[jira] [Commented] (HIVE-16854) SparkClientFactory is locked too aggressively

["Xuefu Zhang (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HIVE-16854?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16042139#comment-16042139 ] 

Xuefu Zhang commented on HIVE-16854:
------------------------------------

cc: [~lirui]

> SparkClientFactory is locked too aggressively
> ---------------------------------------------
>
>                 Key: HIVE-16854
>                 URL: https://issues.apache.org/jira/browse/HIVE-16854
>             Project: Hive
>          Issue Type: Bug
>          Components: Spark
>    Affects Versions: 1.1.0
>            Reporter: Xuefu Zhang
>
> Most methods in SparkClientFactory are synchronized on the SparkClientFactory singleton. However, some methods are very expensive, such as createClient(), which returns a SparkClientImpl instance. However, creating a SparkClientImpl instance requires starting a remote driver to connect back to RPCServer. This process can take a long time such as in case of a busy yarn queue. When this happens, all pending  calls on SparkClientFactory will have to wait for a long time.
> In our case, hive.spark.client.server.connect.timeout is set to 1hr. This makes some queries waiting for hours before starting.
> The current implementation seems pretty much making all remote driver launches serialized. If one of them takes time, the following ones will have to wait.
> HS2 stacktrace is attached for reference. It's based on earlier version of Hive, so the line numbers might be slightly off.



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