[ACCUMULO-4341] ServiceLoader deadlock with classes loaded from HDFS

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.7.0, 1.8.0
• Fix Version/s: 1.7.2, 1.8.0
• Component/s: client
• Assignee: Dave Marion
• Reporter: Dave Marion
• Created: 13/Jun/16 15:37
• Updated: 14/Jun/16 13:26
• Resolved: 14/Jun/16 13:26

Description

With Accumulo set up to use general.vfs.classpaths to load classes from HDFS, running `accumulo help` will hang.

A jstack of the process shows the IPC Client thread at:

   java.lang.Thread.State: BLOCKED (on object monitor)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:348)
	at org.apache.hadoop.conf.Configuration.getClassByNameOrNull(Configuration.java:2051)
	at org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:91)
	at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:75)
	at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:133)
	at org.apache.hadoop.ipc.Client$Connection.receiveRpcResponse(Client.java:1086)
	at org.apache.hadoop.ipc.Client$Connection.run(Client.java:966)

and the main thread at:

   java.lang.Thread.State: WAITING (on object monitor)
	at java.lang.Object.wait(Native Method)
	at java.lang.Object.wait(Object.java:502)
	at org.apache.hadoop.ipc.Client.call(Client.java:1454)
	- locked <0x00000000f09a2898> (a org.apache.hadoop.ipc.Client$Call)
	at org.apache.hadoop.ipc.Client.call(Client.java:1399)
	at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:232)
	at com.sun.proxy.$Proxy9.getFileInfo(Unknown Source)
	at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:752)
	at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:187)
	at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
	at com.sun.proxy.$Proxy10.getFileInfo(Unknown Source)
	at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1982)
	at org.apache.hadoop.hdfs.DistributedFileSystem$18.doCall(DistributedFileSystem.java:1128)
	at org.apache.hadoop.hdfs.DistributedFileSystem$18.doCall(DistributedFileSystem.java:1124)
	at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
	at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1124)
	at org.apache.commons.vfs2.provider.hdfs.HdfsFileObject.doAttach(HdfsFileObject.java:85)
	at org.apache.commons.vfs2.provider.AbstractFileObject.attach(AbstractFileObject.java:173)
	- locked <0x00000000f57fd008> (a org.apache.commons.vfs2.provider.hdfs.HdfsFileSystem)
	at org.apache.commons.vfs2.provider.AbstractFileObject.getContent(AbstractFileObject.java:1236)
	- locked <0x00000000f57fd008> (a org.apache.commons.vfs2.provider.hdfs.HdfsFileSystem)
	at org.apache.commons.vfs2.impl.VFSClassLoader.getPermissions(VFSClassLoader.java:300)
	at java.security.SecureClassLoader.getProtectionDomain(SecureClassLoader.java:206)
	- locked <0x00000000f5ad9138> (a java.util.HashMap)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at org.apache.commons.vfs2.impl.VFSClassLoader.defineClass(VFSClassLoader.java:226)
	at org.apache.commons.vfs2.impl.VFSClassLoader.findClass(VFSClassLoader.java:180)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	- locked <0x00000000f5af3b88> (a org.apache.commons.vfs2.impl.VFSClassLoader)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:411)
	- locked <0x00000000f6f5c2f8> (a org.apache.commons.vfs2.impl.VFSClassLoader)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:348)
	at java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:370)
	at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:404)
	at java.util.ServiceLoader$1.next(ServiceLoader.java:480)
	at org.apache.accumulo.start.Main.checkDuplicates(Main.java:196)
	at org.apache.accumulo.start.Main.getExecutables(Main.java:188)
	at org.apache.accumulo.start.Main.main(Main.java:52)

Issue Links

• blocks: ACCUMULO-3923 bootstrap_hdfs.sh does not copy correct jars to hdfs
• links to: GitHub Pull Request #113