Using a JDBC connection pool to manage database resources used by an integration server

Use integration node JDBC provider resources to configure the use of thread pools independently of message flow and input node thread pools.

About this task

IBM® App Connect Enterprise manages JDBC connections in the following ways:
  • Non-pooled connections:
    • IBM App Connect Enterprise creates a JDBC connection on demand for each message flow instance that requires one.
    • Each JDBC connection is associated with the message flow instance for which it was created. This association is maintained until the connection is closed.
    • Each JDBC connection that is idle for 60 seconds is closed, and is no longer associated with a message flow instance.
    • After a JDBC connection that was associated with a message flow instance is closed, if the same message flow instance requires a JDBC connection, IBM App Connect Enterprise creates a new JDBC connection on demand.
  • Pooled connections:
    • When a message flow instance requires a JDBC connection, IBM App Connect Enterprise assigns an unused connection from the pool.
    • If all pooled JDBC connections are being used, and the maximum pool size has not been reached, IBM App Connect Enterprise creates a new pooled JDBC connection. The maximum pool size is specified in the Maximum size of connection pool property of the JDBC Providers policy (JDBCProviders).
    • Each pooled JDBC connection remains associated with a message flow instance only for the processing of one input message.
    • When a message flow instance completes the processing of an input message, the association with a JDBC connection is removed, and the JDBC connection is returned to the pool.
    • Each pooled JDBC connection that is idle for 15 minutes is closed, and is removed from the pool.
    • Pooled JDBC connections are not applicable to the DatabaseRetrieve and DatabaseRoute nodes.

Using a JDBC connection pool enables you to scale database access independently of the number of message flow threads.

The purpose of the JDBC connection pooling function in IBM App Connect Enterprise is to:
  • Minimize the time and resource needed to create new connections, by making pooled connections available for reuse by other message flow threads when transactions complete.
  • Enable greater control over the number of concurrent database connections that can be in use at any time for a specific JDBC data source.
Although these aims overlap with those of J2EE Java™ connection pooling, the priority is not to maximize the performance of individual JDBC calls to the database. In this respect, non-pooled JDBC connections might be more efficient in some scenarios.

You can create a JDBC connection pool by setting the Maximum size of connection pool property of the JDBC Providers policy to a non-zero integer value. This property acts at the integration server level to specify the maximum number of JDBC connection threads that can be used. A value of zero defaults to the standard WebSphere® Message Broker Version 8.0 behavior, where one JDBC connection is created for each message flow thread.

All message flows within an integration server that use the same JDBC Providers policy also share a connection pool. You can monitor the behavior of a JDBC connection pool by using integration node resource statistics

The Maximum size of connection pool property is applicable to JDBC connections obtained using the getJDBCType4Connection() API of the JavaCompute node, and to database operations in graphical data maps that are called by the Mapping node.

Note: The Maximum size of connection pool property does not apply to the JDBC connections used by the DatabaseRetrieve or DatabaseRoute nodes.