[ClusterLabs] Multiple apache services running

[Ken Gaillot]

On 07/29/2015 08:05 AM, Vijay Partha wrote:
> Hi.
> 
> Victor, Whatever you said i had tried and got it working. Thank you.
> 
> Could you guys answer the following questions please?
> 
> 1.) I have 2 apache services running on the same node. If the services go
> down can pacemaker restart it?

Yes, that's what pacemaker is for :)

If by two services you mean two server instances of apache, then you
would configure two apache resources in pacemaker. If you mean two web
apps running in one apache server, you'd configure one apache resource
in pacemaker.

You would also need a monitor operation, which tells pacemaker to
periodically check the health of the service.

The migration-threshold and on-fail options determine what the cluster
does on failure. See the documentation for possible values, but the
default behavior is to try to restart the service on the same node.

The documentation for all the options is at
http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html-single/Pacemaker_Explained/index.html

> 2.) I have 2 apache services running on different nodes. Can i control both
> the resources from a single node by making use of pacemaker?

The various cluster tools work from any node, to affect any or all
nodes. Most commonly you'd use one of the high-level cluster shells
(crmsh or pcs). They have commands to enable/disable a resource, move a
resource to a different node, put a node in standby mode, etc.