Choosing the Right Web Services Management Platform

s companies begin to implement Web services, IT managers are being confronted with the long-term ramifications of their deployment. Namely, management and support of Web services will ensure that they are well integrated, scalable, and maintainable. It is rare to find an organization that has considered these issues adequately in their current Web service implementations.

If you take only a cursory look at current Web services architectures, you might assume that once a Web service is deployed it can remain a viable entity. Pull the covers back and support issues become evident, such as:

• What happens if the service crashes?
• What happens if service resources become consumed?
• What happens if performance becomes unacceptable?

And there are more concerns where those came from. Because Web service environments are inherently more intricate, it's unlikely that developers will be able to create a management model that can suit every service. For example, some services can return results through computation done right at the location of the service. However, most Web services need to get their results from databases or other applications within the corporate firewall, and this adds to complexity, vulnerability, and the potential for elements to fail. IT administrators in this position may even want to bring in developers with expertise to diagnose and fix problems in a production environment, although this adds to the overall cost of the service.

Outline Key Functional Requirements
It is useful to separate out the management of the Web service from the management of the platform on which the service runs (the Web services platform). Think of the Web services platform as the interpreter of SOAP messages on their way to the Web service itself. By making use of its understanding of SOAP messages, the Web services platform can help the developer by taking over parts of the management functions.

Many vendors have Web services platform products on which developers will build their Web services, and those vendors will also supply some management capabilities with their products. However, developers cannot rely solely on the management features that come with the platform; you'll need to build some extra functionality to ensure your Web service is indeed manageable.

The key concerns in managing Web services begin with runtime instantiation and responsiveness to requests. These issues include:

• How the Web service can be instantiated or started up
• How multiple instances of the Web service may be handled concurrently
• How the load is being dealt with—by one instance or shared across those instances
• How any instance of a Web service may be shut down
• How the operations staff will monitor the stability of a running Web service at any time
• How the loading characteristics on that Web service can be discovered and presented to a manager
• How the operation of the Web service can be changed

In order for management data to be extracted, a Web service must conform to certain interfaces, or rules. These rules will be the "management interface" to the Web service and are made up of appropriate responses to messages for: