[ 
https://issues.apache.org/jira/browse/HBASE-1886?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12767411#action_12767411
 ] 

Andrew Purtell commented on HBASE-1886:
---------------------------------------

Ah, now I see the (minor) disconnect. SyncTableAttributes is only for writing 
modified attributes as new HTD in all appropriate regions in META on master 
shutdown. (Misnamed/confusing?) Otherwise what is in ZK is live and canonical 
across rolling restarts, master fail overs, region server restarts, etc. I 
haven't yet gone in and replaced all attribute related references to HTD and 
HCD in master and regionserver with calls into the new ZK methods. That was 
going to be next. Now first up is a second take incorporating all feedback.

> move table and column family attributes to ZK to make them live
> ---------------------------------------------------------------
>
>                 Key: HBASE-1886
>                 URL: https://issues.apache.org/jira/browse/HBASE-1886
>             Project: Hadoop HBase
>          Issue Type: Improvement
>            Reporter: Andrew Purtell
>            Assignee: Andrew Purtell
>             Fix For: 0.20.2, 0.21.0
>
>         Attachments: live_attributes.patch
>
>
> This is a first cut at moving table and column family attributes up to ZK 
> where they can be modified any time without requiring a disable/enable table 
> cycle. Adds methods to ZooKeeperWrapper for support server side. Adds methods 
> to HTableInterface for client side access. Client side talks directly to ZK. 
> The new hierarchy for attributes in ZK is like:
> {noformat}
> /hbase
>   /table
>     /<table-name>
>       /attr
>         /<table-attr-name>
>         /<family-name>
>           /<family-attr-name>
> {noformat}
> As before attribute names and values are byte[], but now that they are hosted 
> in ZK, the path delimiter ('/') cannot be used.
> Attached patch compiles but has not been tested. I put it up for a concept 
> review. Next step before this is functional is to deprecate the attribute 
> related methods on HTD and HCD and chase through the warnings to find all 
> users who should be updated to use the ZK wrapper or new HTable methods 
> instead. And, of course, then add test cases that successfully complete.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to