Kill tasks on a node if the free physical memory on that machine falls below a 
configured threshold
---------------------------------------------------------------------------------------------------

                 Key: MAPREDUCE-1221
                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-1221
             Project: Hadoop Map/Reduce
          Issue Type: Improvement
          Components: tasktracker
            Reporter: dhruba borthakur
            Assignee: dhruba borthakur


The TaskTracker currently supports killing tasks if the virtual memory of a 
task exceeds a set of configured thresholds. I would like to extend this 
feature to enable killing tasks if the physical memory used by that task 
exceeds a certain threshold.

On a certain operating system (guess?), if user space processes start using 
lots of memory, the machine hangs and dies quickly. This means that we would 
like to prevent map-reduce jobs from triggering this condition. From my 
understanding, the killing-based-on-virtual-memory-limits (HADOOP-5883) were 
designed to address this problem. This works well when most map-reduce jobs are 
Java jobs and have well-defined -Xmx parameters that specify the max virtual 
memory for each task. On the other hand, if each task forks off 
mappers/reducers written in other languages (python/php, etc), the total 
virtual memory usage of the process-subtree varies greatly. In these cases, it 
is better to use kill-tasks-using-physical-memory-limits.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to