Two of the components in the reference configuration, Portal Server and Access Manager, run in web containers. The Java ES component set gives you the choice of using either Sun Java System Web Server or Sun Java System Application Server for a web container.
You need to consider both technical and non-technical factors when you choose a web container.
The following technical factors address the abilities of the different containers to run different types of portal content:
Portlets and providers are Portal Server mechanisms for building presentation channels that can aggregate content from other applications. If your plans include developing portlets or providers that use Java EE APIs that are not supported by Web Server, such as the Enterprise JavaBeans (EJB) or Java Connector Architecture (JCA) interfaces, then you must use Application Server as your web container.
Web Server 7.0 supports a lightweight mechanism for HTTP session failover. This mechanism can be eventually used to enable portlet session failover in the same way that HADB and Application Server clusters enable such failover. However, this new feature of Web Server and its impact on the reliability, security, and performance has not yet been fully analyzed.
A reference configuration guide that documents a portal service deployment on Web Server does not yet exist.
If none of the technical factors are decisive for your organization, the following non-technical considerations could prove decisive:
Does your organization have existing standards for a web container? If so, you are likely to use that web container to implement the portal service reference configuration.
What does a price-to-performance comparison of the web containers reveal? Your organization might choose a web container based on the cost of the licenses that are needed to support the organization's user base. Your organization might have a volume discount agreement with a vendor that affects this decision.
Your organization might have support agreements with a web container vendor.
You might want to choose the same web container for all elements of your portal service even if you are not colocating Portal Server instances and portal channel applications. For example, if you have portal channels that are running in Application Server, you might want to deploy Portal Server in Application Server for the sake of consistency.
If there is no compelling reason to use Application Server in your portal, Web Server can be easier to administer.