[Pacemaker] Resource starts on wrong node ?

[Dan Frincu]

Hi,

On Wed, Sep 21, 2011 at 1:02 PM, Hans Lammerts <j.lammerts at chello.nl> wrote:
> Hi all,
>
>
>
> Just started to configure a two node cluster (Centos 6) with drbd
> 8.4.0-31.el6,
>
> corosync 1.2.3 and pacemaker 1.1.2.

Strange choice of versions, if it's a new setup, why don't you go for
corosync 1.4.1 and pacemaker 1.1.5?

>
> I created three DRBD filesystems, and started to add them in the crm config
> one by one.
>
> Everything went OK. After adding these resources they start on node1, and
> when I set node1
>
> in standby, these three DRBD resources failover nicely to the second node.
> And vice versa.
>
> So far so good.
>
>
>
> Next, I added one extra resource, that is supposed to put an IP alias on
> eth0.
>
> This also works, but strangely enough the alias is set on eth0 of the second
> node, where I would have
>
> expected it to start on the first node (just as the three drbd resources
> did).
>
> Why the.... does Pacemaker decide that this resource is to be started on the
> second node ? I cannot grasp
>
> the reason why.

Because it tries to load balance resources on available nodes. You
have several resources running on one node, and didn't specify any
restrictions on the mysqlip, therefore it chose the second node as it
had less resources on it. You override the behavior with constraints.
See below.

>
> Hope anyone can tell me what I'm doing wrong.
>
>
>
> Thanks,
>
> Hans
>
>
>
> Just to be sure, I'll show my config below:
>
>
>
> node cl1 \
>
>         attributes standby="off"
>
> node cl2 \
>
>         attributes standby="off"
>
> primitive drbd0 ocf:linbit:drbd \
>
>         params drbd_resource="mysql" drbdconf="/etc/drbd.conf" \
>
>         op start interval="0" timeout="240s" \
>
>         op monitor interval="20s" timeout="20s" \
>
>         op stop interval="0" timeout="100s"
>
> primitive drbd1 ocf:linbit:drbd \
>
>         params drbd_resource="www" drbdconf="/etc/drbd.conf" \
>
>         op start interval="0" timeout="240s" \
>
>         op monitor interval="20s" timeout="20s" \
>
>         op stop interval="0" timeout="100s"
>
> primitive drbd2 ocf:linbit:drbd \
>
>         params drbd_resource="zarafa" drbdconf="/etc/drbd.conf" \
>
>         op start interval="0" timeout="240s" \
>
>         op monitor interval="20s" timeout="20s" \
>
>         op stop interval="0" timeout="100s"
>
> primitive mysqlfs ocf:heartbeat:Filesystem \
>
>         params device="/dev/drbd0" fstype="ext4" directory="/var/lib/mysql"
> \
>
>         op start interval="0" timeout="60s" \
>
>         op monitor interval="20s" timeout="40s" \
>
>         op stop interval="0" timeout="60s" \
>
>         meta target-role="Started"
>
> primitive mysqlip ocf:heartbeat:IPaddr2 \
>
>         params ip="192.168.2.30" nic="eth0" cidr_netmask="24" \
>
>         op start interval="0s" timeout="60s" \
>
>         op monitor interval="5s" timeout="20s" \
>
>         op stop interval="0s" timeout="60s" \
>
>         meta target-role="Started"
>
> primitive wwwfs ocf:heartbeat:Filesystem \
>
>         params device="/dev/drbd1" fstype="ext4" directory="/var/www" \
>
>         op start interval="0" timeout="60s" \
>
>         op monitor interval="20s" timeout="40s" \
>
>         op stop interval="0" timeout="60s"
>
> primitive zarafafs ocf:heartbeat:Filesystem \
>
>         params device="/dev/drbd2" fstype="ext4" directory="/var/lib/zarafa"
> \
>
>         op start interval="0" timeout="60s" \
>
>         op monitor interval="20s" timeout="40s" \
>
>         op stop interval="0" timeout="60s"
>
> ms ms_drbd0 drbd0 \
>
>         meta master-max="1" master-node-max="1" clone-max="2"
> clone-node-max="1" notify="true" target-role="Started"
>
> ms ms_drbd1 drbd1 \
>
>         meta master-max="1" master-node-max="1" clone-max="2"
> clone-node-max="1" notify="true"
>
> ms ms_drbd2 drbd2 \
>
>         meta master-max="1" master-node-max="1" clone-max="2"
> clone-node-max="1" notify="true"
>
> colocation fs2_on_drbd inf: wwwfs ms_drbd1:Master
>
> colocation fs3_on_drbd inf: zarafafs ms_drbd2:Master
>
> colocation fs_on_drbd inf: mysqlfs ms_drbd0:Master
>
> order fs2_after_drbd inf: ms_drbd1:promote wwwfs:start
>
> order fs3_after_drbd inf: ms_drbd2:promote zarafafs:start
>
> order fs_after_drbd inf: ms_drbd0:promote mysqlfs:start
>

You either set a location constraint for mysqlip or use a colocation
and ordering constraint for it.

e.g.: colocation mysqlip_on_drbd inf: mysqlip ms_drbd0:Master
order mysqlip_after_drbd inf: ms_drbd0:promote mysqlip:start

> property $id="cib-bootstrap-options" \
>
>         dc-version="1.1.2-f059ec7ced7a86f18e5490b67ebf4a0b963bccfe" \
>
>         cluster-infrastructure="openais" \
>
>         expected-quorum-votes="2" \
>
>         no-quorum-policy="ignore" \
>
>         stonith-enabled="false"
>
> rsc_defaults $id="rsc-options" \
>
>         resource_stickyness="INFINITY" \

I wouldn't set INFINITY, it will cause problems, I'd give it a value
of 500 or 1000.

Regards,
Dan

>
>         migration-threshold="1"
>
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>
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>
>



-- 
Dan Frincu
CCNA, RHCE