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

[Ruben Sajnovetzky]

Good example, thanks.
Not sure if is doable because we could have 10 servers and the idea to have
10 service instances could be tricky to admin :(

What about the other q, related with the usage of same name of devices and
mounting points?


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On 27-Sep-2011 7:25 PM, "Digimer" <linux at alteeve.com> wrote:

> Forgot to include an example;
> 
> This link shows RGManager/cluster.conf configured with two single-node
> failoverdomains (for managing the storage services needed to be running
> on both nodes in a 2-node cluster) and two failoverdomains used for a
> service that can migrate (a VM, specifially). It will hopefully be
> useful as a template for what you are trying to do.
> 
> https://alteeve.com/w/Red_Hat_Cluster_Service_2_Tutorial#Creating_the_Ordered_
> Failover_Domains

On 27-Sep-2011 7:18 PM, "Digimer" <linux at alteeve.com> wrote:

> On 09/27/2011 02:29 PM, Ruben Sajnovetzky wrote:
>> 
>> Hello,
>> 
>> I¹m 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 ³Central Server² and the others ³Collectors².
>>         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 ³/opt/app² and I want to monitor it in all them (i.e.:
>>                 different, separated, independent instances in separated
>> servers).
>>                 In Veritas we had ³fscentral² and ³fscollector², 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
>>           can¹t say ³collector 1 will be mounted as /opt1² or ³collector
>>         1 will have volume name as vol1².
>> 
>>     5. Second issue I have:
>> 
>>             How I can run the ³service² ³app collector² in more than one
>>     server simultaneously (in parallel)?
>>             Again, the option to have ³X² services for ³X² 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.
> 
> -- 
> Digimer
> E-Mail:              digimer at alteeve.com
> Freenode handle:     digimer
> Papers and Projects: http://alteeve.com
> Node Assassin:       http://nodeassassin.org
> "At what point did we forget that the Space Shuttle was, essentially,
> a program that strapped human beings to an explosion and tried to stab
> through the sky with fire and math?"