JDBC MultiPools

[Attributes and Console Screen Reference for JDBC MultiPools]

A MultiPool is a pool of connection pools. Used in local (non-distributed) transactions, MultiPools aid in either:

• Load Balancing - pools are accessed using a round-robin scheme. When switching connections, WebLogic Server selects a connection from the next connection pool in the order listed.
• High Availability - connection pools are listed in the order that determines the order in which connection pool switching occurs. That is, WebLogic Server provides database connections from the first connection pool on the list. If that connection pool fails, it attempts to use a database connection from the second, and so forth.

Note: MultiPools are not supported for use in distributed transactions. You cannot use connections from a connection pool within a MultiPool if the connection pool uses an XA driver to create database connections.

For more general information about MultiPools, see "Configuring and Using MultiPools in Programming WebLogic JDBC.

 

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Configuring MultiPools

The following sections provide detailed instructions for configuring MultiPools.

 

Creating and Configuring a JDBC MultiPool

1. Click to expand the JDBC node.
2. Click the MultiPools node. The MultiPools table displays in the right pane showing all the MultiPools defined in your domain.
3. Click the Configure a New JDBC MultiPool text link. A dialog displays in the right pane showing the tabs associated with configuring a new MultiPool.
4. On the General tab do the following:
   1. Enter a value in the Name attribute field.
   2. Select one of the following options in the Algorithm Type drop-down list:

      Load Balancing - Select this option if you want to use connections from all connection pools in the MultiPool to balance the load between connection pools and underlying DBMS servers.

      High Availability - Select this option if you want to use all available connections in one pool before using connections in another.

5. Click Create to create a MultiPool instance with the name and attributes you specified on the General tab. The new instance is added under the MultiPools node in the left pane.
6. On the Pools tab do the following:
   1. Select the connection pools from the Pool List in the Available column that you want to assign to the MultiPool.
   2. Click the mover control to move the connection pools you selected to the Chosen column.
7. Click Apply to save your changes.

You must deploy the MultiPool before you can use connections from it. See Deploying a JDBC MultiPool on One or More Servers and Clusters.

 

Cloning a JDBC MultiPool

1. In the left pane, click to expand the JDBC and MultiPool nodes.
2. Right-click the MultiPool you want to clone and select Clone MultiPool name. A dialog displays in the right pane showing the tabs associated with cloning a MultiPool.
3. Enter a value in the Name attribute field and optionally select a value for Algorithm Type.
4. Click Clone to create a MultiPool with the attributes you specified on the General tab and with cloned values on all other tabs. The new MultiPool is added under the MultiPools node in the left pane.
5. Optionally, click the remaining tabs for the MultiPool and change the attribute fields or accept the current values.
6. Click Apply to save any changes you make.

 

Deploying a JDBC MultiPool on One or More Servers and Clusters

1. In the left pane, click to expand the JDBC and MultiPool nodes.
2. Click the MultiPool you want to assign. A dialog displays in the right pane showing the tabs associated with this MultiPool.
3. Click the Target and Deploy tab and select the servers or clusters on which you want to deploy the MultiPool. You should deploy the MultiPool on the same deployment targets that the underlying connection pools are deployed on. Click Apply to save your changes.

When deploying a MultiPool on a cluster, in most cases you should deploy the MultiPool to the entire cluster. You should deploy the related data source and underlying connection pools on the same targets.

 

Adding a Note to a JDBC MultiPool

1. In the left pane, click the JDBC node to expand it.
2. Click the MultiPools node to expand it and show the list of multipools defined in your domain.
3. Click the MultiPool to which you want to add a note. A dialog displays in the right pane showing tabs with attributes for the MultiPool.
4. Click the Notes tab. Type the note in the Notes field.
5. Click Apply to save your changes.

 

Deleting a JDBC MultiPool

1. In the left pane, click to expand the JDBC and MultiPools nodes to display the list of MultiPools in the current domain.
2. Right-click the MultiPool you want to delete and select Delete MultiPool name. A dialog displays in the right pane asking you to confirm your deletion request.
3. Click Yes to delete the MultiPool.