Hi folks,

i'm writing a proof of concept focused on Session EJB high availability, this proof is 
based on two simple Session EJB the first is a stateless and the second, obviously, 
stateful with a simple conversation logic; source code and deplyment descriptors 
follows.

To test EJB HA i've defined a JBoss cluster configuration made of three logical nodes 
running into DefaultPartition; a front end node FE1 running only a web application as 
client of remote EJBs; the other two back end nodes, BE1 and BE2, holds the same EJB 
package with clusterable tags sets to true.

The cluster, only for development purpose, is running onto a unique machine; 
configurations follows. The same cluster configuration has been tested in Linux (RH9) 
and Win2K with identical "unexpected" results.

Testing a front end node FE1 with Web app using HA-JNDI and only one back end node, 
say BE1, with EJB app, the cluster works fine with both kind of EJBs; but when turn ON 
the second EJB back end node BE2 ... the new BE2 node is recognized by the cluster, 
the stateless EJBs are still well balanced using default RoundRobin policy, the 
stateful EJB ... lets the cluster go 'crazy' in a unrepeatable way; it rarely works, 
the most fails; it seems to create an infinite number of stateful EJB instances going 
into a stack overflow exception on the other node respect the one is about to serve 
the request. 

Scenario example: 

1- the client on FE1 create a remote instance, the home created by HA-JNDI serves a 
new remote instance from BE1, 
2- the client start and consume a conversation with the remote instance, the EJB 
generates a random number, 
3- the client executes 'n' consuming calls to terminate the conversation then remove 
the remote instance, 

[All traces are from the Win2K run test, the Linux test results are equals ... :-( i 
was hoping in a Gates mistake !!!!]

this is an excerpts from trace ...

<<< 
see also messages
"SFSB prolem during state replication in HA cluster (2) ? (traces)"
"SFSB prolem during state replication in HA cluster (3) ? (source code and configs)" 
>>>

The mixed s.o. test (Linux + Win2K) has not be done ... i don't want to win another 
nightmare !!!

Until here this may seems a tutorial on how to test a cluster ;-) but ...

As from correctness of stateless EJB availability and balancing the cluster node 
communication seem to works,
the problem 'seems' to be about stateful EJB state propagation, should i configure 
some specific for sharing EJB states ?

Is there something wrong in 'cluster-service.xml' configuration ?

Can anyone advice me on the next serious action to put it at work ?

Bela, hey Bela ... i'm talking to You ;-)

P.S. Sorry for a so huge message, but is difficult to describe a so strange behaviour.


Marco.



View the original post : 
http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3829184#3829184

Reply to the post : 
http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=3829184


-------------------------------------------------------
This SF.Net email is sponsored by: IBM Linux Tutorials
Free Linux tutorial presented by Daniel Robbins, President and CEO of
GenToo technologies. Learn everything from fundamentals to system
administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click
_______________________________________________
JBoss-user mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/jboss-user

Reply via email to