE-15565?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15824655#comment-15824655
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Sergey Shelukhin commented on HIVE-15565:
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Looking at it again (and at [~prasanth_j] 's comment that I cannot quite
understand)... what is the task configured memory that we are no longer using?
Is it set based on Tez executor size (or equivalent) in MapRecordProcessor?
It's set from Tez context.
Also, why is this causing single-record flushes if we base on task memory?
> LLAP: GroupByOperator flushes hash table too frequently
> -------------------------------------------------------
>
> Key: HIVE-15565
> URL: https://issues.apache.org/jira/browse/HIVE-15565
> Project: Hive
> Issue Type: Bug
> Components: llap
> Reporter: Rajesh Balamohan
> Assignee: Rajesh Balamohan
> Priority: Minor
> Fix For: 2.2.0
>
> Attachments: HIVE-15565.1.patch
>
>
> {{GroupByOperator::isTez}} would be true in LLAP mode. Current memory
> computations can go wrong with {{isTez}} checks in {{GroupByOperator}}. For
> e.g, in a LLAP instance with Xmx128G and 12 executors, it would start
> flushing hash table for every record once it reaches around 42GB
> (hive.tez.container.size=7100, hive.map.aggr.hash.percentmemory=0.5).
> {noformat}
> 2017-01-08T23:40:21,339 INFO [TezTaskRunner
> (1480722417364_1922_7_03_000004_1)]
> org.apache.hadoop.hive.ql.exec.GroupByOperator: Hash Table flushed: new size
> = 0
> 2017-01-08T23:40:21,339 INFO [TezTaskRunner
> (1480722417364_1922_7_03_000012_1)]
> org.apache.hadoop.hive.ql.exec.GroupByOperator: Hash Table flushed: new size
> = 0
> 2017-01-08T23:40:21,339 INFO [TezTaskRunner
> (1480722417364_1922_7_03_000004_1)]
> org.apache.hadoop.hive.ql.exec.GroupByOperator: Hash Tbl flush: #hash table =
> 1
> 2017-01-08T23:40:21,339 INFO [TezTaskRunner
> (1480722417364_1922_7_03_000012_1)]
> org.apache.hadoop.hive.ql.exec.GroupByOperator: Hash Tbl flush: #hash table =
> 1
> {noformat}
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