[
https://issues.apache.org/jira/browse/MAPREDUCE-2341?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12997324#comment-12997324
]
Bhallamudi Venkata Siva Kamesh commented on MAPREDUCE-2341:
-----------------------------------------------------------
In the code segment(void org.apache.hadoop.mapred.Child.main(String[] args)
throws Throwable), this case has been handled as shown below
{code:title=Child.java|borderStyle=solid}
while(true) {
...................................................
numTasksToExecute = job.getNumTasksToExecutePerJvm();
assert(numTasksToExecute != 0);
...................................................
}
{code}
As assertions have not been enabled during runtime, the assertion statement
here failed to assert and loop goes infinete.
So I feel, we need to enable assertions while running HDFS/Mapreduce programs.
> Map and Reduce task JVMs are hanging infinitely
> ------------------------------------------------
>
> Key: MAPREDUCE-2341
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-2341
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: tasktracker
> Environment: Linux
> Reporter: Bhallamudi Venkata Siva Kamesh
>
> Description:
> When launching Mapreduce application, the property
> *mapred.job.reuse.jvm.num.tasks* has been set to *0*, as a result the task
> JVM(MAP or Reduce JVM) is hanging indefinitely and finally being killed by
> Tasktracker.
> Steps to Reproduce
> ------------------
> 1) Set the *mapred.job.reuse.jvm.num.tasks* property in mapred-site.xml to 0
> 2) Execute the wordcount example, child JVM is hanging indefinitely and
> finally killed by Tasktracker
--
This message is automatically generated by JIRA.
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
