Hi!

What about this: Run a ping node for a remote resource to set up some score 
value. If the remote is unreachable, the score will reflect that.
Then add a rule chink that score, deciding whether to run the virtual IP or not.

Regards,
Ulrich

-----Original Message-----
From: Users <users-boun...@clusterlabs.org> On Behalf Of Alexander Eastwood
Sent: Wednesday, December 6, 2023 5:56 PM
To: users@clusterlabs.org
Subject: [EXT] [ClusterLabs] Prevent cluster transition when resource 
unavailable on both nodes

Hello, 

I administrate a Pacemaker cluster consisting of 2 nodes, which are connected 
to each other via ethernet cable to ensure that they are always able to 
communicate with each other. A network switch is also connected to each node 
via ethernet cable and provides external access.

One of the managed resources of the cluster is a virtual IP, which is assigned 
to a physical network interface card and thus depends on the network switch 
being available. The virtual IP is always hosted on the active node.

We had the situation where the network switch lost power or was rebooted, as a 
result both servers reported `NIC Link is Down`. The recover operation on the 
Virtual IP resource then failed repeatedly on the active node, and a transition 
was initiated. Since the other node was also unable to start the resource, the 
cluster was swaying between the 2 nodes until the NIC links were up again.

Is there a way to change this behaviour? I am thinking of the following 
sequence of events, but have not been able to find a way to configure this:

 1. active node detects NIC Link is Down, which affects a resource managed by 
the cluster (monitor operation on the resource starts to fail)
 2. active node checks if the other (passive) node in the cluster would be able 
to start the resource
 3. if passive node can start the resource, transition all resources to passive 
node
 4. if passive node is unable to start the resource, then there is nothing to 
be gained a transition, so no action should be taken

Any pointers or advice will be much appreciated!

Thank you and kind regards,

Alex Eastwood
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