-Re: review request: HBASE-7403 Online Merge
Ted 2013-03-16, 13:17
Chunhui replied to this question on review board.
Basically the force option is to repair overlapping regions or table with hole in its regions.
Personally I think online merge should detect merging regions with hole in between them and not require force flag in that case because logically they're adjacent.
On Mar 16, 2013, at 5:52 AM, Jean-Marc Spaggiari <[EMAIL PROTECTED]> wrote:
> Hi Ted,
> I jut gave it a look.
> I have updated it on the RB.
> Overall, this is very good and I'm eager to see that integrated! I'm
> waiting for this feature since the beginning ;)
> Regarding non adjacent regions merge? Will the system still be
> consistent after that? Or will hbck report some regions overlaps?
> 2013/3/16 Ted Yu <[EMAIL PROTECTED]>:
>> On behalf of Chunhui, I am requesting review for HBASE-7403 Online Merge.
>> This JIRA was created 3 months ago.
>> Chunhui has responded to review comments very promptly, including a major
>> rewrite around the time split transaction was rewritten.
>> This feature has widely been requested. I feel the patch is mostly ready to
>> go in.
>> Here is brief recap of the steps.
>> Process of merging two regions:
>> a.client sends RPC (dispatch merging regions) to master
>> b.master moves the regions together (on the regionserver where the more
>> heavily loaded region resided)
>> c.master sends RPC (merge regions) to this regionserver
>> d.Regionserver executes the region merge transaction in the thread pool
>> I think step b is a nice simplification for the problem. In previous
>> versions of the patch, the two merging regions stay on respective servers
>> which required more complex coordination through zookeeper.
>> High level comment as well as detailed review are both welcome.