The problem is probably not related to the JVM memory so much as the Linux memory manager. The exception is in java.lang.UNIXProcess.<init>(UNIXProcess.java:148) which would imply this is happening when trying to create a new process. The initial malloc for the new process space is being denied by the memory manager. There could be many reasons why this happens, though the most likely is your overcommit settings and swap space. I'd suggest reading through these details:
https://www.kernel.org/doc/Documentation/vm/overcommit-accounting On Sat, Apr 20, 2013 at 4:00 PM, Kishore Yellamraju < [email protected]> wrote: > All, > > I have posted this question to CDH ML , but i guess i can post it here > because its a general hadoop question. > > When the NN or JT gets the rack info, i guess it stores the info in > memory. can i ask you where in the JVM memory it will store the results ( > perm gen ?) ? . I am getting "cannot allocate memory on NN and JT " and > they have more than enough memory. when i looked at JVM usage stats i can > see it doesnt have enough perm free space.so if its storing the values in > perm gen then there is a chance of this memory issues. > > > Thanks in advance !!! > > > exception that i see in logs : > > java.io.IOException: Cannot run program "/etc/hadoop/conf/topo.sh" (in > directory "/usr/lib/hadoop-0.20-mapreduce"): java.io.IOException: error=12, > Cannot allocate memory > at java.lang.ProcessBuilder.start(ProcessBuilder.java:459) > at org.apache.hadoop.util.Shell.runCommand(Shell.java:206) > at org.apache.hadoop.util.Shell.run(Shell.java:188) > at > org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:381) > at > org.apache.hadoop.net.ScriptBasedMapping$RawScriptBasedMapping.runResolveCommand(ScriptBasedMapping.java:242) > at > org.apache.hadoop.net.ScriptBasedMapping$RawScriptBasedMapping.resolve(ScriptBasedMapping.java:180) > at > org.apache.hadoop.net.CachedDNSToSwitchMapping.resolve(CachedDNSToSwitchMapping.java:119) > at > org.apache.hadoop.mapred.JobTracker.resolveAndAddToTopology(JobTracker.java:2750) > at > org.apache.hadoop.mapred.JobInProgress.createCache(JobInProgress.java:593) > at > org.apache.hadoop.mapred.JobInProgress.initTasks(JobInProgress.java:765) > at > org.apache.hadoop.mapred.JobTracker.initJob(JobTracker.java:3775) > at > org.apache.hadoop.mapred.EagerTaskInitializationListener$InitJob.run(EagerTaskInitializationListener.java:90) > at > java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) > at java.lang.Thread.run(Thread.java:619) > Caused by: java.io.IOException: java.io.IOException: error=12, Cannot > allocate memory > at java.lang.UNIXProcess.<init>(UNIXProcess.java:148) > at java.lang.ProcessImpl.start(ProcessImpl.java:65) > at java.lang.ProcessBuilder.start(ProcessBuilder.java:452) > ... 14 more > 2013-04-20 02:07:28,298 ERROR org.apache.hadoop.mapred.JobTracker: Job > initialization failed: > java.lang.NullPointerException > > > -Thanks > kishore kumar yellamraju |Ground control operations| > [email protected] | 408.203.0424 > >
