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Re: [PATCH] (updated) fix for ssh zombies introduced with r35533

From: Hyrum K. Wright <hyrum_at_hyrumwright.org>
Date: Fri, 1 May 2009 07:41:11 -0500

I'm currently testing (or rather, waiting for feedback from a couple
of people who are testing) this patch in a large deployment with ssh
connection sharing. I plan to continue tracking this, but in case I
get hit by a bus, I believe the patch is attached to the issue, so it
won't get lost.

-Hyrum

On May 1, 2009, at 5:55 AM, Gavin Baumanis wrote:

> Ping. This patch proposal has received no comments and I haven't
> noticed it being committed, either.
>
> Gavin.
>
>
> On 22/04/2009, at 8:47 AM, Kyle McKay wrote:
>
>> [[[
>> Fix ssh zombie problem introduced with revision 35533
>>
>> * subversion/libsvn_ra_svn/client.c
>> (make_tunnel): Fully detach tunnel process to avoid having it
>> receive signals while restoring the original
>> apr_pool_note_subprocess to avoid creating zombies.
>> ]]]
>>
>> Updated so that WIN32 behavior remains the same after applying this
>> patch as it was after revision 35533. The earlier version of the
>> patch inadvertently reverted WIN32 behavior to the pre-r35533 state.
>>
>> Kyle
>>
>>> As detailed in this thread:
>>>
>>> http://subversion.tigris.org/ds/viewMessage.do?dsForumId=462&dsMessageId=1445592
>>>
>>> regarding the change introduced into client.c by revision 35533:
>>>
>>> http://svn.collab.net/viewvc/svn?view=revision&revision=35533
>>>
>>> On Mar 27, 2009, at 09:51, Hyrum K. Wright wrote:
>>>> The case which drove r35533 was a user who uses ssh connection
>>>> pooling for svn connections.
>>>
>>> Change r35533 removed the call to to apr_pool_note_subprocess
>>> meaning that Subversion never reaps any of its children. This may
>>> be okay for a short-lived process, but is not okay for a long-lived
>>> process such as a GUI tool that has linked with the Subversion
>>> library.
>>>
>>> If the GUI tool runs long enough, it can create so many un-reaped
>>> zombie processes that system resources are exhausted and it becomes
>>> impossible to spawn any new processes.
>>>
>>> The attached patch restores the original call to
>>> apr_pool_note_subprocess thus guaranteeing no zombies are ever
>>> created. It also arranges for the tunnel process to become detached
>>> so that it can "die in piece, in its own time, on its own terms" as
>>> the log comment for revision 35533 mentions, but without causing
>>> zombie processes to be created.
>>>
>>> This change retains full compatibility with ssh connection pooling
>>> while eliminating the zombie problem. See issue #2580 for the
>>> original impetus for the change made in revision 35533.
>>>
>>> http://subversion.tigris.org/issues/show_bug.cgi?id=2580
>>>
>>> Kyle
>>
>> ------------------------------------------------------
>> http://subversion.tigris.org/ds/viewMessage.do?dsForumId=462&dsMessageId=1849826
>> <client.c-patch_v2>
>
> ------------------------------------------------------
> http://subversion.tigris.org/ds/viewMessage.do?dsForumId=462&dsMessageId=2012775

------------------------------------------------------
http://subversion.tigris.org/ds/viewMessage.do?dsForumId=462&dsMessageId=2014068
Received on 2009-05-01 14:41:31 CEST

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