> I call this pattern a gateway - a separate process accepting
> input from the
> outside world and then passing the input through to a Session Bean.
> Absolutely no restrictions - it is just a client of the AppServer.
>
> Deployment is a little more complex - you have to ensure the
> process is
> continually running (or is restarted when/if it dies), and you have to
> recover if the AppServer goes away and restarts.
>
> Weblogic has a (vendor specific) mechanism for starting specified Java
> 'apps' when the AppServer starts (startup classes?).
>
> I have this mechanism in (serious) production environments, using HP
> OpenView to control re-starts etc. (other app managers would
> also be fine).
>
An out side agent to restart your RMI application??? What hoop jumping!
You are ambitious. :)
Amazing what folks are doing to deliver Singleton services and services
that don't serialize method calls, allow threads, File etc etc.
Another choice is, if you care about reliable/resiliant services where the
appserver and console support restart and fail over to another box
as an integral part of the appserver's rightful resiliency responsibility:
- Choose an appserver that supports resilient Corba/RMI services
- Configure that Corba/RMI service to be a singleton (or clustered) and
resilient within the domain (cluster).
- Vendors who support this, also support inter calling of EJB<-->Corba/RMI.
I added RMI in the above after the fact. I really don't consider RMI
to be an enterprise facility given that it lacks transparent resilient
stubs and resilient name service. Corba has the best resiliency
features.
You'll be dissappointed at how few products support the above reasonable
commercial requirement.
As much as I've hated the performance loss of moving simple Singletons
(logging, eventing, helper classes) outside the local VM to a seperate
VM and service (Corba) I'm forced to consider the this as the only truely
commercial design that's reliable and resiliant and the best choice
given these gapping flaws in the EJB spec.
<complaining>
I don't consider the appserver SB cache/pool size limit 'tricks' to be
good or portable designs including RMI which isn't supported as a
resilient or clusterable service by the EJB spec and thus all vendors.
I think EJB designers need to complain to the vendors about no good
solutions for: Singlton, debug logging per bean, BL events (IE support
for JMX from the container or context), resilient RMI and Corba.
;-(
</complaining>
Curt
Curt Smith
Z-Tel
email: [EMAIL PROTECTED]
work: 404-237-1166 x182
FAX: 404-237-1167
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
