Re: [xmlblaster-devel] Get connection states of connected nodes...

[Marcel Ruff <mr at marcelruff.info>]

Matthew Sargent wrote:
> Hi,
>  
> We are using the simple domain to master mapping and have setup 
> several mater/slave relationships. I would like to test if the 
> xmlBlaster instance I am connected to is further connected to others 
> in the cluster. I have a list of domains that I am making 
> subscriptions to and would like to use those to figure out if the 
> masters associated with each particular domain is connected. I see 
> many examples if you already have the master node id, but is there a 
> way to get the master node id for a domain so I can use that to query 
> the connection state?
Hmm, probably not out of the box ...

What you can certainly to is to register a native plugin in 
xmlBlasterPlugins.xml,
you can take a copy of org.xmlBlaster.engine.EventPlugin.java as a base 
and throw
out everything you don't need.
Find the code line where
 this.engineGlob = ...
is assigned.
With this you can call

  ClusterNode[] nodes = 
this.engineGlob.getClusterManager().getClusterNodes();
  for (int i=0; i<nodes.length; i++) {
     ClusterNode node = nodes[i];
     node.getConnectionState();  // See javadoc, marks alive, polling
     node.getId();               // the nodes name


Now you know the cluster nodes and if the connection is alive.

On the other side note that the EventPlugin implements 
I_SubscriptionListener.
With this listener you get notifed about all coming and going subscriptions:

 public void subscriptionAdd(SubscriptionEvent subscriptionEvent) {
     SubscriptionInfo subscriptionInfo = 
subscriptionEvent.getSubscriptionInfo();
     String domain = subscriptionInfo.getKeyData().getDomain();
     ...
 }
 public void subscriptionRemove(SubscriptionEvent subscriptionEvent) {
   ...
 }

Now you know about all subscribed domains.

You could now publish a PtP message to the clients interested or better 
publish the current list
to a topic (say oid="myCurrentDomainList") where your clients retrieve 
it from with get().

regards
Marcel


>  
> I would like to use the con.get() to gather this information 
> periodically so I can report on connection status.
>  
> Thanks,
>  
> Matt