users@glassfish.java.net

Re: automatically Starting a cluster after another cluster failed

From: legolas wood <legolas.w_at_gmail.com>
Date: Sun, 22 Apr 2007 21:50:13 +0430

Thank you for reply.

I have another question which is a bit more technical.

What is Glassfish mechanism for session, JNDI,... replication?

for example does it replicate all information into all instances memory or it store them in one central shared memory and other instances read from that memory?

Thanks



kedar wrote:
> I don't think clusters failing over other
> clusters is a good idea, because it will be
> hard to maintain consistency. If you have
> enough hardware, just create a cluster with
> instances in it and go on increasing its
> capacity in terms of scalability.
>
> Few Guiding Principles:
>
> - All instances in a cluster are homogeneous as far as
> configuration and applications/resources are concerned.
> In a given set of instances in a cluster, there is
> an inherent ability to fail over to each other, maintaining
> the state.
>
> - All clusters are individual sand-boxes and are designed
> to operate independent of others and GlassFish infrastructure
> does not have a built-in capability to fail over across
> clusters for aforementioned reasons.
>
> Kedar
>
>
> Daniel Cavalcanti wrote:
>> Just a thought.
>> You could implement your own load balance plugin to do that. Instead
>> of having the DAS start the "other" clusters, have all NA's and
>> instances already running and make your load balancer treat certain
>> instances as part of cluster A, B, or C. The SJSWS plugin file comes
>> with a sample round-robin load balancer source code. It's a little c
>> program (shared library) you need to write. You only have to
>> implement to methods.
>>
>> Daniel.
>> On 4/21/07, *Legolas Woodland* <legolas.w_at_gmail.com
>> <mailto:legolas.w_at_gmail.com>> wrote:
>>
>> Hi
>> Thank you for reading my post, any comment for this?
>> if this functionality is not present, is there any plan to add
>> this functionality to glassfish?
>> Thanks
>>
>> On 4/19/07, *Legolas Woodland* <legolas.w_at_gmail.com
>> <mailto:legolas.w_at_gmail.com>> wrote:
>>
>> Hi
>> Thank you for reading my post.
>> is it posible that DAS start a second cluster after one
>> cluster failed?
>> for example we have 3 cluster, each cluster has 3 node agent
>> and each node agent has 2 instances.
>> Now i want to have something like:
>> By default cluster one is under heavy load.
>> if cluster one failed by any means (disaster, power
>> shortage....) DAS start cluster two.
>> All instances are configured to work with sun java
>> web server
>> load balancer plugin. <==== I know how to configure load
>> balancer using that loadbalancer.xml file.
>> Thanks.
>>
>>
>>
>
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