[
https://issues.apache.org/jira/browse/YARN-202?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Vinod Kumar Vavilapalli updated YARN-202:
-----------------------------------------
Issue Type: Sub-task (was: Bug)
Parent: YARN-431
> Log Aggregation generates a storm of fsync() for namenode
> ---------------------------------------------------------
>
> Key: YARN-202
> URL: https://issues.apache.org/jira/browse/YARN-202
> Project: Hadoop YARN
> Issue Type: Sub-task
> Affects Versions: 2.0.2-alpha, 0.23.4
> Reporter: Kihwal Lee
> Assignee: Kihwal Lee
> Priority: Critical
> Fix For: 3.0.0, 2.0.3-alpha, 0.23.5
>
> Attachments: yarn-202.patch
>
>
> When the log aggregation is on, write to each aggregated container log causes
> hflush() to be called. For large clusters, this can creates a lot of fsync()
> calls for namenode.
> We have seen 6-7x increase in the average number of fsync operations compared
> to 1.0.x on a large busy cluster. Over 99% of fsync ops were for log
> aggregation writing to tmp files.
--
This message was sent by Atlassian JIRA
(v6.1#6144)
