Stopping ceph daemons during the upgrade

Stopping ceph daemons during the upgrade

[Loic Dachary]

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Hi,

To not confuse the ceph daemons during a package upgrade ( see http://tracker.ceph.com/issues/9153#note-13 for instance ), it would be better to stop the ceph daemons while ceph is being upgraded. Does that sound reasonable ?

Here is how it could be done for .deb packages : https://github.com/dachary/ceph/commit/cf3a0e7bef25e5190f3cdb69e57cb6b868d806fa and there probably is a way to do something similar with RPM packages. 

Cheers

-- 
Loïc Dachary, Artisan Logiciel Libre


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Re: Stopping ceph daemons during the upgrade

[Dan Van Der Ster]

Hi,

On 18 Aug 2014, at 17:19, Loic Dachary <loic@dachary.org> wrote:

> there probably is a way to do something similar with RPM packages. 

That behaviour (well, close enough) just _removed_ from firefly, see:
  https://github.com/ceph/ceph/commit/361c1f8554ce1fedfd0020cd306c41b0ba25f53e

I don’t have a strong opinion if the pkg update should restart the daemon or not — but we should try not to change this too often as it changes our operating procedures.

Cheers, Dan--
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Re: Stopping ceph daemons during the upgrade

[Loic Dachary]

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Hi Dan,

Pre-loading the erasure code plugins will reduce this race condition (i.e. the files will have to be modified between the start of the ceph-osd process and the bootstrap phase where it loads the plugins for it to happen) and it seems to be preferable to stopping the daemons. Thanks for giving an additional incentive to go in this direction !

Cheers

On 18/08/2014 17:31, Dan Van Der Ster wrote:
> Hi,
> 
> On 18 Aug 2014, at 17:19, Loic Dachary <loic@dachary.org> wrote:
> 
>> there probably is a way to do something similar with RPM packages. 
> 
> That behaviour (well, close enough) just _removed_ from firefly, see:
>   https://github.com/ceph/ceph/commit/361c1f8554ce1fedfd0020cd306c41b0ba25f53e
> 
> I don’t have a strong opinion if the pkg update should restart the daemon or not — but we should try not to change this too often as it changes our operating procedures.
> 
> Cheers, Dan--
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

-- 
Loïc Dachary, Artisan Logiciel Libre


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Re: Stopping ceph daemons during the upgrade

[Sage Weil]

On Mon, 18 Aug 2014, Loic Dachary wrote:
> Hi Dan,
> 
> Pre-loading the erasure code plugins will reduce this race condition 
> (i.e. the files will have to be modified between the start of the 
> ceph-osd process and the bootstrap phase where it loads the plugins for 
> it to happen) and it seems to be preferable to stopping the daemons. 
> Thanks for giving an additional incentive to go in this direction !

BTW Loic, one other thing would could do is have a number or string in the 
.so interface that we bump when the interface changes.  Then loading the 
plugin could fail with a friendly message instead of crashing.

sage

Re: Stopping ceph daemons during the upgrade

[Loic Dachary]

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Good idea :-)

On 18/08/2014 18:08, Sage Weil wrote:
> On Mon, 18 Aug 2014, Loic Dachary wrote:
>> Hi Dan,
>>
>> Pre-loading the erasure code plugins will reduce this race condition 
>> (i.e. the files will have to be modified between the start of the 
>> ceph-osd process and the bootstrap phase where it loads the plugins for 
>> it to happen) and it seems to be preferable to stopping the daemons. 
>> Thanks for giving an additional incentive to go in this direction !
> 
> BTW Loic, one other thing would could do is have a number or string in the 
> .so interface that we bump when the interface changes.  Then loading the 
> plugin could fail with a friendly message instead of crashing.
> 
> sage
> --
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> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

-- 
Loïc Dachary, Artisan Logiciel Libre


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