3.17.2 Overview of connection pool clustering

A connection pool that is clustered is called connection pool clustering. This subsection describes the connection pool clustering configuration and the functionality available with connection pool clustering.

Organization of this subsection
(1) Connection pool clustering configuration
(2) Preconditions
(3) J2EE components and functionality available for database connections
(4) Available resource connection and transaction management functionality

(1) Connection pool clustering configuration

The member resource adapters connected to each database node and the root resource adapter that bundles these multiple member resource adapters together configure a clustered connection pool. A description of the root resource adapter and member resource adapter is as follows:

The following figure shows the flow of processing for obtaining a connection when the connection pool is clustered.

Figure 3-63 Flow of processing for obtaining a connection

[Figure]

  1. The J2EE application makes a connection request to the root resource adapter.
  2. The root resource adapter selects one member connection pool and sends the connection request.
  3. A connection is selected from the member connection pool and returned to the J2EE application.

(2) Preconditions

The database that can use the connection pool clustering functionality is Oracle11g only when the RAC functionality is used. The available JDBC driver is Oracle JDBC Thin Driver.

(3) J2EE components and functionality available for database connections

The following table describes the J2EE components and functionality available for database connections when the connection pool clustering functionality is used.

Table 3-73 J2EE components and functionality available for database connections (Connection pool clustering functionality)

ItemsOracle11g (when the connection pool clustering functionality is used)
J2EE componentsServlet/JSPY
Stateless Session BeanY
Stateful Session BeanY
Singleton Session BeanY
Entity Bean (BMP)Y
Entity Bean (CMP 1.1)N
Entity Bean (CMP 2.0)N
Message-driven BeanN
Available functionalityConnection poolingY
Connection pool warming upY
Displaying the connection pool information (cjlistpool command)Y
Clearing the connection poolY
Connection test for resourcesY
Detecting the connection errorsY
Statement poolingY
Statement cancellationY#
Statement setQueryTimeout methodY#
PRF trace output for the connection IDY
Output of the SQL statement for troubleshootingY
Legend:
Y: Available
N: Not available

# Precautions need to be taken when you connect to Oracle. For details, see 3.6.6 Preconditions and notes on connecting to Oracle.


Note
To use a resource adapter, you must resolve the references from the J2EE application to the resource adapter. When you customize a J2EE application that uses the resource adapters, resolve the references from the J2EE application to the resource adapter.

(4) Available resource connection and transaction management functionality

For details on the functionality available with the root resource adapter and member resource adapter, see 3.3.4 Resource adapter functionality.