You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@spark.apache.org by "Zhenhua Wang (JIRA)" <ji...@apache.org> on 2017/10/29 15:01:06 UTC
[jira] [Commented] (SPARK-22394) Redundant synchronization for
metastore access
[ https://issues.apache.org/jira/browse/SPARK-22394?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16224028#comment-16224028 ]
Zhenhua Wang commented on SPARK-22394:
--------------------------------------
[~cloud_fan] [~smilegator] [~rxin] Do I understand it correctly, or do I miss something?
> Redundant synchronization for metastore access
> ----------------------------------------------
>
> Key: SPARK-22394
> URL: https://issues.apache.org/jira/browse/SPARK-22394
> Project: Spark
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 2.3.0
> Reporter: Zhenhua Wang
>
> Before Spark 2.x, synchronization for metastore access was protected at [line229 in ClientWrapper |https://github.com/apache/spark/blob/branch-1.6/sql/hive/src/main/scala/org/apache/spark/sql/hive/client/ClientWrapper.scala#L229] (now it's at [line203 in HiveClientWrapper |https://github.com/apache/spark/blob/master/sql/hive/src/main/scala/org/apache/spark/sql/hive/client/HiveClientImpl.scala#L203]). After Spark 2.x, HiveExternalCatalog was introduced by [SPARK-13080|https://github.com/apache/spark/pull/11293], where an extra level of synchronization was added at [line95|https://github.com/apache/spark/blob/master/sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveExternalCatalog.scala#L95]. That is, now we have two levels of synchronization: one is HiveExternalCatalog and the other is IsolatedClientLoader in HiveClientImpl. But since both HiveExternalCatalog and IsolatedClientLoader are shared among all spark sessions, I think the extra level of synchronization in HiveExternalCatalog is redundant, thus can be removed.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org