[
https://issues.apache.org/jira/browse/HADOOP-4523?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12644220#action_12644220
]
Vivek Ratan commented on HADOOP-4523:
-------------------------------------
I'm proposing a couple of improvements:
# The TT currently monitors each task (and its descendants) to see if that
task's memory usage goes over a per-task limit. The TT should additionally
monitor to make sure that the sum of memory used by all tasks should not go
over a per-node limit (_tasks.maxmemory_). This situation is unlikely t happen
if schedulers consider memory judiciously when scheduling, but not all
schedulers may. In addition, the TT should pick tasks that ran last, when
deciding what tasks to kill.
# I'm also proposing a way to specify _tasks.maxmemory_. This particular
discussion is, however, going on in HADOOP-4035, so we can continue discussion
there.
> Enhance how memory-intensive user tasks are handled
> ---------------------------------------------------
>
> Key: HADOOP-4523
> URL: https://issues.apache.org/jira/browse/HADOOP-4523
> Project: Hadoop Core
> Issue Type: Improvement
> Components: mapred
> Affects Versions: 0.19.0
> Reporter: Vivek Ratan
> Assignee: Vinod K V
>
> HADOOP-3581 monitors each Hadoop task to see if its memory usage (which
> includes usage of any tasks spawned by it and so on) is within a per-task
> limit. If the task's memory usage goes over its limit, the task is killed.
> This, by itself, is not enough to prevent badly behaving jobs from bringing
> down nodes. What is also needed is the ability to make sure that the sum
> total of VM usage of all Hadoop tasks does not exceed a certain limit.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
