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https://issues.apache.org/jira/browse/HADOOP-3280?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12591211#action_12591211
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Amareshwari Sriramadasu commented on HADOOP-3280:
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Sigh! I missed that mapred.task.prologue can be a script, used to set
resource limits, environment variables etc. that affect the task.
Then, it looks like option (2) for the default behavior is ruled out, because
we dont know whether setting the ulimit is already part of prologue or not. And
if it is not, we assume that user does not want to set ulimit.
So, the default behavior will be _no ulimit setting_ for the streaming/pipes
tasks.
Thoughts?
> virtual address space limits break streaming apps
> -------------------------------------------------
>
> Key: HADOOP-3280
> URL: https://issues.apache.org/jira/browse/HADOOP-3280
> Project: Hadoop Core
> Issue Type: Bug
> Components: contrib/streaming
> Reporter: Rick Cox
> Assignee: Amareshwari Sriramadasu
> Priority: Blocker
> Fix For: 0.17.0
>
> Attachments: HADOOP-3280_0_20080418.patch
>
>
> HADOOP-2765 added a mandatory, hard virtual address space limit to streaming
> apps based on the Java process's -Xmx setting.
> This makes it impossible to run a 64-bit streaming app that needs large
> address spaces under a 32-bit JVM, even if one is otherwise willing to
> dramatically increase the -Xmx setting without cause. Also, unlike Java's
> -Xmx limit, the virtual address space limit for an arbitrary UNIX process
> does not necessarily correspond to RAM usage, so it's likely to be a
> relatively difficult to configure limit.
> 2765 was originally opened to allow an optional wrapper script around
> streaming tasks, one use case for which was setting a ulimit. That approach
> seems much less intrusive and more flexible than the final implementation.
> The ulimit can also be trivially set by the streaming task itself without any
> support from Hadoop.
> Marking this as an 0.17 blocker because it will break deployed apps and there
> is no workaround available.
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