[HDFS-13743] RBF: Router throws NullPointerException due to the invalid initialization of MountTableResolver

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.1.0, 3.0.3
• Fix Version/s: 2.10.0, 3.2.0, 2.9.2, 3.0.4, 3.1.2
• Hadoop Flags: Reviewed
• Assignee: Takanobu Asanuma
• Reporter: Takanobu Asanuma
• Created: 18/Jul/18 13:10
• Updated: 20/Jul/18 10:22
• Resolved: 20/Jul/18 09:36

Description

When dfs.federation.router.default.nameserviceId isn't set and any other default name service isn't found, clients can't submit requests to the router because of NullPointerException.

1. client side

   $ hadoop fs -ls hdfs://router:8888/
   ls: java.lang.NullPointerException
   

1. Router log

   java.lang.NullPointerException
           at java.util.TreeMap.getEntry(TreeMap.java:347)
           at java.util.TreeMap.containsKey(TreeMap.java:232)
           at java.util.TreeSet.contains(TreeSet.java:234)
           at org.apache.hadoop.hdfs.server.federation.router.RouterRpcServer.getLocationsForPath(RouterRpcServer.java:2287)
           at org.apache.hadoop.hdfs.server.federation.router.RouterRpcServer.getLocationsForPath(RouterRpcServer.java:2239)
           at org.apache.hadoop.hdfs.server.federation.router.RouterRpcServer.getFileInfo(RouterRpcServer.java:1163)
           at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.getFileInfo(ClientNamenodeProtocolServerSideTranslatorPB.java:966)
           at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
           at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:524)
           at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1025)
           at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:876)
           at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:822)
           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:1689)
           at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2682)
   

The cause of this error is that the initialization of MountTableResolver doesn't work properly.