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https://issues.apache.org/jira/browse/FLINK-14952?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16989448#comment-16989448
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Yingjie Cao commented on FLINK-14952:
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[~gjy] By "FILE-FILE" mode, I mean using BoundedBlockingSubpartitionType.FILE.
As explained by [~pnowojski], results are written to a file and read from a
file using read/write API of FileChannel. When reading from files, two buffers
are needed by each subpartition to store the read data. For MMAP read mode, the
extra read buffers are not needed.
> Yarn containers can exceed physical memory limits when using
> BoundedBlockingSubpartition.
> -----------------------------------------------------------------------------------------
>
> Key: FLINK-14952
> URL: https://issues.apache.org/jira/browse/FLINK-14952
> Project: Flink
> Issue Type: Bug
> Components: Deployment / YARN, Runtime / Network
> Affects Versions: 1.9.1
> Reporter: Piotr Nowojski
> Priority: Blocker
> Fix For: 1.10.0
>
>
> As [reported by a user on the user mailing
> list|http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/CoGroup-SortMerger-performance-degradation-from-1-6-4-1-9-1-td31082.html],
> combination of using {{BoundedBlockingSubpartition}} with yarn containers
> can cause yarn container to exceed memory limits.
> {quote}2019-11-19 12:49:23,068 INFO org.apache.flink.yarn.YarnResourceManager
> - Closing TaskExecutor connection container_e42_1574076744505_9444_01_000004
> because: Container
> [pid=42774,containerID=container_e42_1574076744505_9444_01_000004] is running
> beyond physical memory limits. Current usage: 12.0 GB of 12 GB physical
> memory used; 13.9 GB of 25.2 GB virtual memory used. Killing container.
> {quote}
> This is probably happening because memory usage of mmap is not capped and not
> accounted by configured memory limits, however yarn is tracking this memory
> usage and once Flink exceeds some threshold, container is being killed.
> Workaround is to overrule default value and force Flink to not user mmap, by
> setting a secret (🤫) config option:
> {noformat}
> taskmanager.network.bounded-blocking-subpartition-type: file
> {noformat}
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