Comparing the Versions

Now that I've discussed the high-level component architecture of the two versions of the WebSphere platform, Table 3-1 summarizes the key differences between them.

Table 3-1: WebSphere Platform Comparison

Component Type	WebSphere 4 Offering	WebSphere 5 Offering	Notes
Frontend HTTP plug-in	HTTP server plug-in (uses HTTP)	HTTP server plug-in (uses HTTP)	Both platforms offer the same capability via the plug-in.
Workload management/ high-availability HTTP capabilities	Domains, server groups, clones , plug-in	Cells , nodes, deployment manager, HTTP plug-in	Version 5 does away with server groups and clones.
Data storage	WebSphere administration repository, repository, application database, session database	XML-based configuration XML-based master repository, application database, session database, DRS	The key difference is in configuration storage medium in version 5.
Administration capabilities	X-based GUI, WSCP, XMLConfig	Web-based console, wsadmin	Version 5 has greatly expanded on the management control interfaces.
Server-to-server replication	Custom application, shared session database, load-balanced JNDI contexts	DRS, custom application, shared session database	DRS is a powerful tool featured in version 5. It provides memory-to-memory object replication technologies.