I see. I agree that we should throw a warning at least, when someone is trying to merge such regions. Might still be good to have this possibility.
JM 2013/3/16 Kevin O'dell <[email protected]>: > Ted, > > Why would we use that merge tool when hbck will repair that? Should we > throw a warning and tell the user to run repair first? > On Mar 16, 2013 9:17 AM, "Ted" <[email protected]> wrote: > >> 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. >> >> Cheers >> >> 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? >> > >> > JM >> > >> > >> > 2013/3/16 Ted Yu <[email protected]>: >> >> Hi, >> >> 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. >> >> >> >> Thanks >>
