*Editor's Note: For Part I of this article, click here.

So, what else is there?

Now that ESB has become an established product category, numerous ESB vendors are competing on architecture, connectivity options, ease of use and Quality of Service issues such as continuous availability. Since organizations have been putting ESBs to work in the real world for a few years now, there is better clarity on what other infrastructure is necessary to build, deploy, manage, and extract business value from a widespread SOA across an organization.

The list is fairly substantial, but I’ll focus on a few of the important ones –

•        Web Services Management and SOA governance
•          Advanced Web Services (WS-*)
•          Complex Event Processing
•          Semantic Data Integration

The path toward SOA varies drastically at each company and sometimes even within different groups within the same company. An organization may have different development teams experimenting with Web services toolkits or using the Web services capabilities that come as part of their enterprise resource planning (ERP) system or their favorite application server environment. There may be multiple ESBs deployed or none at all.

A SOA Management platform provides visibility, security, control and policy enforcement across an end-to-end business process as the process executes across these many disparate environments. In addition to tracking Service Level Agreements (SLA), it may be able to provide business-level views in order to understand the business level impact of failures in a SOA. It may also be able to dynamically tune the SOA environment in order to enforce the SLA or enforce any other business policy. This is true whether the interaction styles are point to point or asynchronous and event driven. 

Depending on the implementation of the WSM platform, it may extend its reach across an ESB, application server platforms and database access; and it may even provide business level metrics and reporting at a business process level as the service execution traverses across different platforms, databases, protocols, and appliances (Figure 1).