Details
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Bug
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Status: Resolved
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Major
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Resolution: Fixed
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2.5.0, 2.6.0, 2.7.0, 2.8.0, 3.0.0-alpha1
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None
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None
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Reviewed
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Only check permissions when permissions enabled in FSDirStatAndListingOp.getFileInfo() and getListingInt()
Description
FSNamesystem (2.5.x)/FSDirStatAndListingOp(current trunk) getFileInfo and getListingInt methods call getPermissionChecker() to construct a FSPermissionChecker regardless of isPermissionEnabled(). When permission checking is disabled, this leads to an unnecessary performance hit constructing a UserGroupInformation object that is never used.
For example, from a stack dump when driving concurrent requests, they all end up blocking.
Here's the thread holding the lock:
"IPC Server handler 9 on 9000" daemon prio=10 tid=0x00007f78d8b9e800 nid=0x142f3 runnable [0x00007f78c2ddc000]
java.lang.Thread.State: RUNNABLE
at java.io.FileInputStream.readBytes(Native Method)
at java.io.FileInputStream.read(FileInputStream.java:272)
at java.io.BufferedInputStream.read1(BufferedInputStream.java:273)
at java.io.BufferedInputStream.read(BufferedInputStream.java:334)
- locked <0x00000007d9b105c0> (a java.lang.UNIXProcess$ProcessPipeInputStream)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:283)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:325)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:177) - locked <0x00000007d9b1a888> (a java.io.InputStreamReader)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:154)
at java.io.BufferedReader.read1(BufferedReader.java:205)
at java.io.BufferedReader.read(BufferedReader.java:279) - locked <0x00000007d9b1a888> (a java.io.InputStreamReader)
at org.apache.hadoop.util.Shell$ShellCommandExecutor.parseExecResult(Shell.java:715)
at org.apache.hadoop.util.Shell.runCommand(Shell.java:524)
at org.apache.hadoop.util.Shell.run(Shell.java:455)
at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:702)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:791)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:774)
at org.apache.hadoop.security.ShellBasedUnixGroupsMapping.getUnixGroups(ShellBasedUnixGroupsMapping.java:84)
at org.apache.hadoop.security.ShellBasedUnixGroupsMapping.getGroups(ShellBasedUnixGroupsMapping.java:52)
at org.apache.hadoop.security.JniBasedUnixGroupsMappingWithFallback.getGroups(JniBasedUnixGroupsMappingWithFallback.java:50)
at org.apache.hadoop.security.Groups.getGroups(Groups.java:139)
at org.apache.hadoop.security.UserGroupInformation.getGroupNames(UserGroupInformation.java:1474) - locked <0x00000007a6df75f8> (a org.apache.hadoop.security.UserGroupInformation)
at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.<init>(FSPermissionChecker.java:82)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getPermissionChecker(FSNamesystem.java:3534)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getListingInt(FSNamesystem.java:4489)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getListing(FSNamesystem.java:4478)
at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.getListing(NameNodeRpcServer.java:898)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.getListing(ClientNamenodeProtocolServerSideTranslatorPB.java:602)
at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:585)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:928)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2013)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2009)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1614)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2007)
Here is (one of the many) threads waiting on the lock:
"IPC Server handler 2 on 9000" daemon prio=10 tid=0x00007f78d8c48800 nid=0x142ec waiting for monitor entry [0x00007f78c34e3000]
java.lang.Thread.State: BLOCKED (on object monitor)
at org.apache.hadoop.security.UserGroupInformation.getGroupNames(UserGroupInformation.java:1472)
- waiting to lock <0x00000007a6df75f8> (a org.apache.hadoop.security.UserGroupInformation)
at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.<init>(FSPermissionChecker.java:82)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getPermissionChecker(FSNamesystem.java:3534)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getListingInt(FSNamesystem.java:4489)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getListing(FSNamesystem.java:4478)
at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.getListing(NameNodeRpcServer.java:898)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.getListing(ClientNamenodeProtocolServerSideTranslatorPB.java:602)
at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:585)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:928)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2013)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2009)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1614)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2007)