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Building a Stable and Clustered J2EE Environment?

Posted by Cliff on from the sharing-sessions-between-multiple-machines dept.

royles asks: "I am working with several J2EE Application Servers and all seems fine until I start to scale and cluster. The goal is to ensure a web and EJB session is maintained across a pool of Application Servers. The level of complexity to achieve this straightforward requirement is proving too much. It quickly becomes evident that vendors claims of 'robust and scalable' go straight out the window in favour of extortionate support and consultant costs when the installation becomes large. Anybody else experienced this type of problem? What are other peoples experienceâ(TM)s in this area? Any recommendations on Application servers that âdo what they say on the tinâ(TM)? Any good online resources for achieving a highly scaled and robust solution?"

3 of 43 comments (clear)

  1. Re:JBoss does this now by danpat · · Score: 4, Insightful

    Actually, some appservers (WebSphere?) *do* have "click here to cluster" buttons.

    The problem is that they don't work.

  2. Clustering is hard, you can't avoid it by mlq · · Score: 5, Insightful

    Clustering *is* hard. And even the best application server in the world can't reduce that complexity. It can just try to not add any complexity of it's own.

    Front-end load balancing, internal load balancing policy, cache settings, fail-over settings, setting up the LAN correctly... these are all *extra* things you need to do under a clustered J2EE server that you don't need to worry about normally. Clustering is hard

    Having said that, I've been involved in commercial projects using clustering under Weblogic and JBoss. We have been able to get them going without too much trouble.

    Also, some things J2EE allows some things in non-clustered mode that it explicity warns won't work in clustered mode. For example, objects in Sessions must be Serializable when clustering.

    =Matt

  3. Re:Are EJB's really worth it? by Anonymous Coward · · Score: 4, Insightful
    It comes down to picking the right technology for the job.. and your team. JDBC, JDO, OR-Mapping, EJB, etc all provide good tools to complete the job.

    Agreed, but in my opinion any application which needs heavy multi-user data processing (think OLTP) is better served with the more "traditional" way of doing things: let the RDBMS do the transactions and cacheing, because they do it best. Call me a data modeler or SQL buff you like, but I still fail to see the advantages in letting the "application server" do these kind of things.

    About the only thing I see useful in EJB (vs. POJO+JDBC) is that they give you the networking infrastructure to make them remotely callable, so that you don't have to mess with RMI or the like.

    A good article I read recently by Martin Fowler, "Domain Logic and SQL" covers some of these points, and reinforces my opinion that neither EJB nor any other O/R mapping tools are suited for heavy OLTP apps. Or am I missing something?