[Pacemaker] Colocation constraint to External Managed Resource

[Lars Ellenberg]

On Thu, Oct 10, 2013 at 06:20:54PM +0200, Robert H. wrote:
> Hello,
> 
> Am 10.10.2013 16:18, schrieb Andreas Kurz:
> 
> >You configured a monitor operation for this unmanaged resource?
> 
> Yes, and some parts work as expected, however some behaviour is
> strange.
> 
> Config (relevant part only):
> ----------------------------
> 
> primitive mysql-percona lsb:mysql \
>         op start enabled="false" interval="0" \
>         op stop enabled="false" interval="0" \
>         op monitor enabled="true" timeout="20s" interval="10s" \

You probably also want to monitor even if pacemaker thinks this is
supposed to be stopped.

	op monitor interval=11s timeout=20s role=Stopped


>         meta migration-threshold="2" failure-timeout="30s"
> is-managed="false"
> clone CLONE-percona mysql-percona \
>         meta clone-max="2" clone-node-max="1" is-managed="false"
> location clone-percona-placement CLONE-percona \
>         rule $id="clone-percona-placement-rule" -inf: #uname ne
> NODE1 and #uname ne NODE2
> colocation APP-dev2-private-percona-withip inf: IP CLONE-percona
> 
> 
> Test:
> ----
> 
> I start by both Percona XtraDB machines running:
> 
>  IP-dev2-privatevip1        (ocf::heartbeat:IPaddr2):       Started
> NODE2
>  Clone Set: CLONE-percona [mysql-percona] (unmanaged)
>      mysql-percona:0    (lsb:mysql):    Started NODE1 (unmanaged)
>      mysql-percona:1    (lsb:mysql):    Started NODE2 (unmanaged)
> 
> shell# /etc/init.d/mysql stop on NODE2
> 
> ... Pacemaker reacts as expected ....
> 
>  IP-dev2-privatevip1        (ocf::heartbeat:IPaddr2):       Started
> NODE1
>  Clone Set: CLONE-percona [mysql-percona] (unmanaged)
>      mysql-percona:0    (lsb:mysql):    Started NODE1 (unmanaged)
>      mysql-percona:1    (lsb:mysql):    Started NODE2 (unmanaged)
> FAILED
> 
> 	 .. then I wait ....
> 	 .. after some time (1 min), the ressource is shown as running ...
> 
>  IP-dev2-privatevip1        (ocf::heartbeat:IPaddr2):       Started
> NODE1
>  Clone Set: CLONE-percona [mysql-percona] (unmanaged)
>      mysql-percona:0    (lsb:mysql):    Started NODE1 (unmanaged)
>      mysql-percona:1    (lsb:mysql):    Started NODE2 (unmanaged)
> 
> But it is definitly not running:
> 
> shell# /etc/init.d/mysql status
> MySQL (Percona XtraDB Cluster) is not running
> [FEHLGESCHLAGEN]
> 
> When I run probe "crm resource reprobe" it switches to:
> 
>  IP-dev2-privatevip1        (ocf::heartbeat:IPaddr2):       Started
> NODE1
>  Clone Set: CLONE-percona [mysql-percona] (unmanaged)
>      mysql-percona:0    (lsb:mysql):    Started NODE1 (unmanaged)
>      Stopped: [ mysql-percona:1 ]
> 
> Then when I start it again:
> 
> /etc/init.d/mysql start on NODE2
> 
> It stays this way:
> 
>  IP-dev2-privatevip1        (ocf::heartbeat:IPaddr2):       Started
> NODE1
>  Clone Set: CLONE-percona [mysql-percona] (unmanaged)
>      mysql-percona:0    (lsb:mysql):    Started NODE1 (unmanaged)
>      Stopped: [ mysql-percona:1 ]
> 
> Only a manual "reprobe" helps:
> 
>  IP-dev2-privatevip1        (ocf::heartbeat:IPaddr2):       Started
> NODE1
>  Clone Set: CLONE-percona [mysql-percona] (unmanaged)
>      mysql-percona:0    (lsb:mysql):    Started NODE1 (unmanaged)
>      mysql-percona:1    (lsb:mysql):    Started NODE2 (unmanaged)
> 
> Same thing happens when I reboot NODE2 (or other way around).
> 
> ---
> 
> I would expect that crm_mon ALWAYS reflects the local state, however
> it looks like a bug for me.

crm_mon reflects what is in the cib.  If no-one re-populates the cib
with the current state of the world, what it shows will be stale.

-- 
: Lars Ellenberg
: LINBIT | Your Way to High Availability
: DRBD/HA support and consulting http://www.linbit.com

DRBD® and LINBIT® are registered trademarks of LINBIT, Austria.