[Pacemaker] Advisory ordering on clones not working?

Andrew Beekhof andrew at beekhof.net
Mon Feb 20 23:40:02 UTC 2012


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.

>
> 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?


> hb_report?
>
> Best,
> Vladislav
>
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