[jira] [Reopened] (HIVE-13149) Remove some unnecessary HMS connections from HS2

["Aihua Xu (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-13149?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Aihua Xu reopened HIVE-13149:
-----------------------------

Seems it caused TestJdbcWithMiniHS2 to fail. Reverted the patch and will look into that.

> Remove some unnecessary HMS connections from HS2 
> -------------------------------------------------
>
>                 Key: HIVE-13149
>                 URL: https://issues.apache.org/jira/browse/HIVE-13149
>             Project: Hive
>          Issue Type: Sub-task
>          Components: HiveServer2
>    Affects Versions: 2.0.0
>            Reporter: Aihua Xu
>            Assignee: Aihua Xu
>             Fix For: 2.1.0
>
>         Attachments: HIVE-13149.1.patch, HIVE-13149.2.patch, HIVE-13149.3.patch, HIVE-13149.4.patch, HIVE-13149.5.patch, HIVE-13149.6.patch, HIVE-13149.7.patch
>
>
> In SessionState class, currently we will always try to get a HMS connection in {{start(SessionState startSs, boolean isAsync, LogHelper console)}} regardless of if the connection will be used later or not. 
> When SessionState is accessed by the tasks in TaskRunner.java, although most of the tasks other than some like StatsTask, don't need to access HMS. Currently a new HMS connection will be established for each Task thread. If HiveServer2 is configured to run in parallel and the query involves many tasks, then the connections are created but unused.
> {noformat}
>   @Override
>   public void run() {
>     runner = Thread.currentThread();
>     try {
>       OperationLog.setCurrentOperationLog(operationLog);
>       SessionState.start(ss);
>       runSequential();
> {noformat}



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)