[JIRA] [remoting] (JENKINS-34322) Graceful error reporting if build agent runs unsupported version of Java

[k...@kohsuke.org (JIRA)]

Title: Message Title

Kohsuke Kawaguchi created an issue   Jenkins / JENKINS-34322 Graceful error reporting if build agent runs unsupported version of Java Issue Type: Bug Assignee: Unassigned Components: remoting Created: 2016/Apr/19 5:17 AM Priority: Major Reporter: Kohsuke Kawaguchi When build agent is started on Java6 or earlier, the user gets the following cryptic error: hudson.util.IOException2: Slave JVM has not reported exit code. Is it still running? at hudson.plugins.sshslaves.SSHLauncher.startSlave(SSHLauncher.java:953) at hudson.plugins.sshslaves.SSHLauncher.access$400(SSHLauncher.java:133) at hudson.plugins.sshslaves.SSHLauncher$2.call(SSHLauncher.java:711) at hudson.plugins.sshslaves.SSHLauncher$2.call(SSHLauncher.java:696) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) Caused by: java.io.IOException: Remote call on trusted-agent-1 failed at hudson.remoting.Channel.call(Channel.java:789) at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:508) at hudson.slaves.SlaveComputer.setChannel(SlaveComputer.java:381) at hudson.plugins.sshslaves.SSHLauncher.startSlave(SSHLauncher.java:945) ... 7 more Caused by: java.lang.ClassFormatError: Failed to load hudson.slaves.SlaveComputer$SlaveVersion at hudson.remoting.RemoteClassLoader.loadClassFile(RemoteClassLoader.java:340) at hudson.remoting.RemoteClassLoader.findClass(RemoteClassLoader.java:251) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:249) at hudson.remoting.MultiClassLoaderSerializer$Input.resolveClass(MultiClassLoaderSerializer.java:114) at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1589) at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1494) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1748) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1327) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:349) at hudson.remoting.UserRequest.deserialize(UserRequest.java:184) at hudson.remoting.UserRequest.perform(UserRequest.java:98) at hudson.remoting.UserRequest.perform(UserRequest.java:48) at hudson.remoting.Request$2.run(Request.java:326) at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:68) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:138) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918) at java.lang.Thread.run(Thread.java:662) at ......remote call to trusted-agent-1(Native Method) at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1416) at hudson.remoting.UserResponse.retrieve(UserRequest.java:220) at hudson.remoting.Channel.call(Channel.java:781) ... 10 more Caused by: java.lang.UnsupportedClassVersionError: hudson/slaves/SlaveComputer$SlaveVersion : Unsupported major.minor version 51.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) at java.lang.ClassLoader.defineClass(ClassLoader.java:615) at java.lang.ClassLoader.defineClass(ClassLoader.java:465) at hudson.remoting.RemoteClassLoader.loadClassFile(RemoteClassLoader.java:338) at hudson.remoting.RemoteClassLoader.findClass(RemoteClassLoader.java:251) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:249) at hudson.remoting.MultiClassLoaderSerializer$Input.resolveClass(MultiClassLoaderSerializer.java:114) at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1589) at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1494) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1748) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1327) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:349) at hudson.remoting.UserRequest.deserialize(UserRequest.java:184) at hudson.remoting.UserRequest.perform(UserRequest.java:98) at hudson.remoting.UserRequest.perform(UserRequest.java:48) at hudson.remoting.Request$2.run(Request.java:326) at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:68) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:138) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918) at java.lang.Thread.run(Thread.java:662) [04/19/16 05:12:30] Launch failed - cleaning up connection [04/19/16 05:12:30] [SSH] Connection closed. ERROR: Connection terminated java.io.IOException: Unexpected termination of the channel at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:50) Caused by: java.io.EOFException at java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2332) at java.io.ObjectInputStream$BlockDataInputStream.readShort(ObjectInputStream.java:2801) at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:801) at java.io.ObjectInputStream.<init>(ObjectInputStream.java:299) at hudson.remoting.ObjectInputStreamEx.<init>(ObjectInputStreamEx.java:48) at hudson.remoting.AbstractSynchronousByteArrayCommandTransport.read(AbstractSynchronousByteArrayCommandTransport.java:34) at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:48) We need better error diagnostics for this case. Unless you know Java you don't understand what this error means, and it's also not very obvious if the problem is coming from the remote side or the master side. Add Comment   This message was sent by Atlassian JIRA (v6.4.2#64017-sha1:e244265) -- You received this message because you are subscribed to the Google Groups "Jenkins Issues" group. To unsubscribe from this group and stop receiving emails from it, send an email to jenkinsci-issues+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.