Concurrent Managers

Concurrent processing is at the core of every oracle applications instance. Over the years Oracle Applications has come through a number of changes but concurrent processing has retained itself and in fact got new features added on to its self with very new version.

The request processing on Oracle Applications takes place through the implementation of concurrent Managers. These Managers allow for a concurrent processing of jobs and also scheduling and queuing of jobs.

The objective of the current post is to go through a overview of Concurrent Managers and concurrent processing in Oracle Applications.

The default installation of Oracle Applications comes with a number of pre defined concurrent managers however you can create your custom concurrent managers to spread out the load of your job processing.

Apart from taking care of the load of your jobs the concurrent managers can also be made to schedule periodic jobs and you could also have the concurrent managers run in specific workshifts thus allowing specific programs to be run with specific priority and specific times.

Concurrent managers also allows you to tweak the number of concurrent process that it can handle concurrent if the request exceed this prescribed limt they are automatically put on pending state. The processing of a request takes place based on the time of request submission and priority of the request submitted.

As mentioned there are different types of concurrent mangers in Oracle Applications among them the three important manager which are required by any oracle applications installation are stated below

Internal Concurrent Manager (ICM) - The Internal concurrent manager or the ICM is the 'master' concurrent manager. Its primary responsibility is to take care of the starting and stopping of all other concurrent managers that have been defined in the system and activated. However once the other managers are up and running the ICM does not play much of a role. It is for the same reason that despite your ICM being down oracle applications continues to perform as expected most of the times. That is you would be able to continue submitting requests even with the ICM down. However there are cases where you can evolve your ICM to do larger roles like acting as a conflict resolution manager or in case you have generic service management enabled your ICM can take care of starting and stopping other application services also.

Standard Concurrent Manager - This the core manger and the most hard working of the three. It takes care of managing all the concurrent requests in the system. If however specific programs have been defined to use specific concurrent manager they would be taken care by that manager in all other cases the standard manager will be the default concurrent manager and will process the request. That is by default all the concurrent programs are defined to be run by the standard manager and they should not be excluded unless you have included them to run by an other manager. Though we can change a few setting of the standard concurrent manager like the number of process it can handle, most of the other definition should remain unchanged.

Conflict Resolution Manager (CRM) - The conflict resolution manager of the CRM is responsible of handling any conflicts that might occur within the concurrent programmes. This conflict could be as a result of various reasons for example there might be a business requirement that two instances of a particular report should not be executed at the same time or during a particular period. In case such a scenario occurs the CRM is responsible for taking care of such request. As in the case of the standard concurrent manager the definition for the CRM should be rarely changed.

Apart from these three concurrent manages there is another type of concurrent manager known as the Transaction Manager also exists. The transaction manager is responsible for taking the load off the concurrent request table for pooling the request submitted by the user.The transaction manager takes care of these requests and sends it to standard manager directly.In a RAC environment the Transaction manager is required to be activated on each node of the RAC environment.

From the front end you could view the status of your concurrent manager by logging with the System Administration responsibility and going to the Concurrent Manager administer screen.

The concurrent managers are like other process which run on the oracle applications executable FNDLIBR. The FNDLIBR executable is located at $FND_TOP/bin.

You could also grep the FNDLIBR executable to check if any concurrent manager process are running

$ ps -ef|grep FNDLIBR

The $FND_TOP/sql/afcmstat.sql script gives you a list of concurrent managers and their respective status.

The status of concurrent managers and the nodes on which they are configured can also be known from the Oracle Applications manager.