Changing the subject to reflect current discussion. I think Jean-Marc's work on offline merge would most likely be useful in the context of 0.94.x code base.
Cheers On Thu, Mar 21, 2013 at 4:17 PM, Enis Söztutar <[email protected]> wrote: > 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 > > >> <[email protected]> wrote: > > >> > Vector is because of a very old bad habit ;) I will change that to > > >> ArrayList. > > >> > > > >> > So far I have inlined the scanMetaRegion feature into the Merge, but > > >> > maybe it should be cleaner to put it back in? > > >> > > > >> > Anyway, I will keep the inlined one until everything is cleaned. > > >> > > > >> > 2013/3/21 Enis Söztutar <[email protected]>: > > >> >> The problem around current META scanning is that there is more than > > one > > >> way > > >> >> to do these, and the META layout is exposed. We should refrain from > > >> >> exposing the META details. > > >> >> AFAIK, these do the same thing: > > >> >> MetaReader.Visitor > > >> >> MetaScanner.MetaScannerVisitor, and > > >> >> MetaUtils.ScannerListener > > >> >> > > >> >> More concerning is that the code for managing META is spread over > > >> >> MetaEditor, MetaReader, MetaScanner, MetaUtils, HRegionInfo (and > > maybe > > >> >> more). There are a couple of issues to rework these interfaces, > but I > > >> did > > >> >> not get the chance to work on those. > > >> >> > > >> >> > > >> >> Enis > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> > > >> >> On Thu, Mar 21, 2013 at 2:18 PM, Jean-Daniel Cryans < > > >> [email protected]>wrote: > > >> >> > > >> >>> Mmmm I may have been trigger happy. You could pull back the > > >> >>> ScannerListener and scanMetaRegion. > > >> >>> > > >> >>> BTW, why are you using a Vector instead of ArrayList? > > >> >>> > > >> >>> J-D > > >> >>> > > >> >>> On Thu, Mar 21, 2013 at 2:05 PM, Jean-Marc Spaggiari > > >> >>> <[email protected]> wrote: > > >> >>> > Hi, > > >> >>> > > > >> >>> > In trunk, since HBASE-3171 (Drop ROOT and instead store META > > >> >>> > location(s) directly in ZooKeeper ) there is no more > > >> >>> > MetaUtils.ScannerListener. > > >> >>> > > > >> >>> > In the merge, I used it to retreive all the regions belonging > to a > > >> >>> > specific table, from the META. kind of scan. > > >> >>> > > > >> >>> > // Retrieve the list of regions for this table. > > >> >>> > final List<HRegionInfo> regions = new > > >> Vector<HRegionInfo>(); > > >> >>> > > utils.scanMetaRegion(HRegionInfo.FIRST_META_REGIONINFO, > > new > > >> >>> > MetaUtils.ScannerListener() { > > >> >>> > public boolean processRow(HRegionInfo info) { > > >> >>> > if ((info != null) && > > >> >>> > (Bytes.compareTo(info.getTableName(), tableName) == 0)) { > > >> >>> > regions.add(info); > > >> >>> > } > > >> >>> > return true; > > >> >>> > } > > >> >>> > }); > > >> >>> > > > >> >>> > > > >> >>> > Is there a recommanded way to replace that? The Merge is running > > >> >>> > offline, so I can't do a scan. > > >> >>> > > > >> >>> > Thanks, > > >> >>> > > > >> >>> > JM > > >> >>> > > >> > > >
