An SAP application server has to process SAP requests from multiple front ends. The application server has the use of a dispatcher, which gathers the requests and transfers them for processing to the work processes. The work processes then execute the desired requests (for example, an ABAP program).
Here are the following types of work processes:
Work Process Type |
Use |
Dialog |
Executes dialog programs (ABAP) |
Update |
Asynchronous database changes (is controlled by a COMMIT WORK statement in a dialog work process) |
Background |
Executes time-dependent or event-controlled background jobs |
Enqueue |
Executes locking operations (if SAP transactions have to synchronize themselves) |
Spool |
Print formatting (to printer, file or database) |
Several dialog work processes usually run on one application server. There are usually only one or two other types of work processes. For more information, see Setting Up Work Process Distribution in the CCMS Documentation.
A work process consists of a screen processor, the ABAP interpreter, the database interface and the task handler that calls these programs.
The dispatcher is the central process of the application server. After it has been started, it generates the work process. You can configure the number of different types of work processes that run on an application server (see Setting Up Work Process Distribution).
See also:
Virtual Address Space of a Work Process