when to use an application server

[sattyani]

I would like to understand when should an application server be considered for an enterprise application.

To me it seems that everything (except for EJBs) can be handled by Spring (including spring modules) and a simple web container like tomcat

If this is the case, why do we still need application servers?

Please clarify.

Thanks

[guznik]

As I understand, Spring can indeed provide all the functionality required by most enterprise users, and there is no reason for new Java enterprise applications to be build using EJB and not Spring. However EJB servers have been around longer than Spring, and not all users would like to convert their (possibly huge) applications to another technology.
Furthermore, the JEE server vendors push their products both through the JCP by creating JSRs that should be easier to use than Spring configuration and API and by providing "suites" of JEE servers that integrate with the other products of the vendor (such as Oracle SOA suite and RedHat Enterprise Middleware).
My answer to the question "When should a JEE server be used instead of Spring (and possibly a Servlet container)?" is when the application server can provide some functionality that you require and is not provided by Spring, or when the application server reduces the overall complexity of your application.

[sattyani]

Thanks Gabriel for your reply

[unsu]

I have exactly the same question. I have been working with WebSphere for the last 6 years and now playing around with Spring (pretty new to Spring).

The most features provided by app servers come with Spring or its extensions.

Would Spring have some issues with scalability/clustering?
I dont think so as I came accorss Rod's post about some banks in France or the UK heavily using Spring for the financial transactions.

So why oh why would anyone use a heavy weighted app server.

Can anyone think of a good reason I fail to see?

Thanks

[Miki.Gevirtz]

Would Spring have some issues with scalability/clustering?

Spring doesn’t address this issue. I don't think Spring should/want to help us managing clustering.
But if you need to manage clustering I don’t know how you can avoid using heavy application server.
Anybody know how using heavy application server can be avoided(in a clustring envirment?

[GuyPardon]

Hi,

Have a look at these:

http://www.atomikos.com/Publications...licationServer

http://www.atomikos.com/Publications...ionsWithSpring

http://blog.atomikos.com/?p=36

http://blog.atomikos.com/?p=29

Best

[travism]

Can anyone think of a good reason I fail to see?

Thanks

Organization and application size may determine if you roll with a simple container (like tomcat) or something more substantial like WebSphere, JBoss, etc. It may not be at the discretion of the developer or development team.

My company uses WebSphere because they want support from IBM. They can hire certified/trained people to manage the WebSphere setups apparently a lot easier than they can for Tomcat. In addition to the support, they wanted a full-blown application server over a simple container because they figured the full application server can do everything the simple container can do but the simple container can’t do everything the application server can do. Due to organization size, they just wanted to standardize on one server that fits all.

I’m not singing the praises of WebSphere or slamming Tomcat here. To be honest, I don’t know a single application at my company that uses EJBs or anything more than what Tomcat offers (tomcat + axis). If I had my choice, I’d use Tomcat just for speed and simplicity purposes.

[rigby]

Hi,

Have a look at these:

http://www.atomikos.com/Publications...licationServer

http://www.atomikos.com/Publications...ionsWithSpring

http://blog.atomikos.com/?p=36

http://blog.atomikos.com/?p=29

Best

These are great, thank you!