Implementing Siebel Business Applications on DB2 UDB for z/OS > Preparing for Implementation on the DB2 Host > Additional Postinstallation Steps for DB2 Connect >

Configuring DB2 Connect for DB2 Connect Enterprise Edition Only

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

  • You must define the maximum number of concurrent users (MAXAGENTS).
  • You must specify whether or not to enable 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 just 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.

Connection Concentration Configuration Parameters

As installed, the default settings for the configuration parameters that control connection concentration are:

  • Priority of agents (AGENTPRI) = SYSTEM
  • Maximum number of existing agents (MAXAGENTS) = 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) = 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) = 0
  • Maximum number of coordinating agents (MAX_COORDAGENTS) = (MAXAGENTS - NUM_INITAGENTS)
  • Maximum number of concurrent coordinating agents (MAXCAGENTS) = MAX_COORDAGENTS
  • Maximum number of client connections (MAX_CONNECTIONS) = MAX_COORDAGENTS

    NOTE:  When MAX_CONNECTIONS = MAX_COORDAGENTS, Connection Concentration is not enabled.

If you do not want to enable Connection Concentration and if you have not made any adjustments to the parameters, then the only configuration to do is to set the number of MAXAGENTS to the number of concurrent users that you expect on the system. 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 value. Further, it determines the value you specify for MAXDBATS on the z/OS. For more information about this feature, see Database Connection Pooling.

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 = MAX_COORDAGENTS +1).

    Setting MAX_CONNECTIONS = MAX_COORDAGENTS +1 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.

Implementing Siebel Business Applications on DB2 UDB for z/OS