Started task
A long-running program that the system starts and leaves running, rather than a job that runs once and finishes.
Also written STC, started procedure
A started task is a piece of work that begins when the system is brought up, or when an operator starts it, and then keeps running indefinitely. It is how services live on z/OS.
The contrast is with a batch job, which is submitted, runs its steps, produces output and ends. A started task has no natural end. CICS regions, DB2, the job entry subsystem, network services and monitoring tools all run this way.
Started tasks are usually defined once by a system programmer and then started and stopped by operators using system commands. Each runs in its own address space and under its own security identity, so its access to datasets and resources can be controlled precisely.
The distinction is simple: if it is always there waiting to serve requests, it is probably a started task; if it was submitted to do a specific piece of work and then finish, it is a job.
Related terms
- Address spaceAn isolated pocket of memory in which a program runs, so that one program cannot interfere with another.
- SubsystemA major piece of software running under z/OS that provides a service to applications, such as a database or a transaction manager.
- JobA unit of batch work submitted to the system, made up of one or more steps that run in order.
- OperatorThe person who watches the running systems, responds to messages, and starts, stops and recovers work.
- CICS regionOne running copy of CICS, with its own programs, files and users. A site typically runs several.