Session Pool Options

The following options are displayed in the Session Pools panel and in the panel for each individual session pool:

Session Pool Name — Specifies the name of the pool. When you create a new session pool, it is assigned the name SessionPoolName. Typically, the session pool name and the model name are the same.

Count — Specifies the number of sessions that are preloaded by the server. This is the "low water mark" for the number of sessions that a server should preconnect.

The session count cannot exceed the server's global setting Maximum concurrent sessions or your licensed session limit, which is displayed as the maximum value for this option. If the session pool uses a model variable list, plan for enough model variable list entries for the expected (or maximum) number of concurrent sessions. Otherwise, when all entries are used, any attempt by an additional client to connect to the session pool will result in an exception.

You can control how quickly the sessions are preloaded. The server property setting for Create pooled sessions concurrently is enabled by default. Disable the setting to force serial creation (rather than concurrent creation) of the number of sessions specified here.

Note: Whenever possible, you should set Count to a number equal to the expected number of concurrent sessions. Doing so will provide you with the best server performance.

Max Number of Sessions — Specifies the maximum number of concurrent sessions that can be active in this pool. This is the "high water mark" for the number of sessions that can be created. The value you specify for this option can exceed the session pool's count but it cannot exceed the server's global setting Maximum concurrent sessions, or your licensed session limit. If the session pool has the maximum number of clients connected, any additional runtime client connection request will result in an exception. You can configure the server to automatically notify an administrator when this situation arises by using email configuration or SNMP configuration.

Setting Max Number of Sessions to a number higher than Count allows additional sessions to be loaded and activated after the preloaded sessions are all activated and in use. For example, if Count is set to 100 and Max Number of Sessions is set to 125, the first 100 clients that connect will use preloaded sessions. If an additional client attempts to connect, a session will be loaded and activated for the connection. When it is released, the session will be terminated instead of being placed in the idle pool.

Model Name — Specifies the model used for sessions in the pool. This is the model name that was selected when the session pool was created. In most cases you will not need to change the model name. If you do change it, however, you will also need to select a new startup entity.
Note: When you change the Model Name, the Startup Entity list does not immediately refresh. To refresh the list, click Submit after you change the Model Name. A message will appear warning you that the current startup entity is no longer valid; click OK to dismiss the message. At this point, the Startup Entity list has been refreshed and you can select a new startup entity.

Startup Entity — Specifies the entity the host session will be initialized to when a Data Object attaches to the host session. If the host session is returned to the pool when the Data Object releases it, it will automatically return to this entity for the next Data Object.

Host Name — Specifies the host the sessions in the pool connect to. The name specified here overrides the name stored in the model.

Host Port ID — Specifies the host port ID that the sessions in the pool connect to. The port ID specified here overrides the port ID stored in the model.

Model Debug Messages Recording — Specifies the model debug reporting status for the model. Options include Record Nothing, Record Errors, and Record Everything. Use the Design Tool Model Debug Messages feature to troubleshoot and debug your model. Configure recording options on the Server Properties page of the Administrative WebStation.

Model Variable Options

The following model variable options are listed under the session pool name:

See Working with Model Variables for more information about these options.