JDBC Multi Data Sources

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JDBC Multi Data Sources

Column Display Related Tasks Related Topics
A JDBC multi data source is an abstraction around a group of data sources that provides load balancing and failover between data sources. As with data sources, multi data sources are also bound to the JNDI tree. Applications can look up a multi data source on the JNDI tree and then reserve a database connection from a data source. The multi data source determines from which data source to provide the connection.
Use this page to create or view multi data sources in your domain.
Column Display

You can show fewer or additional data points on this page by expanding Customize this table and modifying the Column Display list. Each data point displays in its own table column.
The following table lists all of the data points that you can display in columns on this page.

Name Description

Name of
A unique name that identifies this data source in the WebLogic domain.
MBean Attribute (Does not apply to application modules) :
JDBCDataSourceBean.Name
Changes take effect after you redeploy the module or restart the server.
JNDI Name
The JNDI name of this JDBC multi data source.
MBean Attribute (Does not apply to application modules) :
JDBCDataSourceParamsBean.JNDINames
Changes take effect after you redeploy the module or restart the server.
Algorithm Type
The algorithm determines the connection request processing for the multi data source.
You can specify one of the following algorithm types:

Failover
Connection requests are sent to the first data source in the list; if the request fails, the request is sent to the next data source in the list, and so forth. The process is repeated until a valid connection is obtained, or until the end of the list is reached, in which case an exception is thrown.
Load balancing
The multi data source distributes connection requests evenly to its member data sources. With this algorithm, the multi data source also provides failover processing. That is, if a request fails, the multi data source sends the request to the next data source in the list until a valid connection is obtained, or until the end of the list is reached, in which case an exception is thrown.

MBean Attribute (Does not apply to application modules) :
JDBCDataSourceParamsBean.AlgorithmType
Changes take effect after you redeploy the module or restart the server.
Targets
The servers and clusters to which this multi data source is targeted.
MBean Attribute:
TargetInfoMBean.Targets
Row Prefetch Enabled
Enables multiple rows to be "prefetched" (that is, sent from the server to the client) in one server access.
When an external client accesses a database using JDBC through WebLogic Server, row prefetching improves performance by fetching multiple rows from the server to the client in one server access. WebLogic Server ignores this setting and does not use row prefetching when the client and WebLogic Server are in the same JVM.
MBean Attribute (Does not apply to application modules) :
JDBCDataSourceParamsBean.RowPrefetch
Changes take effect after you redeploy the module or restart the server.
Row Prefetch Size
If row prefetching is enabled, specifies the number of result set rows to prefetch for a client.
The optimal prefetch size depends on the particulars of the query. In general, increasing this number will increase performance, until a particular value is reached. At that point further increases do not result in any significant performance increase. Very rarely will increased performance result from exceeding 100 rows. The default value should be reasonable for most situations.
MBean Attribute (Does not apply to application modules) :
JDBCDataSourceParamsBean.RowPrefetchSize
Minimum value: 2
Maximum value: 65536
Changes take effect after you redeploy the module or restart the server.
Stream Chunk Size
Specifies the data chunk size for steaming data types.
Streaming data types (for example resulting from a call to getBinaryStream()) are sent in sized chunks from WebLogic Server to the client as needed.
MBean Attribute (Does not apply to application modules) : JDBCDataSourceParamsBean.StreamChunkSize
Minimum value: 1
Maximum value: 65536
Changes take effect after you redeploy the module or restart the server.

Related Tasks

Create JDBC multi data sources
Create JDBC data sources
Delete JDBC multi data sources

Related Topics

Configuring and Deploying WebLogic JDBC Resources
JDBC Multi Data Sources

Name	Description
Name of	A unique name that identifies this data source in the WebLogic domain. MBean Attribute (Does not apply to application modules) : `JDBCDataSourceBean.Name` `Changes take effect after you redeploy the module or restart the server.`
JNDI Name	The JNDI name of this JDBC multi data source. MBean Attribute (Does not apply to application modules) : `JDBCDataSourceParamsBean.JNDINames` `Changes take effect after you redeploy the module or restart the server.`
Algorithm Type	The algorithm determines the connection request processing for the multi data source. You can specify one of the following algorithm types: Failover Connection requests are sent to the first data source in the list; if the request fails, the request is sent to the next data source in the list, and so forth. The process is repeated until a valid connection is obtained, or until the end of the list is reached, in which case an exception is thrown. Load balancing The multi data source distributes connection requests evenly to its member data sources. With this algorithm, the multi data source also provides failover processing. That is, if a request fails, the multi data source sends the request to the next data source in the list until a valid connection is obtained, or until the end of the list is reached, in which case an exception is thrown. MBean Attribute (Does not apply to application modules) : `JDBCDataSourceParamsBean.AlgorithmType` `Changes take effect after you redeploy the module or restart the server.`
Targets	The servers and clusters to which this multi data source is targeted. MBean Attribute: `TargetInfoMBean.Targets`
Row Prefetch Enabled	Enables multiple rows to be "prefetched" (that is, sent from the server to the client) in one server access. When an external client accesses a database using JDBC through WebLogic Server, row prefetching improves performance by fetching multiple rows from the server to the client in one server access. WebLogic Server ignores this setting and does not use row prefetching when the client and WebLogic Server are in the same JVM. MBean Attribute (Does not apply to application modules) : `JDBCDataSourceParamsBean.RowPrefetch` `Changes take effect after you redeploy the module or restart the server.`
Row Prefetch Size	If row prefetching is enabled, specifies the number of result set rows to prefetch for a client. The optimal prefetch size depends on the particulars of the query. In general, increasing this number will increase performance, until a particular value is reached. At that point further increases do not result in any significant performance increase. Very rarely will increased performance result from exceeding 100 rows. The default value should be reasonable for most situations. MBean Attribute (Does not apply to application modules) : `JDBCDataSourceParamsBean.RowPrefetchSize` `Minimum value: 2` `Maximum value: 65536` `Changes take effect after you redeploy the module or restart the server.`
Stream Chunk Size	Specifies the data chunk size for steaming data types. Streaming data types (for example resulting from a call to `getBinaryStream()) are sent in sized chunks from WebLogic Server to the client as needed.` `MBean Attribute (Does not apply to application modules) : JDBCDataSourceParamsBean.StreamChunkSize` `Minimum value: 1` `Maximum value: 65536` `Changes take effect after you redeploy the module or restart the server.`