From: Ken <ken.cavanaugh_at_oracle.com>
Date: Tue, 06 Jul 2010 11:04:02 -0700

The basic plan for IIOP failover is to fetch the current IIOP port information for the cluster
from the config objects (basically domain.xml) whenever the ORB is notified by GMS that
an instance in the cluster has gone down, come back up, or been added or deleted to the
cluster.  In order to do this, I need to understand exactly how the port information is
represented in GF 3.1. 

I think this is similar to the GF 2.x structure, except that there the GMSLifeCycle code
(in addIIOPEndPoints) added the endpoint info to the GMS distributed cache.  In discussions
with Joe Fialli, we realized that this step is redundant, since the config object will be
updated before the ORB is notified by GMS about a change in the cluster status.
So the ORB can update the ports that go into the IOR simply by fetching the appropriate
config objects.

We have the following structure in the config objects:

• (1)Domain
  
• (1)Clusters
• (*)Cluster (name, config-ref)
• (*)Server (ref)
• (*)SystemProperty
  

How do I determine  which cluster (name attribute?) applies to the current node?
Will it be possible to configure than one cluster configured in GF 3.1?
Assuming I know this, the config-ref and the server-refs give me the appropriate Server and Config
objects that I need from Servers and Configs, respectively.

I think I can get the Habitat by injection, then get the top-level admin objects by
Habitat.getComponent for Domain, Clusters, Servers, and Configs. 
I can get a Server using Servers.getServer(String),
a Cluster by looking in the getCluster() list (is there a cluster name or something else to
identify a particular cluster?), and a Config from Configs.getConfigByName.

• (1)Domain
  
• (1)Configs
• (*)Config
• (1)IiopService
• (*)IiopListener (port, id, address) where port is typically ${some property name}
• The ORB needs the port and id (to determine SSL/clear etc) and the node address from the server: the address here is the listener address, not the address used in the IOR

Once I have the correct config, the IiopListener port needs to be resolved in the context of a
particular Server, since the port value is a property name.  I think I can do this with an
org.glassfish.config.support.PropertyResolver, but that still seems to require code for parsing
${...}.  Is there a utility somewhere that handles this?

I'm trying to piece this together from the source code and whatever examples I can find.
GF admin is like a trackless wilderness with no maps for those of us that seldom visit that
part of the code.  Please comment on the above, and help me to correct any errors or
misconceptions that I may have.

Thanks,

Ken.