MX 2.x)

Guidelines for Implementing an Application Server to Use Connection Pooling

The application server maintains a cache of the PooledConnection objects created by using

ConnectionPoolDataSource interface. When the client requests a connection object, the application looks for

the suitable PooledConnection object. The lookup criteria and other methods are specific to the application

server.

The application server implements the ConnectionEventListener interface and registers the listener object with

the PooledConnection object. The JDBC/MX driver notifies the listener object with a connectionClosed event

when the application is finished using the Connection object. Then, the connection pooling component can reuse

this PooledConnection object for future requests. The JDBC/MX driver also notifies the listener object with

connectionErrorOccurred event when the PooledConnection object fails to initialize the connection. The

application server's connection pooling component should discard the PooledConnection when such a

connection error event occurs.

The application server manages the connection pool by using the SQLMXConnectionPoolDataSource, which

implements the ConnectionPoolDataSource interface. Use the getter and setter methods, provided by

JDBC/MX, to set the connection pool configuration properties listed in the table of Standard

ConnectionPoolDataSource Object Properties. In addition to these standard properties, the

ConnectionPoolDataSource includes the JDBC/MX driver-specific properties as described under Connection

Using the DataSource Interface.

Standard ConnectionPoolDataSource Object Properties

Note: The application server defines the meaning of these properties.

Property Name Type Description

maxStatements int

The total number of PreparedStatement objects that the pool should

cache. This total includes both free objects and objects in use. 0 (zero)

disables statement pooling.

initialPoolSize int

The number of physical connections the pool should contain when it is

created.

minPoolSize int

The number of physical connections the pool should keep available at

all times. 0 (zero) indicates no maximum size.

maxPoolSize int

The maximum number of physical connections that the pool should

contain. 0 (zero) indicates no maximum size.

maxIdleTime int

The number of seconds that a physical connection should remain

unused in the pool before the connection is closed. 0 (zero) indicates

no limit.

propertyCycle int

The interval, in seconds, that the pool should wait before enforcing the

current policy defined by the values of the above connection pool

properties.

Connection Pooling Using the Basic DataSource API