[Pacemaker] Signal hangup handling for pacemaker and corosync

[Vladislav Bogdanov]

21.07.2014 06:28, Andrew Beekhof wrote:
> 
> On 15 Jul 2014, at 8:45 pm, Arjun Pandey <apandepublic at gmail.com> wrote:
> 
>> On Tue, Jul 15, 2014 at 3:36 PM, Andrew Beekhof <andrew at beekhof.net> wrote:
>>>
>>> On 15 Jul 2014, at 8:00 pm, Arjun Pandey <apandepublic at gmail.com> wrote:
>>>
>>>> Right. Actually the issue i am facing is that i am starting the
>>>> pacemaker service remotely from a wrapper and thus pacemakerd dies
>>>> when the wrapper exits.nohup solves the problem but then HUP cannot be
>>>> used by pacemaker. Is this workaround ok ?
>>>
>>> I guess. How are you starting pacemaker?  Usually its with some variant of 'service pacemaker start'.
>> I am using 'service pacemaker start'. However this is being called
>> from my script. So when the script exits pacemaker gets SIGHUP.
> 
> Release testing starts clusters as:
> 
>    ssh -l root somenode -- service pacemaker start

It could depend on what "service" is.
It would either schedule systemd to run job (el7/fc18+), or just run
init script itself (el6). In latter case, if process didn't detach from
its controlling terminal when that terminal gone away, it will be sent a
SIGHUP. I'd recommend adding HUP handler (f.e. ignore) or/and detach
(setsid()) right before daemonizing.

> 
> And I've never seen the behaviour you speak of.
> How is what you're doing different?
> 
>>>
>>>>
>>>> I was checking out the current pacemaker code.setsid is called for
>>>> each child process.However if we do this for main process to then it
>>>> will also be detached from the terminal.
>>>>
>>>> Regards
>>>> Arjun
>>>>
>>>>
>>>>
>>>> On Tue, Jul 15, 2014 at 3:01 PM, Andrew Beekhof <andrew at beekhof.net> wrote:
>>>>>
>>>>> On 15 Jul 2014, at 7:13 pm, Arjun Pandey <apandepublic at gmail.com> wrote:
>>>>>
>>>>>> Hi Andrew
>>>>>>
>>>>>> AFAIK linux daemons don't terminate on SIGHUP.
>>>>>
>>>>> Read the man page, POSIX specifies that the default action is 'term' ie. 'terminate'.
>>>>>
>>>>>> They typically reload
>>>>>> configuration on receiving this signal.Eg- rsyslogd. I thought it was
>>>>>> safe to make this assumption here as well.
>>>>>
>>>>> Not anywhere as it turns out
>>>>>
>>>>>>
>>>>>> Regards
>>>>>> Arjun
>>>>>>
>>>>>> On Tue, Jul 15, 2014 at 2:15 PM, Andrew Beekhof <andrew at beekhof.net> wrote:
>>>>>>>
>>>>>>> On 15 Jul 2014, at 6:19 pm, Arjun Pandey <apandepublic at gmail.com> wrote:
>>>>>>>
>>>>>>>> Hi all
>>>>>>>>
>>>>>>>> I am running pacemaker version 1.1.10-14.el6 on CentOS 6. On setting
>>>>>>>> up cluster if I send SIGHUP to either pacemaker or corosync services ,
>>>>>>>> they die.
>>>>>>>> Is this a bug ? What is the intension behind this behavior?
>>>>>>>
>>>>>>> Standard default I believe.
>>>>>>> Have you run 'man 7 signal' lately?
>>>>>>>
>>>>>>> _______________________________________________
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>>>>>>>
>>>>>>> Project Home: http://www.clusterlabs.org
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>>>>>>>
>>>>>>
>>>>>> _______________________________________________
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>>>>>>
>>>>>> Project Home: http://www.clusterlabs.org
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>>>>>> Bugs: http://bugs.clusterlabs.org
>>>>>
>>>>>
>>>>> _______________________________________________
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>>>>> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
>>>>>
>>>>> Project Home: http://www.clusterlabs.org
>>>>> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
>>>>> Bugs: http://bugs.clusterlabs.org
>>>>>
>>>>
>>>> _______________________________________________
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>>>> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
>>>>
>>>> Project Home: http://www.clusterlabs.org
>>>> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
>>>> Bugs: http://bugs.clusterlabs.org
>>>
>>>
>>> _______________________________________________
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>>>
>>> Project Home: http://www.clusterlabs.org
>>> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
>>> Bugs: http://bugs.clusterlabs.org
>>>
>>
>> _______________________________________________
>> Pacemaker mailing list: Pacemaker at oss.clusterlabs.org
>> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
>>
>> Project Home: http://www.clusterlabs.org
>> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
>> Bugs: http://bugs.clusterlabs.org
> 
> 
> 
> _______________________________________________
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> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
> 
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org
>