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https://issues.apache.org/jira/browse/HBASE-12534?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Liu Shaohui updated HBASE-12534:
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Attachment: HBASE-12534-0.94-v1.diff
[~lhofhansl]
Patch for 0.94
> Wrong region location cache in client after regions are moved
> -------------------------------------------------------------
>
> Key: HBASE-12534
> URL: https://issues.apache.org/jira/browse/HBASE-12534
> Project: HBase
> Issue Type: Bug
> Affects Versions: 2.0.0
> Reporter: Liu Shaohui
> Assignee: Liu Shaohui
> Priority: Critical
> Labels: client
> Attachments: HBASE-12534-0.94-v1.diff, HBASE-12534-v1.diff
>
>
> In our 0.94 hbase cluster, we found that client got wrong region location
> cache and did not update it after a region is moved to another regionserver.
> The reason is wrong client config and bug in RpcRetryingCaller of hbase
> client.
> The rpc configs are following:
> {code}
> hbase.rpc.timeout=1000
> hbase.client.pause=200
> hbase.client.operation.timeout=1200
> {code}
> But the client retry number is 3
> {code}
> hbase.client.retries.number=3
> {code}
> Assumed that a region is at regionserver A before, and then it is moved to
> regionserver B. The client try to make a call to regionserver A and get an
> NotServingRegionException. For the rety number is not 1, the region server
> location cache is not cleaned. See: RpcRetryingCaller.java#141 and
> RegionServerCallable.java#127
> {code}
> @Override
> public void throwable(Throwable t, boolean retrying) {
> if (t instanceof SocketTimeoutException ||
> ....
> } else if (t instanceof NotServingRegionException && !retrying) {
> // Purge cache entries for this specific region from hbase:meta cache
> // since we don't call connect(true) when number of retries is 1.
> getConnection().deleteCachedRegionLocation(location);
> }
> }
> {code}
> But the call did not retry and throw an SocketTimeoutException for the time
> the call will take is larger than the operation timeout.See
> RpcRetryingCaller.java#152
> {code}
> expectedSleep = callable.sleep(pause, tries + 1);
> // If, after the planned sleep, there won't be enough time left, we
> stop now.
> long duration = singleCallDuration(expectedSleep);
> if (duration > callTimeout) {
> String msg = "callTimeout=" + callTimeout + ", callDuration=" +
> duration +
> ": " + callable.getExceptionMessageAdditionalDetail();
> throw (SocketTimeoutException)(new
> SocketTimeoutException(msg).initCause(t));
> }
> {code}
> At last, the wrong region location will never be not cleaned up .
> [~lhofhansl]
> In hbase 0.94, the MIN_RPC_TIMEOUT in singleCallDuration is 2000 in default,
> which trigger this bug.
> {code}
> private long singleCallDuration(final long expectedSleep) {
> return (EnvironmentEdgeManager.currentTimeMillis() - this.globalStartTime)
> + MIN_RPC_TIMEOUT + expectedSleep;
> }
> {code}
> But there is risk in master code too.
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