[
https://issues.apache.org/jira/browse/HBASE-3604?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13002551#comment-13002551
]
dhruba borthakur commented on HBASE-3604:
-----------------------------------------
I did see this in the master logs (at the time when it decided to reassign the
region from A to B):
{quote}
java.io.IOException: Discovered orphan hlog after split. Maybe HRegionServer
was not dead when we started
at
org.apache.hadoop.hbase.regionserver.wal.HLogSplitter.splitLog(HLogSplitter.java:290)
at
org.apache.hadoop.hbase.regionserver.wal.HLogSplitter.splitLog(HLogSplitter.java:151)
at
org.apache.hadoop.hbase.master.MasterFileSystem.splitLog(MasterFileSystem.java:193)
at
org.apache.hadoop.hbase.master.handler.ServerShutdownHandler.process(ServerShutdownHandler.java:96)
at org.apache.hadoop.hbase.executor.EventHandler.run(EventHandler.java:151)
at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
2011-03-03 05:09:55,551 INFO
org.apache.hadoop.hbase.master.handler.ServerShutdownHandler: Reassigning 64
region(s) that pumahbase024.snc5.facebook.com,60020,1299034310798 was carrying
(skipping 0 regions(s) that are already in transition)
2011-03-03 05:09:55,588 DEBUG org.apache.hadoop.hbase.master.AssignmentManager:
Assigning region XXXXs,aae1476e,1290555944175.c155464b43a3267c4a2778b769026775.
to B.com,60020,1299034311241
> Two region servers think that they own the same region: data loss
> -----------------------------------------------------------------
>
> Key: HBASE-3604
> URL: https://issues.apache.org/jira/browse/HBASE-3604
> Project: HBase
> Issue Type: Bug
> Components: regionserver
> Affects Versions: 0.90.0
> Reporter: dhruba borthakur
> Assignee: dhruba borthakur
>
> I observed this on a 100 node cluster that is constantly doing about 500K
> ops/second.
> The region server on machine A was servicing IOs for a particular region.
> Then the machine went into a bad state where it is ping-able but not
> ssh-able. The master detected that there is a problem with machine A and
> reassigned the region to machine B. The regionserver on machine B opened the
> region and opened all the required HFiles for this region. After two hours,
> the NameNode received a delete request for one of the HFiles from machine A
> and happily renamed the file to HDFS-Trash. After another 3 hours or so, the
> regionserver on machine B tried to read contents from that HFile but failed
> because the file was renamed earlier. The region server on B in now stuck,
> and possible data loss.
> The problems stems from the fact that although the master-and-ZK reassigned
> the region, the old regionserver was not possibly dead.
--
This message is automatically generated by JIRA.
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
