[Pacemaker] Signal hangup handling for pacemaker and corosync

Mon Jul 21 05:45:07 UTC 2014

21.07.2014 08:36, Andrew Beekhof wrote:
> 
> On 21 Jul 2014, at 2:50 pm, Vladislav Bogdanov <bubble at hoster-ok.com> wrote:
> 
>> 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.
> 
> Except we test rhel6 the same way...

I understand. This issue is from "sometimes happens on some systems"
folder. I recall I had problems ages ago with a daemon run from rc.local
sometimes exists with HUP. 'sleep 1' after its launch was the easiest fix.

> 
>> 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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>>>>>>>>> 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
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> 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
>>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> 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
>>>>>
>>>>
>>>> _______________________________________________
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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
>>>
>>
>>
>> _______________________________________________
>> 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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> 
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> 