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https://issues.apache.org/jira/browse/HBASE-16270?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15403288#comment-15403288
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Robert Yokota edited comment on HBASE-16270 at 8/2/16 3:23 PM:
---------------------------------------------------------------
First, I'm sorry but I won't be able to reproduce this for you. When it
happened, it caused disruption for external and internal customers.
Second, thank you for your patience with my musings as I am out of my depth in
this matter.
My conjecture is that this is happening for primary regions (not secondary
regions). I'm also guessing that it is through a call to
StoreFlusherImpl.commit() concurrent with another StoreFlusherImpl method that
calls updateStoreFiles. For example, here is another line where
HRegion.internalFlushcache() eventually calls StoreFlusherImpl.commit(). Note
that it is called for a primary region, but only if region replicas are turned
on. However, I don't know if it is possible that another call to
StoreFlusherImpl.commit() can be happening concurrently.
https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java#L1234-L1243
was (Author: rayokota):
First, I'm sorry but I won't be able to reproduce this for you. When it
happened, it caused disruption for external and internal customers.
Second, thank you for your patience with my musings as I am out of my depth in
this matter.
My conjecture is that this is happening for primary regions (not secondary
regions). I'm also guessing that it is through concurrent calls to
StoreFlusherImpl.commit(). For example, here is another line where
HRegion.internalFlushcache() eventually calls StoreFlusherImpl.commit(). Note
that it is called for a primary region, but only if region replicas are turned
on. However, I don't know if it is possible that another call to
StoreFlusherImpl.commit() can be happening concurrently.
https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java#L1234-L1243
> When using region replicas, get thousands of occurrences of
> UnexpectedStateException: Current snapshot id is -1
> ---------------------------------------------------------------------------------------------------------------
>
> Key: HBASE-16270
> URL: https://issues.apache.org/jira/browse/HBASE-16270
> Project: HBase
> Issue Type: Bug
> Components: Replication
> Affects Versions: 1.1.2
> Reporter: Robert Yokota
> Attachments: HBASE-16270-branch-1.2.patch, HBASE-16270-master.patch
>
>
> We have an HBase (1.1.2) production cluster with 58 region servers and a
> staging cluster with 6 region servers.
> For both clusters, we enabled region replicas with the following settings:
> hbase.regionserver.storefile.refresh.period = 0
> hbase.region.replica.replication.enabled = true
> hbase.region.replica.replication.memstore.enabled = true
> hbase.master.hfilecleaner.ttl = 3600000
> hbase.master.loadbalancer.class =
> org.apache.hadoop.hbase.master.balancer.StochasticLoadBalancer
> hbase.meta.replica.count = 3
> hbase.regionserver.meta.storefile.refresh.period = 30000
> hbase.region.replica.wait.for.primary.flush = true
> hbase.region.replica.storefile.refresh.memstore.multiplier = 4
> We then altered our HBase tables to have REGION_REPLICATION => 2
> Both clusters got into a state where a few region servers were spewing the
> following error below in the HBase logs. In one instance the error occurred
> over 70K times. At this time, these region servers would see 10x write
> traffic (the hadoop.HBase.RegionServer.Server.writeRequestCount metric) and
> in some instances would crash.
> At the same time, we would see secondary regions move and then go into the
> "reads are disabled" state for extended periods.
> It appears there is a race condition where the DefaultMemStore::clearSnapshot
> method might be called more than once in succession. The first call would set
> snapshotId to -1, but the second call would throw an exception. It seems the
> second call should just return if the snapshotId is already -1, rather than
> throwing an exception.
> Thu Jul 21 08:38:50 UTC 2016,
> RpcRetryingCaller{globalStartTime=1469090201543, pause=100, retries=35},
> org.apache.hadoop.hbase.regionserver.UnexpectedStateException:
> org.apache.hadoop.hbase.regionserver.UnexpectedStateException: Current
> snapshot id is -1,passed 1469085004304
> at
> org.apache.hadoop.hbase.regionserver.DefaultMemStore.clearSnapshot(DefaultMemStore.java:187)
> at
> org.apache.hadoop.hbase.regionserver.HStore.updateStorefiles(HStore.java:1054)
> at
> org.apache.hadoop.hbase.regionserver.HStore.access$500(HStore.java:128)
> at
> org.apache.hadoop.hbase.regionserver.HStore$StoreFlusherImpl.replayFlush(HStore.java:2270)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.replayFlushInStores(HRegion.java:4487)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.replayWALFlushCommitMarker(HRegion.java:4388)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.replayWALFlushMarker(HRegion.java:4191)
> at
> org.apache.hadoop.hbase.regionserver.RSRpcServices.doReplayBatchOp(RSRpcServices.java:776)
> at
> org.apache.hadoop.hbase.regionserver.RSRpcServices.replay(RSRpcServices.java:1655)
> at
> org.apache.hadoop.hbase.protobuf.generated.AdminProtos$AdminService$2.callBlockingMethod(AdminProtos.java:22255)
> at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2114)
> at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:101)
> at
> org.apache.hadoop.hbase.ipc.RpcExecutor.consumerLoop(RpcExecutor.java:130)
> at org.apache.hadoop.hbase.ipc.RpcExecutor$1.run(RpcExecutor.java:107)
> at java.lang.Thread.run(Thread.java:745)
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