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Configuring SISNAPI Connection Pooling for AOM

This section provides information about how to manage SISNAPI connections for your Siebel Server.

SISNAPI (Siebel Internet Session application programming interface), a messaging format that runs on top of the TCP/IP protocol, is used for network communication between AOM and Siebel Web Server Extension (SWSE), installed on the Web server. SISNAPI connections can be configured to use encryption and authentication based on Secure Sockets Layer (SSL).

Each multithreaded process for an AOM component uses a pool of SISNAPI connections managed by the SWSE. The process multiplexes (shares) many client sessions over each connection.

Each client session request opens a new connection and adds it to the pool, until the number of connections defined by the value of the parameter SessPerSisnConn have been created. Subsequent requests are then multiplexed over the existing pooled connections. SISNAPI connections persist until one of the following events occur:

  • Web server process terminates
  • AOM component terminates
  • Value of the parameter SISNAPI Connection Maximum Idle Time (alias ConnIdleTime) is reached

    For more information on this parameter, see Siebel System Administration Guide.

  • Your firewall times out the connection

Multiplexing traffic over a set of SISNAPI connections helps to reduce the number of open network connections.

The SISNAPI connection pool size per multithreaded process for an AOM is determined by the combined settings of MaxTasks, MaxMTServers, and SessPerSisnConn.

SessPerSisnConn determines how many sessions can be multiplexed over a single SISNAPI connection. By default, SessPerSisnConn is set to 20 for AOM components. This figure is suitable for most deployments and generally does not need to be changed. You may set this differently, depending on how you have calculated think time. For details, see Performance Factors for AOM Deployments.

For more information about configuring MaxTasks and MaxMTServers, see Tuning AOM Components for CPU and Memory Utilization.

The number of actual SISNAPI connections per multithreaded process for the AOM is determined by the following formula:

(MaxTasks/MaxMTServers)/SessPerSisnConn = SISNAPI_conn_per_process

where SISNAPI_conn_per_process represents the number of SISNAPI connections per multithreaded process.

Assume, for example, the following parameter values:

MaxTasks = 600

MaxMTServers = 5

SessPerSisnConn = 20

In this case, the formula would be:

(600/5)/20 = 120/20 = 6

Or, if MaxTasks = 540 and SessPerSisnConn is set to 18, the formula would be:

(540/5)/18 = 108/18 = 6

In each case, six SISNAPI connections will be created and pooled for each AOM multithreaded process, from each SWSE. Each Web server and SWSE may potentially have its own set of six connections, so the maximum total number of connections into an AOM process is six times the number of Web servers. In the first example above, 20 sessions would be multiplexed over each connection. In the second example, 18 would be multiplexed over each connection.

NOTE:  In general, it is recommended that the figures used for the above formula be tailored to produce an end result that is an integer. To achieve this, you may need to modify how you define MaxTasks, MaxMTServers, and SessPerSisnConn.

Some Object Manager components are not AOM components. Configuration issues for such components may differ from that applicable to AOM components. For information about the EAI Object Manager, see Tuning Siebel EAI for Performance.

Performance Tuning Guide