Err, "an *empty* source file". On Fri, Mar 22, 2013 at 4:33 PM, Nick Dimiduk <[email protected]> wrote:
> 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? >> > > Somewhat tangential to this thread, I think we shouldn't be shy about > deleting old/stale/deprecated code. This should be done on a case-by-case > basis, of course. For example, in this case, maybe the snapshot > functionality will evolve such that the CopyTable interface and semantics > become a pure subset of snapshots. At that point, we should absolutely > delete CopyTable as an independent code-path. > > As they say, "an source file ships no bugs". > > Just my 2¢ > -n > > 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 >> > >> >> <[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 >> > >> >> >>> >> > >> >> >> > >> >> > >> >> >> >> -- >> // Jonathan Hsieh (shay) >> // Software Engineer, Cloudera >> // [email protected] >> > >
