Choosing an AS in a NutShell J.MOLIERE-2004

Who am I ? ► Independant author/consultant  Cahiers du programmeur Java – tome 2 – Eyrolles 2003  Cahiers de l’admin – Eyrolles – a paraître – Comprendre et utiliser un serveur J2EE  Maintainer from the FAQ nntp://fr.comp.lang.java nntp://fr.comp.lang.java  Articles (Login/  Former of the mentor/J company

Introduction ► Goals:  Avoid vendor traps,  Avoid marketing effects,  Make a short-list from the essential questions,  Help you do the smart choice…

Managers key points ► TCO ► Budget ► Support?

Beyond the marketing… ► What does free means ?  Documentation  Support  Opening ► Don’t move license free costs to other poles..

Never again… ► You used proprietary software:  Don’t make twice the same error…  Don’t use proprietary extensions…  Use plain J2EE APIs ► E.g: EJB 2.0 & EJB-QL  Don’t use any QL-like language overriding these limits.

What is a software budget? ► Deployment :  License cost!!! ► But:  Development: training/documentation…  Administration:support/administration tools  Migrating from one version to another.  Tuning the server…

Engineering key points ► J2EE conformance ► Managing the risks ► Key features ► Administration ► Product evolution…

J2EE conformance ► Work in progress  JONAS 4.1 used as a reference for the Sun TCK.  Same thing for JBOSS… ► Final score :1-1 ?  May be but: ► UnifiedClassLoader from the JBOSS team could be a huge trouble for them…

J2EE key features ► TCK delivers a label from conformance so:  J2EE core features are implemented ► What TCK doesn’t check:  Clustering

Clustering in the J2EE World ► Choosing an AS for its clustering features:  Why not?  But beware: ► JONAS/JBOSS can do HTPP Session replication over Jetty/Tomcat but it’s a bad idea!!! ► JBOSS team claims that the only solution is Local interfaces usage !!! Where is distribution here? ► Please don’t rely on unreliable products (JavaGroups don’t scale well so don’t use it).

Clustering in the J2EE world ► Clustering tiers, common answers:  HTTP  MDB/SFSB ► Leaves a huge problem:  The RDBMS tier is not replicated…  So no real fault tolerance  No load balancing on this tier (the most critical one).

Clustering in the J2EE world ► So how to replicate the RDBMS tier?  Use vendor specific solutions (Oracle 10 HA)  Expansive solutions…  Or use C-JDBC!!! ► multi databases (heterogeneous parc) ► Cache ► Intelligent load balancing algorithm (from the several available)

Clustering in the J2EE World ► J2EE is the core node in heterogenous architectures:  ERP  Legacy systems .NET front-end ?  CORBA applications

Clustering in the J2EE world ► JMS is one of the major API ► Why ?  Delivering messages with delivery warranty is a tremendous need in HA applications (bank/financial/telecom)  Asynchronism is the better answer to overloaded architectures. ► JORAM is your friend…

Clustering in the J2EE world ► Deploying clusters:  JBOSS nice features (farming/singleton service in a cluster).  But: ► Farming not really usable in production (administrators tend to prefer scripts to automatic operations). ► Doesn’t fit well to large nodes number.

Administration ► Do not forget these daily tasks!!! ► JMX is the standard way:  Used as a communication bus in JBOSS but doesn’t bring us usable tools.  Far more complete in JONAS. ► Administrators love non GUI consoles  JBOSS doesn’t provide such tool..  man jonas admin!!!

Conclusion ► Choice is a weird thing but:  Logic must be your best friend  Beware of marketing  Remind your previous choices..  Consult your team before completing this process..  Take the one that fits your needs (and future needs).

Q/A ► It’s up to you now!!!

Resources ► ► ► ►

Thanks!!!

Resources