Creating custom services

You can create one or more custom services for an application server. Each custom services defines a class that is loaded and initialized whenever the server starts and shuts down. Each of these classes must implement the com.ibm.websphere.runtime.CustomService interface. After you create a custom service, use the administrative console to configure that custom service for your application servers.

About this task

1. Following is a list of restrictions that apply to the product custom services implementation. Most of these restrictions apply only to the initialize method:
2. The initialize and shutdown methods must return control to the runtime.
3. No work is dispatched into the server instance until all custom service initialize methods return.
4. The initialize and shutdown methods are called only once on each service, and once for each operating system process that makes up the server instance.
5. Initialization of process level static data, without leaving the process, is supported.
6. Only JDBC RMLT (resource manager local transaction) operations are supported. Every unit of work (UOW) must be completed before the methods return.
7. Creation of threads is not supported.
8. Creation of sockets and I/O, other than file I/O, is not supported.
9. Running standard Java™ Platform, Enterprise Edition (Java EE) code, such as client code, servlets, and enterprise beans, is not supported.
10. The Java Transaction API (JTA) interface is not available.
11. This feature is available in Java EE server processes and distributed generic server processes only.
12. While the runtime makes an effort to call shutdown, there is no guarantee that shutdown will be called prior to process termination.
13. JNDI operations that request resources are not supported.