[
https://issues.apache.org/jira/browse/HDFS-3077?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13229529#comment-13229529
]
Todd Lipcon commented on HDFS-3077:
-----------------------------------
bq. Sequencing writes between different writers is the hard part. BookKeeper
seems to do this by using ZK to enforce mutual exclusion, which means at its
heart it too relies on a consensus protocol to cope with these tricky failure
cases. This makes it a very legitimate point in the design space, but one that
shares plenty with the proposal here.
Yep -- rather than fully implement ZAB, my initial implementation will also
rely on ZK for writer sequencing. If we want to use this outside the context of
ZK (for example with a different failure detector for the NNs) we could move on
to implement the epoch-sequencing bit of ZAB.
> 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
>
> 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.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
