dev@glassfish.java.net

Re: config changes to a clustered instance?

From: Ken <ken.cavanaugh_at_oracle.com>
Date: Thu, 26 Aug 2010 16:18:52 -0700

Marina Vatkina wrote:
> Let me know if this is documented somewhere, but what I see is
> confusing (at least to me).
>
> If I change configuration of 1 instance in a cluster :
>
> % asadmin set in1.transaction-service.tx-log-dir=/Users/mvatkina/foo
>
> the change is recorded in the cluster's config in the DAS domain.xml
> (so it would apply to all instances after restart?) and in the in1's
> domain.xml under it's clustered-named-config. Does it mean that a
> clustered instance have no separate configuration? If not, why does
> the set operation succeed?
>
> thanks,
> -marina
>
In many cases, the config contains a variable rather than the actual
value, so that all nodes in
the cluster can share the same config. The actual value of the variable
is stored in a property
in the instance, rather than in the config. Admin (including most of
the internal APIs) expands
the variables behind the scenes, unless you use a special API to get the
raw unexpanded value.

Is this what is happening in your case? It's how the IIOP configuration
is handled across
a cluster, when each instance (which may be running on the same host as
another instance)
typically has a different set of ports, but there is only one shared
config, which includes iiop.

Ken.