hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ryan rawson (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HBASE-1730) Near-instantaneous online schema and table state updates
Date Thu, 10 Mar 2011 23:57:59 GMT

    [ 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

Mime
View raw message