Details
Major Description
Every several rounds of TestMasterReplication#testHFileCyclicReplication, we could observe below NPE in UT log:
java.lang.NullPointerException
at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:2257)
at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:118)
at org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:189)
at org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:169)
And related codes at RpcServer line 2257 are:
if (e instanceof ServiceException) { e = e.getCause(); } // increment the number of requests that were exceptions. metrics.exception(e); if (e instanceof LinkageError) throw new DoNotRetryIOException(e); if (e instanceof IOException) throw (IOException)e;
And after some debugging, we could find several places that constructing ServiceException with no cause, such as in RsRpcServices#replicateWALEntry:
if (regionServer.replicationSinkHandler != null) { ... } else { throw new ServiceException("Replication services are not initialized yet"); }
So we should firstly check and only reset e=e.getCause() when the cause is not null