[HDFS-14271] [SBN read] StandbyException is logged if Observer is the first NameNode

• Type: Improvement
• Status: Patch Available
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 3.3.0
• Component/s: hdfs
• Labels: multi-sbnn
• Assignee: Shen Yinjie
• Reporter: Wei-Chiu Chuang
• Created: 13/Feb/19 00:44
• Updated: 11/Mar/22 07:48

Description

If I transition the first NameNode into Observer state, and then I create a file from command line, it prints the following StandbyException log message, as if the command failed. But it actually completed successfully:

[root@weichiu-sbsr-1 ~]# hdfs dfs -touchz /tmp/abf
19/02/12 16:35:17 INFO retry.RetryInvocationHandler: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.ipc.StandbyException): Operation category WRITE is not supported in state observer. Visit https://s.apache.org/sbnn-error
	at org.apache.hadoop.hdfs.server.namenode.ha.StandbyState.checkOperation(StandbyState.java:98)
	at org.apache.hadoop.hdfs.server.namenode.NameNode$NameNodeHAContext.checkOperation(NameNode.java:1987)
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkOperation(FSNamesystem.java:1424)
	at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.create(NameNodeRpcServer.java:762)
	at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.create(ClientNamenodeProtocolServerSideTranslatorPB.java:458)
	at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
	at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:530)
	at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1070)
	at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:918)
	at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:853)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:422)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1729)
	at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2782)
, while invoking $Proxy4.create over [weichiu-sbsr-1.gce.cloudera.com/172.31.121.145:8020,weichiu-sbsr-2.gce.cloudera.com/172.31.121.140:8020]. Trying to failover immediately.

This is unlike the case when the first NameNode is the Standby, where this StandbyException is suppressed.

Issue Links

• is related to: HDFS-12943 Consistent Reads from Standby Node
• relates to: HDFS-14855 client always print standbyexception info with multi standby namenode