SST provides a common interface for startup and shutdown as described in Startup and shutdown. The interface for components which support startup and shutdown is found in the IuSstStartable interface.

The start up and shut down of parts of a running distributed system is difficult if not impossible to define in a general way. Each application has different requirements as to its execution state once an image is up and running. The problem is exacerbated by the fact that in Smalltalk, immediately after saving an image the virtual machine may exit or continue processing. That is, very little clean up work can be done at image save time.

To assist in the management of distributed applications, various SST components define options allowing you to control how the components are treated at image restart time. These controls are available on invocation handlers, object spaces, and application contexts.

While the details of each component's options can be found in the relevant section, in general they adhere to the following pattern. The configuration object associated with the component defines a restartMode. The setting of this mode determines the action taken at image restart time. Roughly speaking, the possible actions are:

Some components are restartable when an image is saved or started up afresh. Such components conform to the IdSstRestartable interface. The two methods that a component must provide are: