[ 
https://issues.apache.org/jira/browse/HDFS-7964?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15145511#comment-15145511
 ] 

Hadoop QA commented on HDFS-7964:
---------------------------------

| (x) *{color:red}-1 overall{color}* |
\\
\\
|| Vote || Subsystem || Runtime || Comment ||
| {color:blue}0{color} | {color:blue} reexec {color} | {color:blue} 0m 0s 
{color} | {color:blue} Docker mode activated. {color} |
| {color:red}-1{color} | {color:red} patch {color} | {color:red} 0m 4s {color} 
| {color:red} HDFS-7964 does not apply to trunk. Rebase required? Wrong Branch? 
See https://wiki.apache.org/hadoop/HowToContribute for help. {color} |
\\
\\
|| Subsystem || Report/Notes ||
| JIRA Patch URL | 
https://issues.apache.org/jira/secure/attachment/12767604/HDFS-7964.patch |
| JIRA Issue | HDFS-7964 |
| Console output | 
https://builds.apache.org/job/PreCommit-HDFS-Build/14486/console |
| Powered by | Apache Yetus 0.2.0-SNAPSHOT   http://yetus.apache.org |


This message was automatically generated.



> Add support for async edit logging
> ----------------------------------
>
>                 Key: HDFS-7964
>                 URL: https://issues.apache.org/jira/browse/HDFS-7964
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>          Components: namenode
>    Affects Versions: 2.0.2-alpha
>            Reporter: Daryn Sharp
>            Assignee: Daryn Sharp
>         Attachments: HDFS-7964.patch, HDFS-7964.patch, HDFS-7964.patch
>
>
> Edit logging is a major source of contention within the NN.  LogEdit is 
> called within the namespace write log, while logSync is called outside of the 
> lock to allow greater concurrency.  The handler thread remains busy until 
> logSync returns to provide the client with a durability guarantee for the 
> response.
> Write heavy RPC load and/or slow IO causes handlers to stall in logSync.  
> Although the write lock is not held, readers are limited/starved and the call 
> queue fills.  Combining an edit log thread with postponed RPC responses from 
> HADOOP-10300 will provide the same durability guarantee but immediately free 
> up the handlers.



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

Reply via email to