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https://issues.apache.org/jira/browse/HDFS-5241?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13777728#comment-13777728
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Suresh Srinivas commented on HDFS-5241:
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@Daryn, quick question. Current semantics at Namenode is, when operation is
received:
# Takes the FSNamesystem lock
#* Operation updates the inmemory state
#* Adds an editlog entry
#* Gives up FSNamesystem lock
# Logs an audit event
# Returns response to the client
That is, by the time response is returned, auditlog is updated.
With this change, it is possible to return a response to the client and
auditlog may not have been updated. Is that not a concern?
> Provide alternate queuing audit logger to reduce logging contention
> -------------------------------------------------------------------
>
> Key: HDFS-5241
> URL: https://issues.apache.org/jira/browse/HDFS-5241
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: namenode
> Affects Versions: 2.0.0-alpha, 3.0.0
> Reporter: Daryn Sharp
> Assignee: Daryn Sharp
> Attachments: HDFS-5241.patch
>
>
> The default audit logger has extremely poor performance. The internal
> synchronization of log4j causes massive contention between the call handlers
> (100 by default) which drastically limits the throughput of the NN.
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