[Pacemaker] Signal hangup handling for pacemaker and corosync

Wed Jul 23 00:06:17 EDT 2014

Hi Andrew

Yes this change would be useful.

Regards
Arjun

On Wed, Jul 23, 2014 at 8:26 AM, Andrew Beekhof <andrew at beekhof.net> wrote:
>
> On 21 Jul 2014, at 3:45 pm, Vladislav Bogdanov <bubble at hoster-ok.com> wrote:
>
>> 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.
>
> How about: https://github.com/beekhof/pacemaker/commit/95175f5
>
>>
>>>
>>>> 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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>>>>>>>>>>>
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>>>>>>>>>>>
>>>>>>>>>>
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>>>>>>>>>>
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>>>>>>>>>
>>>>>>>>>
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>>>>>>>>>
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>>>>>>>>> Bugs: http://bugs.clusterlabs.org
>>>>>>>>>
>>>>>>>>
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>>>>>>>>
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>>>>>>>> Bugs: http://bugs.clusterlabs.org
>>>>>>>
>>>>>>>
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>>>>>>>
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>>>>>>> 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
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
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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
>>>>>
>>>>
>>>>
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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
>>>
>>>
>>>
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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
>
>
> _______________________________________________
> 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
>