[Pacemaker] Advisory ordering on clones not working?

Vladislav Bogdanov bubble at hoster-ok.com
Fri Feb 24 02:00:22 EST 2012


24.02.2012 02:26, Andrew Beekhof wrote:
> On Tue, Feb 21, 2012 at 3:12 PM, Vladislav Bogdanov
> <bubble at hoster-ok.com> wrote:
>> 21.02.2012 02:40, Andrew Beekhof wrote:
>>> On Mon, Feb 20, 2012 at 11:49 PM, Vladislav Bogdanov
>>> <bubble at hoster-ok.com> wrote:
>>>> 20.02.2012 14:36, Andrew Beekhof wrote:
>>>>> On Mon, Feb 20, 2012 at 10:26 PM, Adrian Fita <adrian.fita at gmail.com> wrote:
>>>>>> Thanks, I figured it out by now. But the real problem I'm facing is
>>>>>> explained in http://oss.clusterlabs.org/pipermail/pacemaker/2012-February/013124.html
>>>>>> . Please also take a look there. This advisory thing was me trying to
>>>>>> solve the problem described in that message.
>>>>>
>>>>> Ok, I see that thread.  I'll get to that one soon.
>>>>
>>>> I now look at the similar case (advisory ordering doesn't work).
>>>>
>>>> I hope I can add some pointers on what exactly happens.
>>>>
>>>> Imagine you have two advisory-ordered resources each also depend
>>>> (colocated and mandatory ordered) on some other resource (f.e.
>>>> filesystem on drbd device Master state).
>>>> I now play with lustre filesystem. It consists of several parts:
>>>> * MGS (one per cluster, cluster can consist of several lustre filesystems)
>>>> * MDT (one per filesystem)
>>>> * OST (many per filesystem)
>>>> It is very important for lustre to operate properly that MDT is started
>>>> after MGS and OSTs started after MDT.
>>>
>>> The you must not use advisory constraints for this sequence.
>>
>> Heh, but then I will be unable to move filesystem parts between drbd
>> replicas for failover... Advisory ordering allows me to move MGS or MDT
>> to another replica without restarting all the OSTs.
>>
>> Need to think again about making them migratable...
>>
>>>
>>>>
>>>> In my case I have MDT configured to start after MGS (advisory) and each
>>>> OST to start after MDT. Each of lustre parts is resided on a drbd device
>>>> (stacked one, so there is one more drbd device under it).
>>>>
>>>> What I see after transition from stop-all-resources="true" to "false" is
>>>> that some OSTs (which are located on nodes different from where MDT is)
>>>> are started before MDT. I see that advisory ordering is not honored when
>>>> dependencies of "then" resource are satisfied before ones of "first"
>>>> resource.
>>>
>>> So /both/ sides of the constraint are starting or stopping but the PE
>>> isn't enforcing the ordering?
>>
>> At one moment LogActions prints that they all are about to start.
>> Then deps for two "then" resources are satisfied and they are actually
>> started while "first" resource is not.
> 
> Ok, can you file a bug for that please?  I'll get David to have a look.

Done (cl#5039, http://bugs.clusterlabs.org/show_bug.cgi?id=5039 )





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