Knowledge of the DB2 process model can help you determine the nature of a problem because it helps you to understand how the database manager and its associated components interact.
Most UNIX-based environments let you see a list of the current DB2 processes. For example, you can see if an application has an agent assigned to it, if the database server is up, or if a communication protocol's listener is up.
Unfortunately, you cannot identify these processes on the OS/2 and Windows operating systems because DB2 is implemented using a multithreaded model. If you use these operating systems, you may wish to ignore this chapter.