Throwing exception when meta region is not in OPEN state in client registry may crash a master

2019-05-26 17:10:31,195 ERROR [master/asf906:0:becomeActiveMaster] helpers.MarkerIgnoringBase(159): Failed to become active master
org.apache.hadoop.hbase.client.RetriesExhaustedException: Cannot get the location for replica0 of region for  in hbase:meta
	at org.apache.hadoop.hbase.client.RpcRetryingCallerWithReadReplicas.getRegionLocations(RpcRetryingCallerWithReadReplicas.java:335)
	at org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:153)
	at org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:58)
	at org.apache.hadoop.hbase.client.RpcRetryingCallerImpl.callWithoutRetries(RpcRetryingCallerImpl.java:192)
	at org.apache.hadoop.hbase.client.ClientScanner.call(ClientScanner.java:263)
	at org.apache.hadoop.hbase.client.ClientScanner.loadCache(ClientScanner.java:405)
	at org.apache.hadoop.hbase.client.ClientScanner.nextWithSyncCache(ClientScanner.java:285)
	at org.apache.hadoop.hbase.client.ClientScanner.next(ClientScanner.java:564)
	at org.apache.hadoop.hbase.MetaTableAccessor.scanMeta(MetaTableAccessor.java:766)
	at org.apache.hadoop.hbase.MetaTableAccessor.scanMeta(MetaTableAccessor.java:734)
	at org.apache.hadoop.hbase.MetaTableAccessor.scanMeta(MetaTableAccessor.java:690)
	at org.apache.hadoop.hbase.MetaTableAccessor.fullScanRegions(MetaTableAccessor.java:220)
	at org.apache.hadoop.hbase.master.assignment.RegionStateStore.visitMeta(RegionStateStore.java:77)
	at org.apache.hadoop.hbase.master.assignment.AssignmentManager.loadMeta(AssignmentManager.java:1294)
	at org.apache.hadoop.hbase.master.assignment.AssignmentManager.joinCluster(AssignmentManager.java:1255)
	at org.apache.hadoop.hbase.master.HMaster.finishActiveMasterInitialization(HMaster.java:1100)
	at org.apache.hadoop.hbase.master.HMaster.startActiveMasterManager(HMaster.java:2375)
	at org.apache.hadoop.hbase.master.HMaster.lambda$run$0(HMaster.java:605)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.io.IOException: Meta region is in state OPENING
	at org.apache.hadoop.hbase.client.ZKAsyncRegistry.lambda$getMetaRegionLocation$1(ZKAsyncRegistry.java:162)
	at org.apache.hadoop.hbase.util.FutureUtils.lambda$addListener$0(FutureUtils.java:70)
	at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760)
	at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:736)
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)
	at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1962)
	at org.apache.hadoop.hbase.client.ZKAsyncRegistry.lambda$getAndConvert$0(ZKAsyncRegistry.java:81)
	at org.apache.hadoop.hbase.util.FutureUtils.lambda$addListener$0(FutureUtils.java:70)
	at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760)
	at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:736)
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)
	at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1962)
	at org.apache.hadoop.hbase.zookeeper.ReadOnlyZKClient$ZKTask$1.exec(ReadOnlyZKClient.java:174)
	at org.apache.hadoop.hbase.zookeeper.ReadOnlyZKClient.run(ReadOnlyZKClient.java:342)
	... 1 more