WebSphere Application Server - Attach existing AppSrv to an existing cluster

This is Interesting: Free IT Magazines  
Home > Archive > WebSphere Application Server > September 2005 > Attach existing AppSrv to an existing cluster





You are viewing an archived Text-only version of the thread. To view this thread in it's original format and/or if you want to reply to this thread please [click here]

Author Attach existing AppSrv to an existing cluster
Ben_

2005-09-26, 7:50 am

Hello,

From the console, it's possible to add an existing Application Server to a
new Cluster.

But it looks like I cannot attach an existing Application Server to an
*existing* Cluster.

Is it possible somehow (wsadmin ?) ? Or they did not implement it because it
does not make sense (but it does to me, so I'd be missing something then :-)
?

Thanks.



David Currie

2005-09-26, 7:50 am

It's not possible because it doesn't make sense. All of the servers in
the cluster share an identical configuration. How would you implement
adding an existing server to the cluster? Throw away all of its
configuration so that it is the same as the rest of the cluster (in
which case why not just create a new server in the existing cluster)? Or
make the whole cluster the same as the new joiner (in which case why not
just create a new cluster based on that server)?

Regards,
David
Ben_

2005-09-26, 6:04 pm

But they do not and cannot have the same configuration... Or am I wrong ?

For example, a member is on a small Windows box vs. the other is on a
high-end multi CPU Unix with plenty of RAM. You'll want to adapt the heap
settings, thread pools, cache sizes, etc.

Anyway, after you create a Cluster Member, you can configure it how you like
it...


David Currie

2005-09-27, 7:59 am

OK - so I should say that the application configuration is common across
the cluster. Is much of the server specific configuration not dependent
on the applications that you are running though?

David
Ben_

2005-09-27, 5:57 pm

Basically, the issue is a matter of convenience.

The question came while I was thinking at the necessity or not to foresee a
Cluster definition when an application has only one running copy (and thus
Application Server).

Imagine we have a regular Application Server (vs. Cluster / Cluster Member)
and we realize a second Application Server is necessary to cope with the
load.

So, I need to make a Cluster with a Cluster Member taking the existing
Application Server as template.

Then I have two Application Servers. But the two are not in the Cluster...

So, I have to make another Cluster Member and delete the non-clustered one.

Waste of time, isn't it ?

So, to avoid this, the solution is to create a Cluster definition even if
there is only one Cluster Member.

But again it's a waste of clicks if no additional Cluster member is ever
required.

Why not simply have the ability to "promote" an existing Application Server
into a Cluster ?


Sponsored Links






Free braindumps | Software forum | Database administration forum

Copyright 2003 - 2008 webservertalk.com