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About the Siebel Application Object Manager

Application Object Managers (AOMs) host the Business Objects layer and Data Objects layer of the Siebel architecture. The Web clients host the Siebel application user interface layer. The AOM is used primarily to support Siebel Web client connections. To do this, the AOM handles multiple users simultaneously by making requests to the Siebel Server on their behalf.

AOMs are hosted as components in the Siebel Server and run on the application server (the machine that hosts the Siebel Server). The Siebel Server provides the infrastructure for an AOM to serve multiple Siebel Web client users. Multiple AOM components can run on a single Siebel Server installation. AOM components can be configured to run as multithreaded processes in the Siebel Server. Like other Siebel Server components, you can administer AOM components using the Siebel Server Manager.

AOMs communicate with clients using the TCP/IP protocol through a Web server that contains the Siebel Web Server Extension plug-in (SWSE). Communication between the Web server and the AOM can be compressed and encrypted. An independent session is established to serve incoming connect requests from each client. Subsequent requests from clients are directed to the same AOM tasks until the sessions are terminated. After startup, AOMs do not achieve their full run-time environments until after the first connect, therefore, leading to possible delays during the first connection. For further information on the communication of Web clients and AOMs, see Performance Tuning Guide.

The Siebel repository file (SRF) is installed as part of each Siebel Server installation. Any changes to the repository file must be applied to the appropriate Siebel Server installations that serve the modified application to the Web clients. When they reconnect to an AOM, Web client users automatically retrieve the new Siebel application configuration. User preferences set and saved by Web client users are saved on the Siebel Server.

NOTE:  If you are running the Siebel Server in a UNIX environment, Application Object Managers support eScript, but not Visual Basic.

About AOM Memory Allocation

The Application Object Manager (AOM) caches information in a couple of different ways. Some information is cached and used by every connection and other information is stored for each user connection.

The AOM's memory allocation can be broken into three areas:

• User memory
• Shared memory between users
• Administrative memory used to manage the AOM itself

User Memory

The user area maintains specific information about each user's session. Typically, each user uses 3 MB to 4 MB of memory, although this depends on the Siebel application in use. This memory is released when the task is completed.

Shared Memory

Shared memory is for common structures used by every user and is the largest segment of AOM memory. It contains definitions for business objects, business components, controls, and other metadata items from the Siebel repository, or SRF file. This memory is loaded as needed and remains loaded for the life of the process. AOM processes commonly use more than 150 MB.

Administrative Memory

The administrative area of memory used by AOM manages the component itself. This memory is relatively small and is used to manage communication between the AOM and other Siebel Server components. It runs the listener and coordinates threads and tasks.