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https://issues.apache.org/jira/browse/HDFS-3077?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13473397#comment-13473397
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Aaron T. Myers commented on HDFS-3077:
--------------------------------------

bq. I still don't understand why this is _better_ and not just _different_.

+1. I personally find the protocol as it exists now easier to understand than 
this proposed change would be. It makes more sense to me to separate these two 
operations, which are in fact different semantic operations with different 
purposes.
                
> Quorum-based protocol for reading and writing edit logs
> -------------------------------------------------------
>
>                 Key: HDFS-3077
>                 URL: https://issues.apache.org/jira/browse/HDFS-3077
>             Project: Hadoop HDFS
>          Issue Type: New Feature
>          Components: ha, name-node
>            Reporter: Todd Lipcon
>            Assignee: Todd Lipcon
>             Fix For: QuorumJournalManager (HDFS-3077)
>
>         Attachments: hdfs-3077-partial.txt, hdfs-3077-test-merge.txt, 
> hdfs-3077.txt, hdfs-3077.txt, hdfs-3077.txt, hdfs-3077.txt, hdfs-3077.txt, 
> hdfs-3077.txt, hdfs-3077.txt, qjournal-design.pdf, qjournal-design.pdf, 
> qjournal-design.pdf, qjournal-design.pdf, qjournal-design.pdf, 
> qjournal-design.pdf, qjournal-design.tex, qjournal-design.tex
>
>
> Currently, one of the weak points of the HA design is that it relies on 
> shared storage such as an NFS filer for the shared edit log. One alternative 
> that has been proposed is to depend on BookKeeper, a ZooKeeper subproject 
> which provides a highly available replicated edit log on commodity hardware. 
> This JIRA is to implement another alternative, based on a quorum commit 
> protocol, integrated more tightly in HDFS and with the requirements driven 
> only by HDFS's needs rather than more generic use cases. More details to 
> follow.

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