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Date: Sat, 27 Aug 2011 11:01:19 -0400
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 <CAHwLALMj6MsyO_nxVAQWP6MT1Luos5Fpbk3qt=VFe4LFHy_HXg@mail.gmail.com>
Subject: Re: Getting traffic_server to dump core
From: Rayson Ho <raysonlogin@gmail.com>
To: dev@trafficserver.apache.org
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There's also the setuid(2)/seteuid(2)/setguid(2)/seteguid(2) issue on
Linux (the kernel does not dump core setXid programs).

There are a few places that trafficserver calls those system calls
(eg. in runAsUser()).

There are 2 ways of working around this:

1) In Sun Grid Engine (now the commercial Oracle Grid Engine and the
Open-Source Grid Engine project called Open Grid Scheduler) we use an
LD_PRELOAD wrapper to reset the core-dump bit after those system calls
are called.

You might want to take a look at our wrapper:

http://gridscheduler.sourceforge.net/patches/libcore.c

% gcc -D_GNU_SOURCE -fPIC -c libcore.c
% gcc -shared -o libcore.so libcore.o -lpthread

Then LD_PRELOAD libcore.so into the application to enable core dump.


2) There is also a easier (but a bit less secure way), and enabling it
could cause sensitive data to be dumped to disk as it is a system-wide
setting:

# sysctl -w kernel.core_setuid_ok=1

Rayson


On Sat, Aug 27, 2011 at 10:24 AM, Leif Hedstrom <leif@ogre.com> wrote:
> On 08/26/2011 11:32 PM, Alan M. Carroll wrote:
>>
>> I want to have traffic_server leave behind a core file when it crashes but
>> can't seem to make it happen. I have
>>
>> * Used ulimit -c
>> * Set the core limit high in /etc/security/limits.conf
>> * Set proxy.config.core_limit to -1
>> * Verified that setrlimit is being called with a very large limit.
>> * Set the permissions to 777 on INSTALL and INSTALL/bin.
>>
>
>
> Did you specify where it's should core dump? There's a sysctl for that.
>
> -- Leif
>
>


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