[
https://issues.apache.org/jira/browse/ZOOKEEPER-1016?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13008575#comment-13008575
]
Suresh Srinivas commented on ZOOKEEPER-1016:
--------------------------------------------
+1 on Dhruba's idea of storing editlog in bookkeeper.
Other reasons for doing that:
- Unless you have multiple standby nodes, a primary has to keep an external
copy of edits. The reason is, one might be upgrading a backup node and without
the external copy, all the copies of edits are only on the primary. A hardware
failure on primary could result in loss of edits.
- BookKeeper is a better solution for keeping a "highly available" copy of
edits Vs keeping it highly available on NFS servers. Further bookkeeper can
guarantee writes that an NFS server may not be able to.
> TeaKeeper: Hot standby support using bookkeeper
> -----------------------------------------------
>
> Key: ZOOKEEPER-1016
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-1016
> Project: ZooKeeper
> Issue Type: Improvement
> Reporter: Ivan Kelly
> Assignee: Ivan Kelly
> Priority: Minor
> Attachments: tledger.pdf
>
>
> Currently Bookkeeper provides functionality for cold backups. If the entity
> logging to bookkeeper fails, its replacement must recover the ledgers which
> had been used for backup before becoming available. This is acceptable in
> some cases, such as HBase Wals where a small delay in recovery only results
> in a small percentage of data being unavailable.
> However, systems such as the HDFS namenode, this delay can be unacceptable,
> such as cases where data is being served to customers. Secondary namenodes
> should be ready to go the instant the primary goes down.
> TeaKeeper proposes a wrapper library around Bookkeeper providing T-Junction
> like functionality for logging. It also provides for primary/secondary
> election and automated hot failover.
> HDFS namenode is primary target of this work.
> The attached design doc contains more details.
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira
