[
https://issues.apache.org/jira/browse/HDFS-6871?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14110068#comment-14110068
]
Yi Liu commented on HDFS-6871:
------------------------------
[~daryn], about removing blocks after the lock is released and logSync, we get
more discussion and reason from HDFS-2938, HDFS-2815.
{quote}but recent 2.x edit log corruption bugs have installed a healthy fear in
me.{quote}
Which JIRA are you referring to? We can look into the detail.
> Improve NameNode performance when creating file
> -------------------------------------------------
>
> Key: HDFS-6871
> URL: https://issues.apache.org/jira/browse/HDFS-6871
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: namenode, performance
> Reporter: Yi Liu
> Assignee: Yi Liu
> Priority: Critical
> Fix For: 2.6.0
>
> Attachments: HDFS-6871.001.patch, HDFS-6871.002.patch,
> HDFS-6871.003.patch
>
>
> Creating file with overwrite flag will cause NN fall into flush edit logs and
> block other requests if the file exists.
> When we create a file with overwrite flag (default is true) in HDFS, NN will
> remove original file if it exists. In FSNamesystem#startFileInternal, NN
> already holds the write lock, it calls {{deleteInt}} if the file exists,
> there is logSync in {{deleteInt}}. So in this case, logSync is under write
> lock, it will heavily affect the NN performance.
> We should ignore the force logSync in {{deleteInt}} in this case.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
