tez-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Siddharth Seth (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (TEZ-1911) MergeManager's unconditionalReserve() should check for memory limits before allocating memory to IntermediateMemoryToMemoryMerger
Date Fri, 26 Feb 2016 18:05:18 GMT

    [ https://issues.apache.org/jira/browse/TEZ-1911?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15169442#comment-15169442
] 

Siddharth Seth commented on TEZ-1911:
-------------------------------------

Please go ahead.

> MergeManager's unconditionalReserve() should check for memory limits before allocating
memory to IntermediateMemoryToMemoryMerger
> ---------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: TEZ-1911
>                 URL: https://issues.apache.org/jira/browse/TEZ-1911
>             Project: Apache Tez
>          Issue Type: Bug
>            Reporter: Rajesh Balamohan
>            Assignee: Rajesh Balamohan
>             Fix For: 0.8.3
>
>         Attachments: TEZ-1911.1.patch, TEZ-1911.2.patch, TEZ-1911.3.patch
>
>
> Currently, IntermediateMemoryToMemoryMerger invokes unconditionalReserve() to get the
memory needed for intermediate mem-to-mem merging.  It could potentially cause issue in the
following scenario
> 1. tez.runtime.io.sort.factor set to 100 and assume shuffled data (e.g 60% memory occupied)
haven't reached TEZ_RUNTIME_SHUFFLE_MERGE_PERCENT_DEFAULT
> 2. Assume that it reaches the sort.factor threshold before reaching merge threshold.
 This would kick in IntermediateMemoryToMemoryMerger.
> In IntermediateMemoryToMemoryMerger, it would try to allocate additional 60% without
any boundary checks.  This could lead to OOM depending on the tez.runtime.io.sort.mb setting.



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

Mime
View raw message