Database Reference
In-Depth Information
• SM50 transaction lists work processes of an individual application server.
• SM66 transaction lists active work processes of all the application servers that belong
to one SAP system.
By design, there are limited dialog work processes providing services to several hundred
end users. If a long-running interactive ABAP program is executed, then this has the poten-
tial of tying up all the available dialog work processes, causing the system to hang. In order
to prevent this from happening, SAP delivers a profile parameter rdisp/max_wprun_time
that controls the maximum runtime of the dialog work process. The default value of the
parameter is 600 seconds. The value can be increased to 1,200 seconds for an Online Trans-
action Processing System (OLTP) such as SAP ERP and 3,600 seconds for an Online Ana-
lytical Processing System (OLAP) such as SAP BW. In certain instances where only one
long-running ABAP program is being executed, the parameter can be temporarily disabled
by setting the value to 0. Since this a dynamically switchable parameter, it does not require a
system restart. Because of the previously mentioned reasons, it is always recommended to
run the long-running programs in the background and the background work processes,
which are not restricted by any time limit.
Batch Work Processes
The background (batch) work process is responsible for executing background jobs in the
SAP system. Background job processing is used for noninteractive processing. This is a col-
lection of one or more ABAP or external programs ordered to run serially without any user
intervention. Background work is usually very resource-intensive and long-running, and is
scheduled usually after-hours (night) when there is expected high data volume for database
updates and deletes. Background work processes provide scheduled job services to the
users. The number of background work processes on a given application server is controlled
by the rdisp/wp_no_btc parameter value entered in the instance profile.
Figure 14-5
shows
the SM50 transaction view with background work processes highlighted.
