You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@spark.apache.org by "Apache Spark (JIRA)" <ji...@apache.org> on 2018/02/03 02:45:00 UTC
[jira] [Assigned] (SPARK-23310) Perf regression introduced by
SPARK-21113
[ https://issues.apache.org/jira/browse/SPARK-23310?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Apache Spark reassigned SPARK-23310:
------------------------------------
Assignee: (was: Apache Spark)
> Perf regression introduced by SPARK-21113
> -----------------------------------------
>
> Key: SPARK-23310
> URL: https://issues.apache.org/jira/browse/SPARK-23310
> Project: Spark
> Issue Type: Bug
> Components: Spark Core
> Affects Versions: 2.3.0
> Reporter: Yin Huai
> Priority: Blocker
>
> While running all TPC-DS queries with SF set to 1000, we noticed that Q95 (https://github.com/databricks/spark-sql-perf/blob/master/src/main/resources/tpcds_2_4/q95.sql) has noticeable regression (11%). After looking into it, we found that the regression was introduced by SPARK-21113. Specially, ReadAheadInputStream gets lock congestion. After setting spark.unsafe.sorter.spill.read.ahead.enabled set to false, the regression disappear and the overall performance of all TPC-DS queries has improved.
>
> I am proposing that we set spark.unsafe.sorter.spill.read.ahead.enabled to false by default for Spark 2.3 and re-enable it after addressing the lock congestion issue.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org