Overview of Concurrent Processing In Oracle

Overview of Concurrent Processing

This section explains how a request to run a concurrent program is handled by Oracle Applications, and what the life cycle of a concurrent request is.
In Oracle Applications, concurrent processing simultaneously executes programs running in the background with online operations. As System Administrator, you can manage when programs are run and how many operating system processes Oracle Applications devotes to running programs in the background.

Concurrent Requests, Programs, and Processes

When a user runs a report, a request to run the report is generated. The command to run the report is a concurrent request. The program that generates the report is a concurrent program. Concurrent programs are started by a concurrent manager.
Figure 1 - 11.

Concurrent Managers start concurrent programs

Every time your users request a concurrent program to be run, their request is inserted into a database table, and is uniquely identified by a request ID. Concurrent managers read requests from this table.
Part of a manager's definition is how many operating system processes it can devote to running requests. This number is referred to as the manager's number of target processes.

Running concurrent programs

A concurrent program actually starts running based on:

• When it is scheduled to start

• Whether it is placed on hold,

• Whether it is incompatible (cannot run) with other programs

• Its request priority

Concurrent Request Priorities

The priority of a concurrent request is determined by application username, and is set by the System Administrator using the Concurrent:Priority user profile option.
The first available concurrent manager compares the request's priority to other requests it is eligible to process, and runs the request with the highest priority.
When choosing between requests of equal priority, the concurrent manager runs the oldest request first.

Parent requests and Child requests

Often, several programs may be grouped together, as in a request set. Submitting the request set as a whole generates a request ID, and as each member of the set is submitted it receives its own request ID. The set's request ID identifies the Parent request, and each of the individual programs' request ID identifies a Child request.