I think we shouldn't remove the offline tools at this time (perhaps not even at a future time - topic for another day) but a refactor that cleans things up would be good.
On Friday, March 22, 2013, Enis Söztutar wrote: > CopyTable and Snapshots are very useful for backup, while merge and split > are only relevant if the table is serving reads and writes. I can see > having some tools for helping with cases where HBase cannot recover, but > apart from that, normal Hbase operations should not need offline splits or > merges. > > I am not suggesting to remove it now, but if we get online merges rock > solid, we can reevaluate. > > Enis > > > On Fri, Mar 22, 2013 at 9:31 AM, Ted Yu <[email protected]> wrote: > > > Point taken. > > > > But I don't think previous discussion was about removing offline merge. > > > > On Fri, Mar 22, 2013 at 8:19 AM, Jonathan Hsieh <[email protected]> > wrote: > > > > > Let me offer a counter argument. The offline splitting code is still > > > present even though online splitting isn't the problem it used to be. > We > > > actually added an extenal wal replayer even though we have wal replay > in > > > our normal recovery path. Copy table still exists even though > snapshots > > > and snapshot export exists. Would we consider removing these? > > > > > > IMO, until online merge has been proven and hardened (gone through few > > > releases and folk using) I don't feel comfortable removing it. > > > > > > Jon. > > > > > > On Thu, Mar 21, 2013 at 7:07 PM, Jean-Marc Spaggiari < > > > [email protected]> wrote: > > > > > > > Hi Enis, > > > > > > > > I totaly agree. But even if online merge are available, maybe offline > > > > merges can still usefull in case the cluster is down for maintenance, > > > > or because there is any issue to start it, or anything else? We have > > > > it, so we should maybe try to keep it? > > > > > > > > JM > > > > > > > > 2013/3/21 Enis Söztutar <[email protected]>: > > > > > Thanks J-M. > > > > > > > > > > What I am trying to understand is that whether we should cut the > cord > > > for > > > > > offline merge once online is working. If you think about it, there > > > should > > > > > not be a need to merge offline tables. > > > > > > > > > > Enis > > > > > > > > > > > > > > > On Thu, Mar 21, 2013 at 3:16 PM, Jean-Marc Spaggiari < > > > > > [email protected]> wrote: > > > > > > > > > >> Offline merge is already there and working fine. > > > > >> > > > > >> The usecase here was to retreive all the regions for a given table > > to > > > > >> merge them 2 by 2, offline. > > > > >> > > > > >> It's working fine, but since the Meta rework it's not working > > anymore > > > > >> and I'm trying to rebase the patch. > > > > >> > > > > >> Like J-D is saying, yes, it's used only in the offline merge... > And > > > > >> since the online merge is coming, I think it's cleaner to keep the > > > > >> code in the offline merge since it will disapear soon, but in the > > > > >> meantime, at least, we will have the offline one. > > > > >> > > > > >> JM > > > > >> > > > > >> 2013/3/21 Enis Söztutar <[email protected]>: > > > > >> > What is the use case behind offline merge? Is it because we > cannot > > > do > > > > >> > online merge yet? If we can get HBASE-7403 in, is there still > need > > > to > > > > >> > support offline merge? > > > > >> > > > > > >> > Enis > > > > >> > > > > > >> > > > > > >> > On Thu, Mar 21, 2013 at 2:56 PM, Jean-Daniel Cryans < > > > > [email protected] > > > > >> >wrote: > > > > >> > > > > > >> >> As far as I can tell, only the merge code uses MetaUtils to do > > > > offline > > > > >> >> work. If this is the code you are in then pull it back into > > > MetaUtils > > > > >> >> I think. > > > > >> >> > > > > >> >> J-D > > > > >> >> > > > > >> >> On Thu, Mar 21, 2013 at 2:44 PM, Jean-Marc Spaggiari > > > > > -- Best regards, - Andy Problems worthy of attack prove their worth by hitting back. - Piet Hein (via Tom White)
