[jira] [Commented] (HIVE-15796) HoS: poor reducer parallelism when operator stats are not accurate

["Hive QA (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HIVE-15796?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15851034#comment-15851034 ] 

Hive QA commented on HIVE-15796:
--------------------------------



Here are the results of testing the latest attachment:
https://issues.apache.org/jira/secure/attachment/12850735/HIVE-15796.wip.patch

{color:red}ERROR:{color} -1 due to no test(s) being added or modified.

{color:red}ERROR:{color} -1 due to 13 failed/errored test(s), 11027 tests executed
*Failed tests:*
{noformat}
TestDerbyConnector - did not produce a TEST-*.xml file (likely timed out) (batchId=235)
org.apache.hadoop.hive.cli.TestCliDriver.testCliDriver[index_auto_mult_tables] (batchId=78)
org.apache.hadoop.hive.cli.TestEncryptedHDFSCliDriver.testCliDriver[encryption_join_with_different_encryption_keys] (batchId=159)
org.apache.hadoop.hive.cli.TestPerfCliDriver.testCliDriver[query14] (batchId=223)
org.apache.hadoop.hive.cli.TestPerfCliDriver.testCliDriver[query23] (batchId=223)
org.apache.hadoop.hive.cli.TestSparkCliDriver.testCliDriver[auto_sortmerge_join_12] (batchId=109)
org.apache.hadoop.hive.cli.TestSparkCliDriver.testCliDriver[bucket_map_join_tez1] (batchId=131)
org.apache.hadoop.hive.cli.TestSparkCliDriver.testCliDriver[bucket_map_join_tez2] (batchId=100)
org.apache.hadoop.hive.cli.TestSparkCliDriver.testCliDriver[cross_product_check_2] (batchId=133)
org.apache.hadoop.hive.cli.TestSparkCliDriver.testCliDriver[mapjoin_mapjoin] (batchId=116)
org.apache.hadoop.hive.cli.TestSparkCliDriver.testCliDriver[smb_mapjoin_25] (batchId=99)
org.apache.hadoop.hive.cli.TestSparkCliDriver.testCliDriver[subquery_multiinsert] (batchId=131)
org.apache.hadoop.hive.llap.daemon.impl.TestTaskExecutorService.testWaitQueuePreemption (batchId=282)
{noformat}

Test results: https://builds.apache.org/job/PreCommit-HIVE-Build/3342/testReport
Console output: https://builds.apache.org/job/PreCommit-HIVE-Build/3342/console
Test logs: http://104.198.109.242/logs/PreCommit-HIVE-Build-3342/

Messages:
{noformat}
Executing org.apache.hive.ptest.execution.TestCheckPhase
Executing org.apache.hive.ptest.execution.PrepPhase
Executing org.apache.hive.ptest.execution.ExecutionPhase
Executing org.apache.hive.ptest.execution.ReportingPhase
Tests exited with: TestsFailedException: 13 tests failed
{noformat}

This message is automatically generated.

ATTACHMENT ID: 12850735 - PreCommit-HIVE-Build

> HoS: poor reducer parallelism when operator stats are not accurate
> ------------------------------------------------------------------
>
>                 Key: HIVE-15796
>                 URL: https://issues.apache.org/jira/browse/HIVE-15796
>             Project: Hive
>          Issue Type: Improvement
>          Components: Statistics
>    Affects Versions: 2.2.0
>            Reporter: Chao Sun
>            Assignee: Chao Sun
>         Attachments: HIVE-15796.wip.patch
>
>
> In HoS we use currently use operator stats to determine reducer parallelism. However, it is often the case that operator stats are not accurate, especially if column stats are not available. This sometimes will generate extremely poor reducer parallelism, and cause HoS query to run forever. 
> This JIRA tries to offer an alternative way to compute reducer parallelism, similar to how MR does. Here's the approach we are suggesting:
> 1. when computing the parallelism for a MapWork, use stats associated with the TableScan operator;
> 2. when computing the parallelism for a ReduceWork, use the *maximum* parallelism from all its parents.



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