Create connections from each broker to its database using ODBC.
Broker components and execution groups read and write data about internal operations to a broker database. The number of connections needed depends on the actions of the message flows that the broker processes. Each broker needs the following connections:
If you are using the same database for several brokers, include all brokers in your calculations.
When you start a broker, it opens all connections that it needs to the broker database for its own operation. When you stop the broker, it releases all current database connection handles.
If you are using DB2® for your database, the default action taken by DB2 is to limit the number of concurrent connections to a database to the value of the maxappls configuration parameter. The default for maxappls is 40. Increase this parameter and the associated parameter maxagents to new values based on your calculations, if appropriate.
On all platforms except HP-UX on Itanium, parts of the broker need 32-bit access to the data source. You must therefore always define a 32-bit ODBC data source name (DSN) for the broker to connect to the broker database; this is true even if the broker has a 64-bit database, in which case you must present the broker with an environment that provides a 32 bit-compatible interface to the database (see Setting your environment to support access to databases). On HP-UX on Itanium, the broker is a 64-bit application, therefore you must always define a 64-bit ODBC DSN for the broker to connect to the broker database.
Execution groups on a broker must also be able to connect to the broker database. A 32-bit execution group on a 32-bit broker can connect to the broker database using the same 32-bit DSN definition that the broker uses. A 64-bit execution group on a 32-bit broker, however, needs a 64-bit ODBC connection to be able to connect to the broker database, therefore you must define a 64-bit ODBC DSN for the broker database in addition to the broker's 32-bit DSN definition.
On HP-UX on Itanium, the 64-bit broker supports only 64-bit execution groups, therefore the execution group can access the broker database using the same 64-bit DSN definition that the broker uses; a 32-bit DSN definition is not required.
For help when you are deciding whether to create 32-bit DSNs, 64-bit DSNs, or both, for your broker database, see Enabling ODBC connections to the databases.