Implementing Siebel Business Applications on DB2 for z/OS > Preparing for Implementation on the DB2 Host > Configuring DB2 Connect >

Setting DB2 Connect EE Configuration Options

The DB2 Connect EE product is a server version that allows multiple users to connect to DB2 on the z/OS host. Because it is a server, you must complete additional configuration steps:

• You must specify whether or not to enable connection concentration.

  For information on connection concentration, see About Connection Concentration.

• You must define the maximum number of concurrent users.

  For information on specifying the number of concurrent users allowed, see Setting the MAXAGENTS Parameter Value.

About Connection Concentration

Connection concentration provides additional workload balancing opportunities for DB2 Data Sharing by allowing connections to be rebalanced across DB2 Data Sharing members at the commit phase, instead of only at the time of initial connection. This dynamic rebalancing of connections across members can be beneficial after a planned or unplanned outage to DB2.

NOTE:  Connection concentration is disabled by default during the installation of DB2 Connect.

The default settings for the configuration parameters that control connection concentration are:

• Priority of agents (AGENTPRI) is SYSTEM.
• Maximum number of existing agents (MAXAGENTS) is 100. MAXAGENTS is the maximum number of worker agents. This value represents the maximum number of concurrent connections to DB2 for z/OS.
• Agent pool size (NUM_POOLAGENTS) is 50 (calculated). NUM_POOLAGENTS is the maximum number of idle pool agents. This value represents the number of concurrent connections to DB2 for z/OS. Setting this parameter to 0 disables connection pooling.
• Initial number of agents in pool (NUM_INITAGENTS) is 0.
• Maximum number of coordinating agents (MAX_COORDAGENTS) is equal to (MAXAGENTS minus NUM_INITAGENTS).
• Maximum number of concurrent coordinating agents (MAXCAGENTS) is equal to MAX_COORDAGENTS.
• Maximum number of client connections (MAX_CONNECTIONS) is equal to the value of MAX_COORDAGENTS. When MAX_CONNECTIONS is equal to MAX_COORDAGENTS, Connection Concentration is not enabled.

Enabling Connection Concentration

The following procedure describes how to enable connection concentration.

To enable Connection Concentration

• Set the value of the maximum number of client connections so that MAX_CONNECTIONS is greater than MAX_COORDAGENTS (MAX_CONNECTIONS equals MAX_COORDAGENTS plus 1).

  Setting MAX_CONNECTIONS to equal MAX_COORDAGENTS plus1 enables the Connection Concentration dynamic rebalancing capabilities and still allows the transaction pooling to be handled by Siebel pooling.

  NOTE:  If you enable Connection Concentration, you must first set the value for the maximum number of agents (MAXAGENTS) parameter; this value determines the value of other parameters. Set the value of the MAXAGENTS parameter as appropriate for your site; this value varies according to the memory available and the number of server connections expected.

Setting the MAXAGENTS Parameter Value

If you do not want to enable connection concentration, and if you have not made any adjustments to the connection concentration parameters, then the only configuration to do is to set the number of MAXAGENTS to the number of concurrent connections to DB2 that you expect will be required. To set this number, issue an update dbm cfg using statement. For more information on updating the database manager configuration, see the vendor documentation on the IBM Web site.

If you are using Siebel connection pooling (and it is recommended that you do), the value you choose for MAXAGENTS determines the value you specify for the MaxSharedDbConns parameter value. Further, it determines the value you specify for the MAXDBATS parameter on the z/OS host. For more information about this feature, see Database Connection Pooling.