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XA Switch Modules

Note: Source code for XA switch modules is not installed with Server Enterprise Edition or Studio Enterprise Edition Test Server.
SQL Server Requirements
The SQL Server module provides two-phase commit support utilizing the Microsoft Distributed Transaction Server (MS DTC), and ensures that any database connections made using this switch module all participate in a single XA transaction. MSDTC must be running on both the client machine, and also the machine(s) where SQL Server is hosted.
SQL Server and ODBC Requirements
Some OpenESQL directives are process-based, and typically need to be set in within the code of the program that makes the database connection. If you are executing services under Enterprise Server that are deployed as container-managed applications, or if you are invoking JES-initiated transactions using IKJEFT01, these directives must be specified when compiling the XA switch module, rather then when compiling your program source.
ODBC Limitations
The ODBC module supports only a one-phase commit, and hence:
  • Cannot be used in conjunction with other resource managers that use this module because, within a given region, the generic ODBC one-phase commit module supports only one active Resource Manager at a time.
  • Can only be used for a single database connection; multiple data source connections are not supported
SQL Server and Generic One-phase Commit for ODBC Limitations
When using the SQL Server and Generic one-phase commit for ODBC switch modules, the following SQL operations are not supported in the source for your deployed container-managed service:
  • CONNECT
  • DISCONNECT
  • BEGIN TRANSACTION
  • COMMIT
  • ROLLBACK
ODBC Requirements
Some OpenESQL directives are process-based, and typically need to be set in within the code of the program that makes the database connection. If you are executing services under Enterprise Server that are deployed as container-managed applications, or if you are invoking JES-initiated transactions using IKJEFT01, these directives must be specified when compiling the XA switch module, rather then when compiling your program source.
ODBC Limitations
The ODBC module supports only a one-phase commit, and hence:
  • Cannot be used in conjunction with other resource managers that use this module because, within a given region, the generic ODBC one-phase commit module supports only one active Resource Manager at a time.
  • Can only be used for a single database connection; multiple data source connections are not supported
Additional Oracle Resources
For more information on using the Oracle XA switch module, including the Open String definition and details of supported SQL operations, see the following:
  • The Database Access Support topic for Third-party Software in the Start Here section of this documentation.
  • The Developing Applications with Oracle XA help topic available in the Oracle RDBMS documentation.
Additional IBM DB2 Resources
For more information on using the IBM DB2 XA switch module, including the Open String definition and details of supported SQL operations, see the following:
  • The Database Access Support topic for Third-party Software in the Start Here section of this documentation.
  • The Transaction Managers help topic available in the IBM RDBMS documentation.
  • DB2 9.1 - The X/Open XA Interface programming considerations help topic available in the IBM RDBMS documentation.

The MQSeries XA Switch

The ESMQXA module is provided as part of the product and does not need to be built. The filename for the built module is esmqxa.dll.

By default, the ESMQXA module operates in two-phase commit mode. You can set the environment variable ES_MQ_1PC to Yes or True in order for the module to operate in one-phase commit mode, but you should only do this if advised to by Micro Focus.

Important: Set the MQ Connection in one of these two places:
  • XA Resource Manager
  • System Initialization Table (SIT)
Do not set it in both. Doing so results in two connections between the Server Enterprise Edition region and the MQ Queue Manager. Only one is required.
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