[Linux-cluster] How to run same service in parallel in RedHat Cluster 5.0

[Digimer]

On 09/27/2011 02:29 PM, Ruben Sajnovetzky wrote:
> 
> Hello,
> 
> I’m in the process of design a solution replacement to a Veritas
> implementation and have to find similar functionalities, not
> sure if this is doable in Red Hat Clutser:
> 
>     We have a distributed application that runs in several servers
> simultaneously and that application must run in a cluster environment.
>     The summary is as follows:
> 
>         1. Application has two different roles for the Servers, one we
> could call “Central Server” and the others “Collectors”.
>         2. Application has _one_ Central Server and _X_ Collector Servers.
>         3. Central Server + Collector Servers represents a set of
> servers that must be running all time and we want to implement
>            two sets in order to implement failovers between them.
>         4. _First issue I have_:
>                 Application is installed in _all servers_ at same
> location, let us say “/opt/app” and I want to monitor it in all them (i.e.:
>                 different, separated, independent instances in separated
> servers).
>                 In Veritas we had “fscentral” and “fscollector”, both
> with same device name and mounting point and that worked fine,
>                 (of course, both resources were part of different
> service groups and running in different servers).
>                 I tried to do the same here and got an error:
>                     
> 
>             clurgmgrd[9374]: <err> Unique attribute collision. type=fs
>             attr=mountpoint value=/opt
>              clurgmgrd[9374]: <err> Error storing fs resource
> 
>          Then, I assume should be a different way to implement this
>         resource? Notice that the number of Collectors is variable so I
>           can’t say “collector 1 will be mounted as /opt1” or “collector
>         1 will have volume name as vol1”.
> 
>     5. Second issue I have:
> 
>             How I can run the “service” “app collector” in more than one
>     server simultaneously (in parallel)?
>             Again, the option to have “X” services for “X” Collectors is
>     not a real option here.
> 
> Any idea will be appreciated!!!
> 
> 
>     Thanks

I've not read this carefully (at work, sorry), but if I grasped your
question;

For services you want to run on all servers;
- Defined a unique failoverdomain containing each node to run the
parallel services.
- Create the a service multiple times, each using the failoverdomain
containing the single target node.

For services to run on one node, but move on failure, create another
failover domain (ordered, if you want to set preferences) with the
candidate nodes as members. Then create a service and assign it to this
domain.

To provide your cluster.conf (or as much as you've crafted so far).
Please only obfuscate passwords if possible.

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Digimer
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