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https://issues.apache.org/jira/browse/HBASE-16138?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15380271#comment-15380271
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Joseph commented on HBASE-16138:
--------------------------------
I think that shutting down region servers is not as much of an issue, because
the Replication Table only has to be available to register the offsets in WAL
file replication. If the cluster is going down and Replication Table dies first
we simply prevent the RS's from replicating or registering new logs. Thus they
will be blocked, but replication should not lose any data when we eventually
restart the cluster.
> Cannot open regions after non-graceful shutdown due to deadlock with
> Replication Table
> --------------------------------------------------------------------------------------
>
> Key: HBASE-16138
> URL: https://issues.apache.org/jira/browse/HBASE-16138
> Project: HBase
> Issue Type: Sub-task
> Components: Replication
> Reporter: Joseph
> Assignee: Joseph
> Priority: Critical
>
> If we shutdown an entire HBase cluster and attempt to start it back up, we
> have to run the WAL pre-log roll that occurs before opening up a region. Yet
> this pre-log roll must record the new WAL inside of ReplicationQueues. This
> method call ends up blocking on
> TableBasedReplicationQueues.getOrBlockOnReplicationTable(), because the
> Replication Table is not up yet. And we cannot assign the Replication Table
> because we cannot open any regions. This ends up deadlocking the entire
> cluster whenever we lose Replication Table availability.
> There are a few options that we can do, but none of them seem very good:
> 1. Depend on Zookeeper-based Replication until the Replication Table becomes
> available
> 2. Have a separate WAL for System Tables that does not perform any
> replication (see discussion at HBASE-14623)
> Or just have a seperate WAL for non-replicated vs replicated
> regions
> 3. Record the WAL log in the ReplicationQueue asynchronously (don't block
> opening a region on this event), which could lead to inconsistent Replication
> state
> The stacktrace:
>
> org.apache.hadoop.hbase.replication.regionserver.ReplicationSourceManager.recordLog(ReplicationSourceManager.java:376)
>
> org.apache.hadoop.hbase.replication.regionserver.ReplicationSourceManager.preLogRoll(ReplicationSourceManager.java:348)
>
> org.apache.hadoop.hbase.replication.regionserver.Replication.preLogRoll(Replication.java:370)
>
> org.apache.hadoop.hbase.regionserver.wal.FSHLog.tellListenersAboutPreLogRoll(FSHLog.java:637)
>
> org.apache.hadoop.hbase.regionserver.wal.FSHLog.rollWriter(FSHLog.java:701)
>
> org.apache.hadoop.hbase.regionserver.wal.FSHLog.rollWriter(FSHLog.java:600)
>
> org.apache.hadoop.hbase.regionserver.wal.FSHLog.<init>(FSHLog.java:533)
>
> org.apache.hadoop.hbase.wal.DefaultWALProvider.getWAL(DefaultWALProvider.java:132)
>
> org.apache.hadoop.hbase.wal.RegionGroupingProvider.getWAL(RegionGroupingProvider.java:186)
>
> org.apache.hadoop.hbase.wal.RegionGroupingProvider.getWAL(RegionGroupingProvider.java:197)
> org.apache.hadoop.hbase.wal.WALFactory.getWAL(WALFactory.java:240)
>
> org.apache.hadoop.hbase.regionserver.HRegionServer.getWAL(HRegionServer.java:1883)
>
> org.apache.hadoop.hbase.regionserver.handler.OpenRegionHandler.openRegion(OpenRegionHandler.java:363)
>
> org.apache.hadoop.hbase.regionserver.handler.OpenRegionHandler.process(OpenRegionHandler.java:129)
>
> org.apache.hadoop.hbase.executor.EventHandler.run(EventHandler.java:129)
>
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
>
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> java.lang.Thread.run(Thread.java:745)
> Does anyone have any suggestions/ideas/feedback?
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