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https://issues.apache.org/jira/browse/HBASE-18005?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16039151#comment-16039151
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huaxiang sun commented on HBASE-18005:
--------------------------------------
Thanks [[email protected]]. The failed unittest TestReplicasClient, I run
locally with my patch on branch-1, it passed. The findbug warning is
complaining
{code}
RV Return value of java.util.concurrent.CountDownLatch.await(long,
TimeUnit) ignored in
org.apache.hadoop.hbase.regionserver.HRegionServer.initializeZooKeeper()
if (this.initLatch != null) {
this.initLatch.await(20, TimeUnit.SECONDS);
}
{code}
This is the existing code which is not touched by this patch. We can check the
return value and log something to get rid of the findbug warning.
> read replica: handle the case that region server hosting both primary replica
> and meta region is down
> -----------------------------------------------------------------------------------------------------
>
> Key: HBASE-18005
> URL: https://issues.apache.org/jira/browse/HBASE-18005
> Project: HBase
> Issue Type: Bug
> Reporter: huaxiang sun
> Assignee: huaxiang sun
> Attachments: HBASE-18005-branch-1-v001.patch,
> HBASE-18005-master-001.patch, HBASE-18005-master-002.patch,
> HBASE-18005-master-003.patch, HBASE-18005-master-004.patch,
> HBASE-18005-master-005.patch, HBASE-18005-master-006.patch
>
>
> Identified one corner case in testing that when the region server hosting
> both primary replica and the meta region is down, the client tries to reload
> the primary replica location from meta table, it is supposed to clean up only
> the cached location for specific replicaId, but it clears caches for all
> replicas. Please see
> https://github.com/apache/hbase/blob/master/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java#L813
> Since it takes some time for regions to be reassigned (including meta
> region), the following may throw exception
> https://github.com/apache/hbase/blob/master/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RpcRetryingCallerWithReadReplicas.java#L173
> This exception needs to be caught and it needs to get cached location (in
> this case, the primary replica's location is not available). If there are
> cached locations for other replicas, it can still go ahead to get stale
> values from secondary replicas.
> With meta replica, it still helps to not clean up the caches for all replicas
> as the info from primary meta replica is up-to-date.
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