w.r.t. querying compaction status, please take a look at the following method in HBaseAdmin:
public CompactionState getCompactionState(final TableName tableName) For triggering major compaction on selected region, see: public void majorCompactRegion(final byte[] regionName) Cheers On Fri, Nov 14, 2014 at 11:49 AM, Shahab Yunus <[email protected]> wrote: > I see. Thanks. > > So we can in a way automate this resolution by invoking major compaction > programmatically for the 2 regions under process (or we need to do the > whole table?). Point being, that the merge tool, once identifies that it is > stuck in a polling loop, can invoke major compaction on the 2 regions or > table and then try again. Does it make sense? Plausible solution? We do > know that this merging, although automated, will still be run in a > controlled manner so chances of overstepping or synchronization issues on > the current table should not occur. > > But ow the question is that majorCompact is also an aync operation. So how > and when to know it has finished? :) > > Regards, > Shahab > > On Fri, Nov 14, 2014 at 2:34 PM, Ted Yu <[email protected]> wrote: > > > This means that yesterday's compaction was not major compaction. > > > > When references get in the way of merging regions, you know that it is > time > > for major compaction. > > > > Cheers > > > > On Fri, Nov 14, 2014 at 11:31 AM, Shahab Yunus <[email protected]> > > wrote: > > > > > After major compacting the references were freed for the above > mentioned > > > regions and then the merge_region command succeeded and they got > merged. > > > Hmmm. > > > > > > Regards, > > > Shahab > > > > > > On Fri, Nov 14, 2014 at 2:08 PM, Shahab Yunus <[email protected]> > > > wrote: > > > > > > > Digging deeper into the code, I came across this (this is from > > > > CatalogJanitor#cleanMergeRegion): > > > > > > > > > > > > ... > > > > > > > > ... > > > > > > > > HFileArchiver.archiveRegion < > > > > > > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.hbase/hbase-server/0.96.0-hadoop2/org/apache/hadoop/hbase/backup/HFileArchiver.java#HFileArchiver.archiveRegion%28org.apache.hadoop.conf.Configuration%2Corg.apache.hadoop.fs.FileSystem%2Corg.apache.hadoop.hbase.HRegionInfo%29 > > >(this.services > > > < > > > > > > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.hbase/hbase-server/0.96.0-hadoop2/org/apache/hadoop/hbase/master/CatalogJanitor.java#CatalogJanitor.0services > > >.getConfiguration > > > < > > > > > > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.hbase/hbase-client/0.96.0-hadoop2/org/apache/hadoop/hbase/Server.java#Server.getConfiguration%28%29 > > >(), > > > fs, regionA); > > > > > > > > HFileArchiver.archiveRegion < > > > > > > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.hbase/hbase-server/0.96.0-hadoop2/org/apache/hadoop/hbase/backup/HFileArchiver.java#HFileArchiver.archiveRegion%28org.apache.hadoop.conf.Configuration%2Corg.apache.hadoop.fs.FileSystem%2Corg.apache.hadoop.hbase.HRegionInfo%29 > > >(this.services > > > < > > > > > > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.hbase/hbase-server/0.96.0-hadoop2/org/apache/hadoop/hbase/master/CatalogJanitor.java#CatalogJanitor.0services > > >.getConfiguration > > > < > > > > > > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.hbase/hbase-client/0.96.0-hadoop2/org/apache/hadoop/hbase/Server.java#Server.getConfiguration%28%29 > > >(), > > > fs, regionB); > > > > > > > > MetaEditor.deleteMergeQualifiers < > > > > > > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.hbase/hbase-server/0.96.0-hadoop2/org/apache/hadoop/hbase/catalog/MetaEditor.java#MetaEditor.deleteMergeQualifiers%28org.apache.hadoop.hbase.catalog.CatalogTracker%2Corg.apache.hadoop.hbase.HRegionInfo%29 > > >(server > > > < > > > > > > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.hbase/hbase-server/0.96.0-hadoop2/org/apache/hadoop/hbase/master/CatalogJanitor.java#CatalogJanitor.0server > > >.getCatalogTracker > > > < > > > > > > http://grepcode.com/file/repo1.maven.org/maven2/org.apache.hbase/hbase-client/0.96.0-hadoop2/org/apache/hadoop/hbase/Server.java#Server.getCatalogTracker%28%29 > > >(), > > > mergedRegion); > > > > > > > > return true; > > > > > > > > > > > > Do you think it is ok if we face this issue then we forcibly archive > > and > > > > clean the regions ? > > > > > > > > Regards, > > > > Shahab > > > > > > > > On Fri, Nov 14, 2014 at 1:10 PM, Shahab Yunus < > [email protected]> > > > > wrote: > > > > > > > >> Yesterday, I believe. > > > >> > > > >> Regards, > > > >> Shahab > > > >> > > > >> On Fri, Nov 14, 2014 at 1:07 PM, Ted Yu <[email protected]> > wrote: > > > >> > > > >>> Shahab: > > > >>> When was the last time compaction was run on this table ? > > > >>> > > > >>> Cheers > > > >>> > > > >>> On Fri, Nov 14, 2014 at 9:58 AM, Shahab Yunus < > > [email protected]> > > > >>> wrote: > > > >>> > > > >>> > I see. Thanks. > > > >>> > > > > >>> > And if the region indeed has references, then can we somehow > > forcibly > > > >>> > remove them? Is this even possible (if not advisable)? Basically > > what > > > >>> I am > > > >>> > trying to ask is that let us say we do hit this scenario and we > > know > > > >>> it is > > > >>> > OK to go ahead and merge. What steps can we follow after > detection > > of > > > >>> such > > > >>> > unwanted references. > > > >>> > > > > >>> > Regards, > > > >>> > Shahab > > > >>> > > > > >>> > On Fri, Nov 14, 2014 at 12:50 PM, Ted Yu <[email protected]> > > > wrote: > > > >>> > > > > >>> > > For automated detection of such scenario, you can reference the > > > code > > > >>> in > > > >>> > > CatalogJanitor#cleanMergeRegion(): > > > >>> > > > > > >>> > > regionFs = HRegionFileSystem.openRegionFromFileSystem( > > > >>> > > > > > >>> > > this.services.getConfiguration(), fs, tabledir, > > > >>> mergedRegion, > > > >>> > > true > > > >>> > > ); > > > >>> > > > > > >>> > > ... > > > >>> > > > > > >>> > > Then regionFs.hasReferences(htd) would tell you whether the > > > >>> underlying > > > >>> > > region has reference files. > > > >>> > > Cheers > > > >>> > > > > > >>> > > On Fri, Nov 14, 2014 at 9:39 AM, Shahab Yunus < > > > >>> [email protected]> > > > >>> > > wrote: > > > >>> > > > > > >>> > > > No. Not that I can recall but I can check. > > > >>> > > > > > > >>> > > > From resolution perspective, is there any way we can resolve > > > this. > > > >>> More > > > >>> > > > importantly, anyway we can automate the resolution, if we run > > > into > > > >>> such > > > >>> > > > issues in future? 'Cleaning the qualifier', that is. > > > >>> > > > > > > >>> > > > Regards, > > > >>> > > > Shahab > > > >>> > > > > > > >>> > > > On Fri, Nov 14, 2014 at 12:12 PM, Ted Yu < > [email protected]> > > > >>> wrote: > > > >>> > > > > > > >>> > > > > One possibility was that region > > > 7373f75181c71eb5061a6673cee15931 > > > >>> was > > > >>> > > > > involved in some hbase snapshot. > > > >>> > > > > > > > >>> > > > > Was the underlying table being snapshotted in recent past ? > > > >>> > > > > > > > >>> > > > > Cheers > > > >>> > > > > > > > >>> > > > > On Fri, Nov 14, 2014 at 9:05 AM, Shahab Yunus < > > > >>> > [email protected]> > > > >>> > > > > wrote: > > > >>> > > > > > > > >>> > > > > > Thanks again. > > > >>> > > > > > > > > >>> > > > > > But I have been polling for a while and it still doesn't > > > >>> merge. I > > > >>> > > mean > > > >>> > > > > this > > > >>> > > > > > particular region example that I sent you, I am trying to > > > >>> merge it > > > >>> > > > since > > > >>> > > > > > yesterday. I ran the polling-base code all night and I > have > > > to > > > >>> kill > > > >>> > > it. > > > >>> > > > > > Then in the morning, I tried manual merging through hbase > > > >>> shell and > > > >>> > > it > > > >>> > > > > > still doesn't merge. Note that the current polling logic > > > >>> doesnot > > > >>> > try > > > >>> > > to > > > >>> > > > > > call merge again. It just checks the region size. > > > >>> > > > > > > > > >>> > > > > > So how to clean it then? Or actually make it merge? Plus > is > > > >>> this > > > >>> > > > > something > > > >>> > > > > > expected (a region keeping a reference)? How can we avoid > > it? > > > >>> > > > > > > > > >>> > > > > > Note that this is not limited to this table only. We are > > > seeing > > > >>> > this > > > >>> > > in > > > >>> > > > > > other regions of other tables as well. Are we merging too > > > fast? > > > >>> > > > > > > > > >>> > > > > > > > > >>> > > > > > > > > >>> > > > > > Regards, > > > >>> > > > > > Shahab > > > >>> > > > > > > > > >>> > > > > > On Fri, Nov 14, 2014 at 11:58 AM, Ted Yu < > > > [email protected]> > > > >>> > > wrote: > > > >>> > > > > > > > > >>> > > > > > > Polling as you described is fine. > > > >>> > > > > > > > > > >>> > > > > > > catalogJanitor.cleanMergeQualifier() is called by > > > >>> > > > > > > DispatchMergingRegionHandler. > > > >>> > > > > > > > > > >>> > > > > > > If clean was successful, you would see the following: > > > >>> > > > > > > > > > >>> > > > > > > LOG.debug("Deleting region " + > > > >>> > > regionA.getRegionNameAsString() > > > >>> > > > + > > > >>> > > > > " > > > >>> > > > > > > and " > > > >>> > > > > > > > > > >>> > > > > > > + regionB.getRegionNameAsString() > > > >>> > > > > > > > > > >>> > > > > > > + " from fs because merged region no longer > > holds > > > >>> > > > > references"); > > > >>> > > > > > > > > > >>> > > > > > > Assuming there was no log below in your master log: > > > >>> > > > > > > > > > >>> > > > > > > LOG.error("Merged region " + > > > >>> region.getRegionNameAsString() > > > >>> > > > > > > > > > >>> > > > > > > + " has only one merge qualifier in META."); > > > >>> > > > > > > > > > >>> > > > > > > It would be the case that > > 7373f75181c71eb5061a6673cee15931 > > > >>> still > > > >>> > > had > > > >>> > > > > > > reference file. > > > >>> > > > > > > > > > >>> > > > > > > Cheers > > > >>> > > > > > > > > > >>> > > > > > > On Fri, Nov 14, 2014 at 8:35 AM, Shahab Yunus < > > > >>> > > > [email protected]> > > > >>> > > > > > > wrote: > > > >>> > > > > > > > > > >>> > > > > > > > Hi Ted. > > > >>> > > > > > > > > > > >>> > > > > > > > The log bit is below at the end of the email. This is > > the > > > >>> > command > > > >>> > > > to > > > >>> > > > > > > merge > > > >>> > > > > > > > that I gave just now through hbase shell. forcible > was > > > >>> false > > > >>> > but > > > >>> > > it > > > >>> > > > > > > behaves > > > >>> > > > > > > > similarly if forcible is true too. This is from > master > > > log. > > > >>> > > Indeed > > > >>> > > > > the > > > >>> > > > > > > > region merging was skipped! What does this mean? Data > > > >>> seems to > > > >>> > be > > > >>> > > > > > intact > > > >>> > > > > > > > for this table. > > > >>> > > > > > > > > > > >>> > > > > > > > Just to give you a background. This table was first > > merge > > > >>> by > > > >>> > the > > > >>> > > > auto > > > >>> > > > > > > mated > > > >>> > > > > > > > java application. What we are doing is that we are > > > merging > > > >>> > tables > > > >>> > > > > > > > programmatically. As the HBaseAdmin.mergeRegions > calls > > i > > > >>> async, > > > >>> > > we > > > >>> > > > > poll > > > >>> > > > > > > for > > > >>> > > > > > > > the number of regions getting lowered after this > merge > > > >>> call. > > > >>> > The > > > >>> > > > > > > > application hangs and continues polling for ever as > the > > > >>> > previous > > > >>> > > > > merge > > > >>> > > > > > > > didn't happen. > > > >>> > > > > > > > > > > >>> > > > > > > > In this poll loop, we do get the number of regions > by a > > > >>> fresh > > > >>> > > call > > > >>> > > > to > > > >>> > > > > > > > HBaseAdmin.getTableRegions(tableName).getSize(). > > > >>> > > > > > > > > > > >>> > > > > > > > What are these merge qualifiers and what are we doing > > > >>> wrong or > > > >>> > > > should > > > >>> > > > > > do? > > > >>> > > > > > > > > > > >>> > > > > > > > In the polling loop we can somehow retry merge again? > > But > > > >>> how > > > >>> > can > > > >>> > > > we > > > >>> > > > > > > know, > > > >>> > > > > > > > that we need to call merge again as it works for some > > > >>> regions. > > > >>> > Is > > > >>> > > > the > > > >>> > > > > > > table > > > >>> > > > > > > > meta corrupted for some reason by the above logic? > > > >>> > > > > > > > > > > >>> > > > > > > > Thanks a lot. > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > >>> > > > > > > >>> > > > > >>> > > > > ------------------------------------------------------------------------ > > > >>> > > > > > > > > > > >>> > > > > > > > 2014-11-14 11:25:02,643 INFO > > > >>> org.apache.zookeeper.ZooKeeper: > > > >>> > > > Session: > > > >>> > > > > > > > 0x348c7017707236b closed > > > >>> > > > > > > > 2014-11-14 11:25:02,643 INFO > > > >>> org.apache.zookeeper.ClientCnxn: > > > >>> > > > > > EventThread > > > >>> > > > > > > > shut down > > > >>> > > > > > > > 2014-11-14 11:25:02,645 INFO > > > >>> org.apache.zookeeper.ZooKeeper: > > > >>> > > > > Initiating > > > >>> > > > > > > > client connection, > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > >>> > > > > > > > >>> > > > > > > >>> > > > > > >>> > > > > >>> > > > > > > connectString=ip-1010019.ec2.internal:2181,ip-1010017.ec2.internal:2181,ip-1010018.ec2.internal:2181 > > > >>> > > > > > > > sessionTimeout=60000 > > > >>> > > > > watcher=catalogtracker-on-hconnection-0x47d865f2, > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > >>> > > > > > > > >>> > > > > > > >>> > > > > > >>> > > > > >>> > > > > > > quorum=ip-1010019.ec2.internal:2181,ip-1010017.ec2.internal:2181,ip-1010018.ec2.internal:2181, > > > >>> > > > > > > > baseZNode=/hbase > > > >>> > > > > > > > 2014-11-14 11:25:02,645 INFO > > > >>> > > > > > > > > org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper: > > > >>> Process > > > >>> > > > > > > > identifier=catalogtracker-on-hconnection-0x47d865f2 > > > >>> connecting > > > >>> > to > > > >>> > > > > > > ZooKeeper > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > >>> > > > > > > > >>> > > > > > > >>> > > > > > >>> > > > > >>> > > > > > > ensemble=ip-1010019.ec2.internal:2181,ip-1010017.ec2.internal:2181,ip-1010018.ec2.internal:2181 > > > >>> > > > > > > > 2014-11-14 11:25:02,645 INFO > > > >>> org.apache.zookeeper.ClientCnxn: > > > >>> > > > Opening > > > >>> > > > > > > > socket connection to server > > > >>> > ip-1010018.ec2.internal/1010019:2181. > > > >>> > > > > Will > > > >>> > > > > > > not > > > >>> > > > > > > > attempt to authenticate using SASL (unknown error) > > > >>> > > > > > > > 2014-11-14 11:25:02,646 INFO > > > >>> org.apache.zookeeper.ClientCnxn: > > > >>> > > > Socket > > > >>> > > > > > > > connection established to > > > >>> ip-1010018.ec2.internal/1010019:2181, > > > >>> > > > > > > initiating > > > >>> > > > > > > > session > > > >>> > > > > > > > 2014-11-14 11:25:02,648 INFO > > > >>> org.apache.zookeeper.ClientCnxn: > > > >>> > > > Session > > > >>> > > > > > > > establishment complete on server > > > >>> > > > > ip-1010018.ec2.internal/1010019:2181, > > > >>> > > > > > > > sessionid = 0x348c7017707236c, negotiated timeout = > > 60000 > > > >>> > > > > > > > 2014-11-14 11:25:02,703 INFO > > > >>> org.apache.zookeeper.ZooKeeper: > > > >>> > > > Session: > > > >>> > > > > > > > 0x348c7017707236c closed > > > >>> > > > > > > > 2014-11-14 11:25:02,703 INFO > > > >>> org.apache.zookeeper.ClientCnxn: > > > >>> > > > > > EventThread > > > >>> > > > > > > > shut down > > > >>> > > > > > > > 2014-11-14 11:25:30,713 INFO > > > >>> > > > > > > > > > > >>> > > > > > > >>> > org.apache.hadoop.hbase.master.handler.DispatchMergingRegionHandler: > > > >>> > > > > > Skip > > > >>> > > > > > > > merging regions > > > >>> > > > > > > > > > > >>> TABLE_NAME,,1415915112497.7373f75181c71eb5061a6673cee15931., > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > >>> > > > > > > > >>> > > > > > > >>> > > > > > >>> > > > > >>> > > > > > > TABLE_NAME,\x02\xFA\xF0\x80\x00\x00\x01I\xAA\xD5\x87\xA8\x19\x99\x99\x99\x99\x99\x99\x90,1415910559217.43f4d3685d113d3ae18eea9f189de096., > > > >>> > > > > > > > because region 7373f75181c71eb5061a6673cee15931 has > > merge > > > >>> > > qualifier > > > >>> > > > > > > > 2014-11-14 11:25:41,383 INFO > > > >>> org.apache.zookeeper.ZooKeeper: > > > >>> > > > > Initiating > > > >>> > > > > > > > client connection, > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > >>> > > > > > > > >>> > > > > > > >>> > > > > > >>> > > > > >>> > > > > > > connectString=ip-1010019.ec2.internal:2181,ip-1010017.ec2.internal:2181,ip-1010018.ec2.internal:2181 > > > >>> > > > > > > > sessionTimeout=60000 > > > >>> > > > > watcher=catalogtracker-on-hconnection-0x47d865f2, > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > >>> > > > > > > > >>> > > > > > > >>> > > > > > >>> > > > > >>> > > > > > > quorum=ip-1010019.ec2.internal:2181,ip-1010017.ec2.internal:2181,ip-1010018.ec2.internal:2181, > > > >>> > > > > > > > baseZNode=/hbase > > > >>> > > > > > > > 2014-11-14 11:25:41,384 INFO > > > >>> > > > > > > > > org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper: > > > >>> Process > > > >>> > > > > > > > identifier=catalogtracker-on-hconnection-0x47d865f2 > > > >>> connecting > > > >>> > to > > > >>> > > > > > > ZooKeeper > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > >>> > > > > > > > >>> > > > > > > >>> > > > > > >>> > > > > >>> > > > > > > ensemble=ip-1010019.ec2.internal:2181,ip-1010017.ec2.internal:2181,ip-1010018.ec2.internal:2181 > > > >>> > > > > > > > 2014-11-14 11:25:41,384 INFO > > > >>> org.apache.zookeeper.ClientCnxn: > > > >>> > > > Opening > > > >>> > > > > > > > socket connection to server > > > >>> > ip-1010018.ec2.internal/1010019:2181. > > > >>> > > > > Will > > > >>> > > > > > > not > > > >>> > > > > > > > attempt to authenticate using SASL (unknown error) > > > >>> > > > > > > > 2014-11-14 11:25:41,386 INFO > > > >>> org.apache.zookeeper.ClientCnxn: > > > >>> > > > Socket > > > >>> > > > > > > > connection established to > > > >>> ip-1010018.ec2.internal/1010019:2181, > > > >>> > > > > > > initiating > > > >>> > > > > > > > session > > > >>> > > > > > > > 2014-11-14 11:25:41,389 INFO > > > >>> org.apache.zookeeper.ClientCnxn: > > > >>> > > > Session > > > >>> > > > > > > > establishment complete on server > > > >>> > > > > ip-1010018.ec2.internal/1010019:2181, > > > >>> > > > > > > > sessionid = 0x348c7017707236e, negotiated timeout = > > 60000 > > > >>> > > > > > > > 2014-11-14 11:25:41,397 INFO > > > >>> org.apache.zookeeper.ZooKeeper: > > > >>> > > > Session: > > > >>> > > > > > > > 0x348c7017707236e closed > > > >>> > > > > > > > 2014-11-14 11:25:41,398 INFO > > > >>> org.apache.zookeeper.ClientCnxn: > > > >>> > > > > > EventThread > > > >>> > > > > > > > shut down > > > >>> > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > >>> > > > > > > > >>> > > > > > > >>> > > > > > >>> > > > > >>> > > > > > > ------------------------------------------------------------------------------------------------------------------------------------ > > > >>> > > > > > > > > > > >>> > > > > > > > Regards, > > > >>> > > > > > > > Shahab > > > >>> > > > > > > > > > > >>> > > > > > > > On Fri, Nov 14, 2014 at 10:56 AM, Ted Yu < > > > >>> [email protected]> > > > >>> > > > > wrote: > > > >>> > > > > > > > > > > >>> > > > > > > > > Looking at DispatchMergingRegionHandler, it does > some > > > >>> check > > > >>> > > > before > > > >>> > > > > > > > > initiating the merge. > > > >>> > > > > > > > > e.g.: > > > >>> > > > > > > > > > > > >>> > > > > > > > > LOG.info("Skip merging regions " + > > > >>> > > > > > > region_a.getRegionNameAsString() > > > >>> > > > > > > > > > > > >>> > > > > > > > > + ", " + > region_b.getRegionNameAsString() + > > > ", > > > >>> > > because > > > >>> > > > > > > region " > > > >>> > > > > > > > > > > > >>> > > > > > > > > + (regionAHasMergeQualifier ? > > > >>> > > > region_a.getEncodedName() : > > > >>> > > > > > > > > region_b > > > >>> > > > > > > > > > > > >>> > > > > > > > > .getEncodedName()) + " has merge > > > >>> qualifier"); > > > >>> > > > > > > > > > > > >>> > > > > > > > > Can you take a look at master log around the time > > merge > > > >>> > request > > > >>> > > > was > > > >>> > > > > > > > issued > > > >>> > > > > > > > > to see if you can get some clue ? > > > >>> > > > > > > > > > > > >>> > > > > > > > > Cheers > > > >>> > > > > > > > > > > > >>> > > > > > > > > On Fri, Nov 14, 2014 at 6:41 AM, Shahab Yunus < > > > >>> > > > > > [email protected]> > > > >>> > > > > > > > > wrote: > > > >>> > > > > > > > > > > > >>> > > > > > > > > > The documentation of online merge tool > > (merge_region) > > > >>> > states > > > >>> > > > that > > > >>> > > > > > if > > > >>> > > > > > > we > > > >>> > > > > > > > > > forcibly merge regions (by setting the 3rd > > attribute > > > as > > > >>> > true) > > > >>> > > > > then > > > >>> > > > > > it > > > >>> > > > > > > > can > > > >>> > > > > > > > > > create overlapping regions. if this happens then > > will > > > >>> this > > > >>> > > > render > > > >>> > > > > > the > > > >>> > > > > > > > > > region or table unusable or it is just a > > performance > > > >>> hit? I > > > >>> > > > mean > > > >>> > > > > > how > > > >>> > > > > > > > > bigger > > > >>> > > > > > > > > > of a deal it is? > > > >>> > > > > > > > > > > > > >>> > > > > > > > > > Actually, we are merging regions using the > > > >>> programmatic API > > > >>> > > for > > > >>> > > > > > this > > > >>> > > > > > > > and > > > >>> > > > > > > > > > setting this flag ('forcible') as false. But for > > some > > > >>> > tables > > > >>> > > > (we > > > >>> > > > > > > > haven't > > > >>> > > > > > > > > > figured out a pattern yet, data is still > > accessible), > > > >>> merge > > > >>> > > of > > > >>> > > > > > > regions > > > >>> > > > > > > > do > > > >>> > > > > > > > > > not happen at all. Afterwards we tried with this > > > flag = > > > >>> > true, > > > >>> > > > and > > > >>> > > > > > it > > > >>> > > > > > > > > still > > > >>> > > > > > > > > > doesn't merge them. > > > >>> > > > > > > > > > > > > >>> > > > > > > > > > CDH 5.1.0 > > > >>> > > > > > > > > > (Hbase is 0.98.1-cdh5.1.0) > > > >>> > > > > > > > > > > > > >>> > > > > > > > > > Regards, > > > >>> > > > > > > > > > Shahab > > > >>> > > > > > > > > > > > > >>> > > > > > > > > > > > >>> > > > > > > > > > > >>> > > > > > > > > > >>> > > > > > > > > >>> > > > > > > > >>> > > > > > > >>> > > > > > >>> > > > > >>> > > > >> > > > >> > > > > > > > > > >
