[ClusterLabs] Creating a rule based on whether a quorum exists

Les Green les at greemo.com
Mon May 30 09:13:47 EDT 2016

Hi All,

I have a two-node cluster with no-quorum-policy=ignore and an external
ping responder to try to determine if a node has its network down (it's
the dead one), or if the other node is really dead..

The ping helps to determine who the master is.

I have realised in the situation where the ping responder goes down,
both stop being the master.

Code can be seen here: https://github.com/greemo/vagrant-fabric

I currently have the following rule which prevents a node becoming a
master unless it can access the ping resource. (I may add more ping
resources later):

      <rsc_colocation id="c_mysql_on_drbd" score="INFINITY"
rsc="g_mysql" with-rsc="ms_drbd_mysql" with-rsc-role="Master"/>
      <rsc_location id="l_drbd_master_on_ping" rsc="ms_drbd_mysql">
        <rule role="Master" score="-INFINITY" boolean-op="or"
          <expression attribute="ping" operation="not_defined"
          <expression attribute="ping" operation="lte" value="1000"
type="number" id="l_drbd_master_on_ping-rule-expression-0"/>
      <rsc_order id="o_drbd_before_mysql" score="INFINITY"
first="ms_drbd_mysql" first-action="promote" then="g_mysql"

I want to create a rule that says "if I am not in a quorum AND I cannot
access all the ping resources, do not become the master". I can sort out
the ping part, but how can I determine within a Pacemaker rule if I am
part of a quorum?

I have thought to set up a cron job using shell tools to query the CIB
and populate an attribute, but surely there has to be an easier way...

Hopefully, Les

More information about the Users mailing list