[APEXCORE-45] Certain HDFS calls from Apex give NPE with Hadoop 2.7.x

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Assignee: David Yan
• Reporter: David Yan
• Created: 11/Aug/15 21:39
• Updated: 17/Apr/17 23:36
• Resolved: 03/Mar/16 20:56

Description

How to reproduce:

• install apache hadoop 2.7.x
• install RTS 3.0.0 community edition as root
• On the hadoop installation screen in the install wizard, for the DFS root directory field, enter a directory that does not exist, whose parent dtadmin does not have write access to. For example: /user/root/datatorrent.

Exception is thrown on the namenode:

java.lang.NullPointerException
        at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkOwner(FSPermissionChecker.java:247)
        at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:227)
        at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:190)
        at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:1698)
        at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:1682)
        at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkOwner(FSDirectory.java:1651)
        at org.apache.hadoop.hdfs.server.namenode.FSDirAttrOp.setPermission(FSDirAttrOp.java:61)
        at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.setPermission(FSNamesystem.java:1653)
        at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.setPermission(NameNodeRpcServer.java:693)
        at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.setPermission(ClientNamenodeProtocolServerSideTranslatorPB.java:453)
        at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
        at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)
        at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:969)
        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049)
        at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:415)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
        at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2043)

[e-mail] on the apex-dev mailing list also mentioned there is another exception in STRAM when FSStorageAgent tries to create a file in HDFS:

ERROR com.datatorrent.stram.StreamingAppMaster: Exiting Application Master
java.lang.NullPointerException
        at org.apache.hadoop.fs.AbstractFileSystem.create(AbstractFileSystem.java:551)
        at org.apache.hadoop.fs.FileContext$3.next(FileContext.java:686)
        at org.apache.hadoop.fs.FileContext$3.next(FileContext.java:682)
        at org.apache.hadoop.fs.FSLinkResolver.resolve(FSLinkResolver.java:90)
        at org.apache.hadoop.fs.FileContext.create(FileContext.java:682)
        at com.datatorrent.common.util.FSStorageAgent.save(FSStorageAgent.java:92)
        at com.datatorrent.stram.plan.physical.PhysicalPlan.initCheckpoint(PhysicalPlan.java:944)
        at com.datatorrent.stram.plan.physical.PhysicalPlan.<init>(PhysicalPlan.java:363)
        at com.datatorrent.stram.StreamingContainerManager.<init>(StreamingContainerManager.java:330)
        at com.datatorrent.stram.StreamingContainerManager.getInstance(StreamingContainerManager.java:2828)
        at com.datatorrent.stram.StreamingAppMasterService.serviceInit(StreamingAppMasterService.java:516)
        at org.apache.hadoop.service.AbstractService.init(AbstractService.java:163)
        at com.datatorrent.stram.StreamingAppMaster.main(StreamingAppMaster.java:98)

I am not able to reproduce the second exception.

Here's the link to the google group email thread:
https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!topic/apex-dev/CxZN-QtR5BE

Issue Links

• relates to: HDFS-9851 Name node throws NPE when setPermission is called on a path that does not exist
• links to: https://malhar.atlassian.net/browse/APEX-45