Re: Questions on Geronimo clustering support

[Jules Gosnell]

Alan D. Cabrera wrote:
 

-----Original Message-----
From: Jules Gosnell [mailto:[EMAIL PROTECTED]
[EMAIL PROTECTED] wrote:
   

Hi,
I am trying to get a feel for how EJB/JNDI clustering will be
     

implemented
   

in Geronimo and when it might be implemented.
I remember reading somewhere in the mail archives that the
     

clustering
 

module in Geronimo has been abandoned and that ActiveCluster will be
     

used.
   

Is it envisaged that another clustering module will be developed or
     

the
 

existing one changed?
Is EJB/JNDI clustering planned to be supported in the Geronimo 1.0
     

release
   

or is this non-essential functionality that will be in a later
     

release?
 

>
> Is the WADI project planning on providing EJB Tier clustering in
addition
> to  Web Tier clustering?
>
Yes and No :-)
I have spoken to some of the OpenEJB people about pushing WADI state
migration and replication technology back and underneath OpenEJB as
well, and they seem happy with that, but no concrete moves have been
made in that direction, as I am still hardeining the code in WADI - I
   

am
 

not expecting this to be in the first Geronimo release, as clustering
   

is
 

not a required piece of the spec.
As for the JNDI side of things, I have given it some cursory thought,
but no serious consideration. I am waiting to see how the state
replication technologies that we shall use will pan out. I am aware of
how other clustered EJB impls work, so that is a good starting point.
   

I
 

wasn't intending do to this piece of work myself, and haven't spoken
about it to David Blevins or the other OpenEJB people....
   

I'm curious.  What's the underlying protocol that WADI uses to maintain
its state/group?  I did a quick cursory look and couldn't find anything.
 

in the only release to date - there is no 'group', you just multicast if 
you get a request for session that you do not have - an exceptional 
case. If another node owns the cluster it lets you know and you then 
arrange its migration across a connection....

in cvs, WADI is currently using activecluster on top of activemq. You 
send a message to the cluster destination and wait for a 
message/connection to come back to you within a specified timeout.

Jules
Regards,
Alan
 


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