Re: [mod_cluster-dev] [Fwd: mod-cluster and domains]
by Paul Ferraro
On Fri, 2009-07-17 at 16:51 +0200, Bela Ban wrote:
> Resent as the mod-cluster list didn't receive it
>
> -------- Original Message --------
> Subject: mod-cluster and domains
> Date: Fri, 17 Jul 2009 13:34:09 +0200
> From: Bela Ban <bban(a)redhat.com>
> To: mod cluster <mod_cluster-dev(a)lists.jboss.org>
>
>
>
> I've got a few questions regarding the functionality of mod-cluster:
>
>
> *#1 Does mod-cluster support domains with sticky sessions ?_
>
> _*I recall discussing this on *this* mailing list, and IIRC Paul
> confirmed that mod-cluster supports domains with sticky sessions. I
> actually tried this out and t worked.
>
> I just need a quick confirmation on this. For config details, I'll go
> and re-read the archives.
Yes.
> *#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.
> *#2a: How do I know when all sessions of all nodes of a given domain
> have expired ?*
>
> This is necessary to know when I can shut down all nodes of a given domain
mod_manager reports the number of active sessions per node. This logic
isn't completely accurate - as it defines an "active" session as one
that was accessed within the last 5 minutes.
To get accurate active session counts from each server in a domain,
you'll need to verify the activeSessions attribute of the individual
jboss.web:type=Manager,* mbeans via jmx-console, or similar.
The plan is to implement stop(...) management methods (i.e. for graceful
shutdown) that disables the node, waits for all sessions to drain, then
stops the node.
We'll allow this per domain as well.
> *#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.
> *#4 Enabling an entire domain*
>
> When all nodes in a domain have been started as disabled (step #3), I'd
> like to tell the httpds to enable all (or a selected set of) webapps in
> a given domain, in all nodes of that domain. Is this possible ?
In general, we have not yet implemented per-domain management functionality.
I'll create JIRAs for these.
> The point behind these 4 questions is that I want to demo how to disable
> a domain, shut it down, upgrade the HW/SW, start it again, and re-enable it.
>
> --
> Bela Ban
> Lead JGroups / Clustering Team
> JBoss
15 years, 5 months
- 3
- 2
Re: [mod_cluster-dev] [Fwd: mod-cluster and domains]
by jean-frederic clere
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-e...).
>
>
>
>>>> *#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
15 years, 5 months
- 2
- 1
mod-cluster and domains
by Bela Ban
I've got a few questions regarding the functionality of mod-cluster:
*#1 Does mod-cluster support domains with sticky sessions ?_
_*I recall discussing this on *this* mailing list, and IIRC Paul
confirmed that mod-cluster supports domains with sticky sessions. I
actually tried this out and t worked.
I just need a quick confirmation on this. For config details, I'll go
and re-read the archives.
*#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 ?
*#2a: How do I know when all sessions of all nodes of a given domain
have expired ?*
This is necessary to know when I can shut down all nodes of a given domain
*#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 ?
*#4 Enabling an entire domain*
When all nodes in a domain have been started as disabled (step #3), I'd
like to tell the httpds to enable all (or a selected set of) webapps in
a given domain, in all nodes of that domain. Is this possible ?
The point behind these 4 questions is that I want to demo how to disable
a domain, shut it down, upgrade the HW/SW, start it again, and re-enable it.
--
Bela Ban
Lead JGroups / Clustering Team
JBoss
15 years, 5 months
- 1
- 0