Edit Connection Pool

Use the Edit Connection Pool page to edit the general properties of a JDBC connection pool.

The Edit Connection Pool page contains the following options.

Name

A read-only field identifying the name for the connection pool.

Datasource Classname

The vendor-specific class name that implements the data source.

Resource Type

Choices include javax.sql.XADataSource (global transactions), java.sql.ConnectionPoolDataSource (local transactions, possible performance improvements), and javax.sql.DataSource (local transactions only).

Description

A short description for the connection pool.

Initial and Minimum Pool Size

The minimum number of connections in the pool. This value also determines the number of connections placed in the pool when the pool is first created or when application server starts.

Maximum Pool Size

The maximum number of connections in the pool.

Pool Resize Quantity

When the pool scales up and scales down toward the maximum and minimum pool size respectively, it is resized in batches. This value determines the number of connections in the batch. Making this value too large delays connection creation and recycling; making it too small will be less efficient.

Idle Timeout

The maximum time, in seconds, that a connection can remain idle in the pool. After this time expires, the connection is removed from the pool.

Max Wait Time

The maximum time, in milliseconds, that an application requesting a connection will wait before getting a connection timeout.

Connection Validation

If this option is selected, connection validation is required, allowing the server to reconnect in case of failure.

Validation Method

The application server can validate database connections in three ways: auto-commit, metadata, and table.

Auto-commit and metadata

The application server validates a connection by calling the con.getAutoCommit and con.getMetaData methods.


Note - Many JDBC drivers cache the results of these calls. As a result, using these calls might not always provide reliable validations. Check with the driver vendor to determine whether these calls are cached or not.


Table

The application queries the database table that is specified. The table must exist and be accessible, but no rows are required. Do not use an existing table that has a large number of rows, or a table that is already frequently accessed.

Table Name

Name of the database table for validation.

This field is applicable only if validation method was set to Table in the preceding field.

On Any Failure

If this option is enabled, the application server closes all connections in the pool and re-establishes them when any connection fails. If the option is disabled, individual connections are re-established only when they are used.

Allow Non Component Callers

If this option is enabled, the pool can be used by non-component callers such as servlet filters.

Non Transactional Connections

If this option is enabled, non-transactional connections are returned.

Transaction Isolation

If a transaction isolation level is specified, connections in this pool operate at the specified level. Otherwise, the connections operate with default isolation levels provided by the JDBC driver.

Isolation Level

This field is applicable only if a transaction isolation level was specified in the preceding field.

If the Guaranteed checkbox is selected, all connections taken from the pool have the same isolation level. For example, if the isolation level for the connection is changed programmatically (with con.setTransactionIsolation) when last used, then this mechanism changes the status back to the specified isolation level.

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