6.4.4.2. Configure XA Recovery Modules

For most JDBC and JMS resources, the recovery module is automatically associated with the resource. In these cases, you only need to configure the options that allow the recovery module to connect to your resource to perform recovery.
For custom resources which are not JDBC or JMS, contact Red Hat Global Support Services for information on supported configurations.
Each of these configuration attributes can be set either during datasource creation, or afterward. You can set them using either the web-based Management Console or the command-line Management CLI. Refer to Section 6.4.1, “Create an XA Datasource with the Management Interfaces” and Section 6.4.2, “Modify an XA Datasource with the Management Interfaces” for general information on configuring XA datasources.
Refer to the following tables for general datasource configuration attributes, and for information about configuration details relating to specific database vendors.

Table 6.2. General Configuration Attributes

Attribute Description
recovery-username
The username the recovery module should use to connect to the resource for recovery.
recovery-password
The password the recovery module should use to connect to the resource for recovery.
recovery-security-domain
The security domain the recovery module should use to connect to the resource for recovery.
recovery-plugin-class-name
If you need to use a custom recovery module, set this attribute to the fully-qualified class name of the module. The module should extend class com.arjuna.ats.jta.recovery.XAResourceRecovery.
recovery-plugin-properties
If you use a custom recovery module which requires properties to be set, set this attribute to the list of comma-separated key=value pairs for the properties.

Vendor-Specific Configuration Information

Oracle
If the Oracle datasource is configured incorrectly, you may see errors like the following in your log output:
WARN  [com.arjuna.ats.jta.logging.loggerI18N] [com.arjuna.ats.internal.jta.recovery.xarecovery1] Local XARecoveryModule.xaRecovery  got XA exception javax.transaction.xa.XAException, XAException.XAER_RMERR
To resolve this error, ensure that the Oracle user configured in recovery-username has access to the tables needed for recovery. The following SQL statement shows the correct grants for Oracle 11g or Oracle 10g R2 instances patched for Oracle bug 5945463.
GRANT SELECT ON sys.dba_pending_transactions TO recovery-username;
GRANT SELECT ON sys.pending_trans$ TO recovery-username;
GRANT SELECT ON sys.dba_2pc_pending TO recovery-username;
GRANT EXECUTE ON sys.dbms_xa TO recovery-username;
If you use an Oracle 11 version prior to 11g, change the final EXECUTE statement to the following:
	GRANT EXECUTE ON sys.dbms_system TO recovery-username;
PostgreSQL
See the PostgreSQL documentation for instructions on enabling prepared (i.e. XA) transactions. Version 8.4-701 of PostgreSQL's JDBC driver has a bug in org.postgresql.xa.PGXAConnection which breaks recovery in certain situations. This is fixed in newer versions.
MySQL
Based on http://bugs.mysql.com/bug.php?id=12161, XA transaction recovery did not work in some versions of MySQL 5. This is addressed in MySQL 6.1. Refer to the bug URL or to the MySQL documentation for more information.
IBM DB2
IBM DB2 expects method XAResource.recover to be called only during the designated resynchronization stage which occurs when the application server is restarted after a crash or failure. This is a design decision in the DB2 implementation, and out of the scope of this documentation.
Sybase
Sybase expects XA transactions to be enabled on the database. Without correct database configuration, XA transactions will not work. enable xact coordination enables or disables Adaptive Server transaction coordination services. When this parameter is enabled, Adaptive Server ensures that updates to remote Adaptive Server data commit or roll back with the original transaction. To enable transaction coordination, use:
sp_configure 'enable xact coordination', 1
.