WebSphere Application Server data source properties

Use this page to set advanced data source properties in the application server. These properties activate and configure services that the application server applies to data sources to customize connections within an application server. These properties do not affect connections within the database.

To access this administrative console page complete one of the following paths:

Statement cache size

Specifies the number of statements that can be cached per connection. The application server caches a statement after you close that statement.

The WebSphere® Application Server data source optimizes the processing of prepared statements and callable statements by caching those statements that are not used in an active connection. Both statement types help maximize the performance of transactions between your application and datastore.

If the statement cache is not large enough, useful entries are discarded to make room for new entries. To determine the highest value for your cache size to avoid any cache discards, add the number of uniquely prepared statements and callable statements (as determined by the SQL string, concurrency, and the scroll type) for each application that uses this data source on a particular server. This value is the maximum number of possible statements that can be cached on a given connection over the life of the server. Setting the cache size to this value means you never have cache discards. In general, configure a larger cache for applications with a greater number of statements.

You can also use the Tivoli® Performance Viewer to minimize cache discards. Use a standard workload that represents a typical number of incoming client requests, use a fixed number of iterations, and use a standard set of configuration settings.
Note: The higher the statement cache, the more system resources are delayed. Therefore, if you set the number too high, then you might lack resources because your system cannot open multiple prepared statements.

If there is a particular statement that you do not want the application server to cache, configure the statement's poolability hint to false. The application server does not cache a statement if the poolability hint is set to false. The application specifies the statement poolability hints at run time.

In test applications, tuning the statement cache improves throughput from 10% to 20%. However, because of potential resource limitations, this might not always be possible.

Data type Integer
Default Default values depend on the database. Typically, this value is 10. For Informix® versions 7.3, 9.2, 9.3, and 9.4, without the respective latest fixes, the default value must be 0. A default value of 0 means that there is no cache statement.

Enable multithreaded access detection

When you check this option, the application server detects the existence of access by multiple threads.

Enable database reauthentication

Indicates that the exact match on connections retrieved out of the application server's connection pool (the connection pool search criteria does not include a user name and password) cannot exist. Instead, the connection re-authentication is done in the doConnectionSetupPerTransaction() of the DataStoreHelper class. The application server does not provide a connection re-authentication implementation at run time. Therefore, when you check this box, you must extend the DataStoreHelper class to provide implementation of the doConnectionSetupPerTransaction() method where the re-authentication occurs. If you do not complete this process, the application server might return unusable connections. For more information, refer to the API documentation for the com.ibm.websphere.rsadapter.DataStoreHelper#doConnectionSetupPerTransaction method.

Connection re-authentication can help improve performance by reducing the overhead of opening and closing connections, particularly for applications that frequently request connections with different user names and passwords.
Avoid trouble: You cannot enable database re-authentication if you select TrustedConnectionMapping for the mapping configuration alias.gotcha

Enable JMS one-phase optimization support

When you check this option, the application server allows Java™ messaging service (JMS) to get optimized connections from this data source. This property prevents Java database connectivity (JDBC) applications from sharing connections with container-managed persistence (CMP) applications.

Manage cached handles

Specifies whether the container tracks cached handles, which are connection handles that an application component holds active across transaction and method boundaries. You can use this property to debug connection problems, but tracking handles can cause large performance overhead during run time.

If the Manage cached handles property is selected in the administrative console, and you deselect it, the field will no longer be visible for resources that are at Version 7.0 of the application server. This field is only displayed if the manageCachedHandles property is set to true in the resources.xml file. To make the field available, change the value for the manageCachedHandles entry from false to true in the resources.xml file, or enter the following Jython command from the wsadmin tool:
AdminConfig.modify(myDataSourceVariable, '[[manageCachedHandles "true"]]')
Supported configurations: For any resources that are running at Version 6.x of the application server, the Manage cached handles property is always be visible. For example, if you have a node that is at Version 6.1, the entry in the resources.xml file does not affect how the field is displayed in the administrative console.sptcfg
For an alternative method of debugging problems, use the multi-thread and cross-component diagnostic alerts to detect violations in the Java Connectivity Architecture (JCA) programming model. To enable these alerts, select those options from Servers > Application servers > application_server > Performance > Performance and Diagnostic Advisor Configuration > Performance and Diagnostic Advice configuration panel. These alerts force the connection manager to manage cached handles, detect the connection conditions, and send alerts.
Note: For these alerts to be active you must also select Enable Performance and Diagnostic Advisor Framework (Runtime Performance Advisor) from the Servers > Application servers > application_server > Performance > Performance and Diagnostic Advisor Configuration panel.

Log missing transaction context

Specifies whether the container issues an entry to the activity log when an application obtains a connection without a transaction context. These are exceptions to the Java Platform, Enterprise Edition (Java EE) programming model connection requirements.

Non-transactional data source

Specifies that the application server does not enlist the connections from this data source in global or local transactions. Applications must explicitly call setAutoCommit(false) on the connection if they want to start a local transaction on the connection, and they must commit or rollback the transaction that they started.

Use WebSphere Application Server exception checking model

Specifies that the application server uses the error mapping facility that is defined in the data store helper to identify errors. The application server does not replace exceptions that are thrown by the JDBC driver with exceptions that are defined in the error map of the data store helper.

Use WebSphere Application Server exception mapping model

Specifies that the application server uses the error mapping facility that is defined in the data store helper to identify errors, and the application server will replace the exceptions that are thrown by the JDBC driver with exceptions that are defined in the error map of the data store helper.

Supported configurations: This error detection model functions with JDBC Version 3.0 and earlier.sptcfg

Validate new connections

Specifies whether the connection manager tests newly created connections to the database.

Number of retries

Specifies the number of times you want to retry making the initial connection to a database after the first pretest operation fails.

Retry interval

If you select Validate new connections, this option specifies the length of time, in seconds, that the application server waits before retrying to make a connection if the initial attempt fails.

Validate existing pooled connections

Specifies whether the connection manager tests the validity of pooled connections before returning them to applications.

Retry interval

If you select Pretest existing pooled connections, this option specifies the length of time, in seconds, to allot to the JDBC driver for validating a connection.

Validation by JDBC driver

Specifies that the application server will use the JDBC driver to validate the connections. The JDBC provider must support JDBC 4.0 or greater to use this option.

Avoid trouble: For an Oracle datasource, Validation by JDBC Driver appears on the administrative console only after the validateNewConnectionTimeout property is added to the custom properties of WebSphere Application Server datasource properties. The validateNewConnectionTimeout property is used for JDBC 4.0 driver validation and can be specified using administrative console.gotcha

Timeout

Specifies the timeout in seconds for testing connections (either new or pooled by the application server) to the database. If the timeout expires before validating then the connection is considered unusable. If retries are configured, the full value of the timeout applies to each retry. A value of 0 indicates the JDBC driver does not impose a timeout on validation attempts.
Supported configurations: This option is only available for JDBC drivers that are JDBC 4.0 compliant.sptcfg

Validation by SQL string (deprecated)

Specifies an SQL statement that the application server sends to the database to test the connection. Use a query that is likely to have low impact on performance.

Optimize for get/use/close/connection pattern with heterogenous pooling

Specifies that the application server will use the get/use/close/connection pattern. This allows connection pooling for the application server to share connections that are in the same transaction. This optimization pattern allows one connection to be shared during a transaction even when connections use different connection properties.

The heterogeneous pooling feature allows you to extend the data source definition so that you can specify different custom properties or allow applications to override non-core properties for the data source.

Supported configurations: This field is only available for DB2® data sources.sptcfg

Retry interval for client reroute

Specifies the amount of time, in seconds, between retries for automatic client reroute.

Supported configurations: This field is only available for DB2 data sources.sptcfg

Maximum retries for client reroute

Specifies the maximum number of connection retries that are attempted by the automatic client reroute function if the primary connection to the server fails. The property is only used when Retry interval for client reroute is set.

Supported configurations: This field is only available for DB2 data sources.sptcfg

Alternate server names

Specifies the list of alternate server name or names for the DB2 server. If more than one alternate server name is specified, the names must be separated by commas. For example:
host1,host2
Supported configurations: This field is only available for DB2 data sources.sptcfg

Alternate port numbers

Specifies the list of alternate server port or ports for the DB2 server. If more than one alternate server port is specified, the ports must be separated by commas. For example:
5000,50001
Supported configurations: This field is only available for DB2 data sources.sptcfg

Client reroute server list JNDI name

Specifies the JNDI name that is used to bind the DB2 client reroute server list into the JNDI name space. The DB2 database server will use this name to look up the alternate server name list when the alternate server information is not already in memory. This option is not supported for type 2 data sources.

Supported configurations: This field is only available for DB2 data sources.sptcfg

Unbind client reroute list from JNDI

Used with test connection only. When set to true, the Client reroute server list JNDI name will be unbound from the JNDI name space after a test connection is issued.

Supported configurations: This field is only available for DB2 data sources.sptcfg



Related concepts
Relational resource adapters and JCA
JDBC providers
Data sources
Related tasks
Configuring a data source using the administrative console
Configuring connection factories for resource adapters within applications
Extend DB2 data source definitions at the application level
Configuring Java EE Connector connection factories in the administrative console
Related reference
Custom property settings
Advice configuration settings
Reference topic    

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Last updated: Oct 20, 2010 7:53:43 PM CDT
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