System Requirements

This document explains you what software you need to have already installed and where to get it, and what software is optional depending on your needs. Additionally this document touches on some thoughts to consider as it relates to database, application server and hardware requirements.

Version:

Expresso 5.5

Maintainer:

Sandra Cann

Introduction

Please see the detailed "Pre-requisites document" for more details on what you need to think about *before* you install Expresso. Expresso should run correctly on any OS that supports Java 1.4, and has been tested with Linux, Solaris, Windows 98 and Windows NT.

Expresso requires at least:

A Java 1.4 compliant compiler and runtime.
The Java Servlet API (version 2.3 or greater) must be supported by your web server application, or you must have a "plug-in" (such as JRun) that adds this support.
The JavaMail API packages (and the required Java Activation Framework)
A database that supports the JDBC standard and a suitable JDBC driver for that database.

Optional Jars

Firstly there is a 3rd party library download file onsite. This is for the src download - that is if you are not using the Expresso complete download. The latter includes the third party libraries as part of the distribution.

Expresso also has some optional features that you may want to download the appropriate 3rd party jars to take advantage of those features.

To use strong encryption you will need to download the "Bouncy Castle" cryptographic provider and install it in your WEB-INF/lib directory.
To use server side unit testing you may need to download the Cactus server-side unit testing framework. Cactus is a simple test framework for unit testing server-side java code (Servlets, EJBs, Tag Libs, Filters, ...). The intent of Cactus is to lower the cost of writing tests for server-side code. It uses JUnit and extends it. Cactus has been developed with the idea of automatic testing in mind and it provides a packaged and simple mechanism based on Ant to automate server-side testing. If you are running a servlet api version 2.3 compliant container such as Orion or Tomcat 4, then you do not need any additional jar files.

Note that all of the above links open in a new window.

System Performance

Since we get asked about what hardware is needed to support Expresso, here are a few perspectives from our users on performance.

Starting with about using or not Tomcat and JBoss in a production environment... In a big enterprise project, the cost of the application server is not very significant, and the tools and docs that come with some commercial app servers can improve your productivity (or decrease it.. but that's subject for another discussion). The same goes for the RDBMS. The choice will come from a simple question.. "Is it worth to invest on them?" the answers come mainly from the ROI time and the load the server will take. If the ROI for let's say Websphere + DB2 will be 10 years, and the load will be 2000 conections a day.. well, I guess it won't be the best choice, since Tomcat + JBoss + PostgreSQL will take that load easily, and the ROI will depend almost exclusively on the cost for developing the app. If the ROI will be one year, and the load will be 10,000 conections an hour, then you wouldn't want to save two bucks on the app server and RDBMS, since they will be quickly mortaged, and the slight gains in performance will make you earn money. The hardware and the tuning are also very important. And the way you design your EJBs and DB tables will greatly impact in performance too.

Finnally, the best choice is always the platform in which you feel the most comfortable working with. So what I mean by all this? You can have the best App server and RDBMS, but you make them run in a single processor PIII 650 with 256 MB RAM, and you must not be surprised if performances won't be great.. if the budget is restraint, then an open source server and RDBMS will let you use that money for buying yourself a quadri-Xeon with 2 Gigs of RAM, and it will work great. Make sure the Pentium processors are NOT Celeron processors as they're 'gimped' and will bite you as the load increases. Get as MUCH RAM as you can afford. I'm talking at least 1 Gb if you can take it.... in fact if a dual processor requires special memory that would cost more and you are on a budget then there 's a case for going with the Single processor and get more ram. You may want to get two hard drives. Put the operating system and web server stuff on one hard drive, put the database running on the other. It will allow the system to simultaneously serve files and database reads. It'll be worth it, especially since IDE drives of small-medium capacity are fairly cheap. Don't worry about RAID so much as a decent backup device when if you're trying to get things down price wise. If you end up going with a Single processor, try getting an AMD XP chip instead of a Pentium 3... better performance for the same price. [If your vendor makes a model like that, of course ]. Do a lot of research into your network card. That can make a huge difference. See if people are having problems with it on the newsgroups.

The same goes for the EJBs and DB tables. if you have 20 joins between tables, and your EJBs are very fine grained, so your app server spends 90 % of the processor time in creating and destroying objects, you can be sure that your app won't be lightning fast, and no Weblogic or Websphere will help that.

So what's the performance like. Here's the result as reported by one community member, "had made a test with the eContent and we can handle 120 Million page impressions per month (24 millisecound to generate one HMTL page from XML & XSLT!!!!) on a dell server with 512 MB ram and one 1,4 GHz cpu. *Wow!!!*."

We done a lot of performance improvements since this quote. If you have some benchmarks please share they with the community. You can send them to the maintainer of this document or post them to the user forum.

Conclusion

If you have any questions as it relates to system requirements we suggest you post them to the onsite forums. If you would like to contribute to this document please email us.