[
https://issues.apache.org/jira/browse/HBASE-1730?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13005415#comment-13005415
]
ryan rawson commented on HBASE-1730:
------------------------------------
this is because we dont have a lot of expertise in managing zk state. there are
no dump tools, no restore tools, etc, etc. It would also make snapshotting a
table harder, since there is now a secondary system to manage separately. By
committing changes to WAL logs then having the regionservers execute those
changes we have a better chance of doing snapshot & restore if, for example,
HBASE-50 came back.
> Near-instantaneous online schema and table state updates
> --------------------------------------------------------
>
> Key: HBASE-1730
> URL: https://issues.apache.org/jira/browse/HBASE-1730
> Project: HBase
> Issue Type: Improvement
> Reporter: Andrew Purtell
> Assignee: stack
> Fix For: 0.92.0
>
> Attachments: 1730-v2.patch, 1730-v3.patch, 1730.patch
>
>
> We should not need to take a table offline to update HCD or HTD.
> One option for that is putting HTDs and HCDs up into ZK, with mirror on disk
> catalog tables to be used only for cold init scenarios, as discussed on IRC.
> In this scheme, regionservers hosting regions of a table would watch
> permanent nodes in ZK associated with that table for schema updates and take
> appropriate actions out of the watcher. In effect, schema updates become
> another item in the ToDo list.
> {{/hbase/tables/<table-name>/schema}}
> Must be associated with a write locking scheme also handled with ZK
> primitives to avoid situations where one concurrent update clobbers another.
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira
