Analyst advice: How to choose an app server

Here are their responses:

Christine Axton, senior analyst, Ovum

Choosing an application server is like buying a house - sure you can always move, but once you've paid the surveyors, paid the stamp duty, bought the furniture, painted the walls, installed the carpet and found out about the local area, it's not easy.

Theoretically, if you've bought a J2EE application server you can technically move to another one. However, you've invested time and money training developers and administrators in the intricacies of one type and you've paid the product licence, you've bought specific applications, tools and modules that 'work best' with this application server and you've written applications that run on this application server - they'll need tweaking if you're going to port them to another vendor's platform.

Application servers today have matured to the level where the functionality within the products from the top vendors will satisfy the needs of most organisations, so the most important concerns are really around the relationship with the vendor. Is their strategy aimed at an organisation of your size and complexity? What is their support and future release policy like, and where are they heading?

The other primary concern is whether you can easily adapt the skills you have in-house today to the skills required for this application server.

Alan Lawson, research analyst, Butler Group

I would view the deciding factor on the selection of an application server as being its ability to perform at an enterprise level. Because the core functionality of all application servers has now reached commodity status, vendors have to differentiate their products by using value-added features and/or services to enhance the provision of elements such as load balancing, or system management.

However, the performance of the core server product can often be overshadowed by the extensive use of enhanced features. The decision to implement the product should be therefore made on how well the product performs without the optional extras, meeting the demands of scalability, application portability and development, and of course security.

Jason Bloomberg, senior analyst, ZapThink

The J2EE application server market has largely been commoditised, so IT directors should consider the extras that come with the platform to determine which is right for their needs.

Typical items they should consider are ecommerce and personalisation capabilities, enterprise portal support, support for multiple interface devices (PDAs, mobile phones, etc), integration and web services capabilities, and legacy adapters, to name a few. IBM shops can benefit from their relationship with IBM, as well.

And in today's economy, every vendor is hungry, so striking the best deal with the vendor - for software, maintenance and professional services - can often be a critical factor in making an application server decision.

Phil Dawson, senior analyst, Meta Group

The biggest thing is integration. You've got to really consider how to take distinct applications for a specific service. If bridging several projects and integrating you've got to think how you're going to do that - in back office or at the application server.

Also price and position are key. With the core app server now bundled free as a commodity - for example with Solaris - the additional services, such as business logic, are now where the value is. What are you prepared to pay for?

Massimo Pezzini, VP software infrastructure, Gartner Group

Enterprise application servers will progressively complement, and over time possibly replace, traditional transaction monitors such as CICS or Tuxedo. Classic enterprise features such as high availability, scalability, transactional integrity, security and manageability will be of course important criteria along with standards support (J2EE, web services, XML etc).

However, availability of integration features will also be important owing to the growing trend of building so-called 'composite applications' - the blending of pre-existing systems with new developments.

New applications running on enterprise application servers will increasingly be exposed and published in the form of web services to enable other applications to support a plurality of access 'channels', including traditional PCs, web, mobile devices and voice. So support to a multi-channel architecture will be another important criterion.

Finally, given their strategic role, users will require vendors to provide not only a technically sound product but also support, services, consulting, and a variety of additional products (applications and tools) atop the basic app servers.

Steve Barrie, chief analyst, Bloor Research

Think of the app server as a delivery mechanism. It sits beneath the applications logic and serves up the functionality as it is required. This basic capability is common to all application servers and, unless there are specific needs within an organisation, it won't matter which one you choose.

The bigger issues will always be how well a particular app server fits into your existing IT infrastructure - it needs to support all your platforms and applications.

The biggest issue, though, is how easy it is to develop applications. Given that the core of all application servers should be the same, the competitive edge goes to those businesses that can develop their applications quicker and can make them work together better.

I would concentrate my effort on the development tools that support the app server rather than on the app server itself.