[mod_cluster-dev] [Fwd: mod-cluster and domains]

jean-frederic clere jclere at redhat.com
Mon Jul 20 08:31:25 EDT 2009


On 07/20/2009 01:09 PM, Bela Ban wrote:
>
>
> jean-frederic clere wrote:
>>> *#2 Disabling an entire domain*
>>>>
>>>> I want to disable not just 1 node in a domain, but all nodes in a given
>>>> domain. Is this possible ? If so, I'd assume this is done through
>>>> mod-cluster-manager ?
>>>
>>> This is not yet possible.
>>
>> There is a JIRA for his one. (MODCLUSTER-50)
>
> I see that this issue is not assigned to a release. When will this be
> done ?
>
> Or is there a discussion as to whether this should be done on the AS
> side rather than the httpd side ?

I am working on a command in /mod_cluster-manager that applies to all 
the nodes that belong to the domain. (Something like: 
http://localhost:8000/mod_cluster-manager?nonce=f33d6218-bfef-4d5f-b69f-efa03805e9fc&Cmd=ENABLE-APP&Range=DOMAIN&Domain=dom0).

>
>
>
>>>> *#3 Starting an entire domain in disabled mode*
>>>>
>>>> I want to start all nodes, one by one, in a given domain as *disabled*
>>>> (all webapps). Is it sufficient to just start all nodes as disabled
>>>> ? Is
>>>> it possible to start a node in disabled mode at all ?
>>>
>>> This is not possible, atm.
>>
>> We should need a table (shared information) on the domain and for the
>> moment the domain is just an information of the node
>
> Don't we need this info in the mod-cluster module ? I thought this is
> needed to pick sticky sessions on failover *within* a domain...

Yes but the logic is to look for the node corresponding to the sessionid 
and then to look for another node that belongs to the same domain.

>
>
>>>> *#4 Enabling an entire domain*
>>>
>>
>> It is "easy" to add a command in the mod_cluster-manager that disable
>> all the nodes corresponding to a domain. The scenario of the demo
>> would be:
>> 1 - disable domain x
>> 2 - show that an existing session still uses the domain.
>> 3 - show that a new session goes to another domain.
>> 4 - stop the domain (HW/SW).
>> 5 - show that an existing session give an error (sticky) or failover
>> (if not sticky).
>> 6 - start it again and show that it is re-enabled.
>
> I guess so. But when I talked to Brian last week, we concluded it would
> probably be better to disable a domain from the AS side, e.g. using
> JOPR. Then AS would tell httpd.
>
> However, I think being able to do this in mod_cluster_manager as well is
> helpful, e.g. for the above demo

Ok I am working on it.

Cheers

Jean-Frederic


More information about the mod_cluster-dev mailing list