The monitoring of a worker process by an executive process. A worker process
periodically sends a signal to an executive process, such as via a call to a heartbeat
interface, which receives the signal and determines whether the worker process
is improperly functioning. If the worker process is improperly functioning, the
executive process terminates the worker process. The executive process may also
examine the worker process for diagnostic purposes before terminating, or returning
control to, the worker process.