This month’s BCS ‘iT NOW’ magazine contains a short anonymous article entitled The problem with SOAs. It does a reasonable job of explaining what an SOA is at a high level, but I thought it might be worthwhile briefly discussing it in the context of WebSphere ESB. As with many discussions of SOA, the majority of the article is spent discussing Web Services as the invocation mechanism for SOAs. At the end it mentions JMS as a possible alternative invocation method, but says ‘implementation may be problematic’ (although doesn’t really explain why).
To clarify, WebSphere ESB can be used to construct SOA architectures that are based around Web Services or JMS, or a combination of both. Simple-to-implement SCA default bindings can also be used within the scope of an ESB cell. In fact, because it is built around SCA, the invocation mechanisms are partly abstracted away: when you construct mediation flows in WebSphere Integration Developer, all these types of ‘bindings’ appear very similar. All of this makes WebSphere ESB a powerful tool for linking together traditional messaging systems, based around JMS, with synchronous Web Services, as well as other types of services and systems using WebSphere Adapters.
For more information on SCA and why it’s useful, please see Richard Brown’s excellent posting on this topic.
As with many of my other postings about WebSphere ESB, most of what I said above also applies to WebSphere Process Server, as it is a functional superset of WebSphere ESB.