Micro Focus Studio Enterprise Edition for Windows > Deployment > Configuration and Administration > Enterprise Server Configuration and Administration > Configuring the Server Instance Environment > Using XA-Compliant Resources > XA Switch Modules

XA Switch Modules

Note: Source code for XA switch modules is not installed with Server Enterprise Edition or Studio Enterprise Edition Test Server.

Studio Enterprise Edition includes the source code for switch modules for Oracle, IBM DB2, XDB, SQL Server, a generic one-phase ODBC switch module, a two-phase MQSeries switch module, and the additional switch modules for using with JES-initiated transactions in the %ProgramFiles(x86)%\Micro Focus\Studio Enterprise Edition x.x\base\source\enterpriseserver\xa directory.

With the exception of the two-phase MQSeries switch module, you must build each switch module in your development environment, and then copy it to your deployment server. The files are:

ESORAXA.CBL	Oracle
ESDB2XA.CBL	IBM DB2
ESMSSQL.CBL	SQL Server
ESODBCXA.CBL	Generic one-phase commit for ODBC
ESMQXA.DLL	MQSeries¹
ESORAOPC.pco	JES-initiated transactions connecting to Oracle data sources
ESDB2OPC.CBL	JES-initiated transactions connecting to IBM DB2 data sources
ESXDBXA.CBL	XDB
ESXDBOPC.CBL	JES-initiated transactions connecting to XDB Server
¹ The MQSeries module provided is a built module, not a source code file. It is available in both your development and deployment environments. For more information, see The MQSeries XA Switch later in this topic.

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

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.

To build a switch module

As well as the switch module sources, the directory contains the build.bat batch file that you can use to build the switch module you need.

For 32-bit applications:
1. Open a Net Express command prompt, 32-bit.
2. Change to the %ProgramFiles(x86)%\Micro Focus\Studio Enterprise Edition x.x\Base\SOURCE\ENTERPRISESERVER\XA directory (default location).
3. Enter build switch-module
For 64-bit applications:
1. Open a Net Express command prompt, 64-bit.
2. Change to the %ProgramFiles(x86)%\Micro Focus\Studio Enterprise Edition x.x\Base\SOURCE\ENTERPRISESERVER\XA directory (default location).
3. Enter build switch-module

where switch-module is the type of module you want to build, as follows:

Value of `switch-module`	Module type
ora10	Oracle 10 databases
ora11	Oracle 11 databases
db2	IBM DB2 Important: Before building this switch module, ensure your LIB environment variable contains the path to your DB2 LIB directory.
odbc	Generic one-phase commit for ODBC
xdb	XDB

You must also build these additional modules if you need to connect to resources from JES-initiated tasks over IKJEFT01. These modules must be loaded by the main switch module; therefore include the full path to any additional switch modules in your system's PATH environment variable:

Value of `switch-module`	Module type
ora1pc	Oracle databases
db21pc `db2_database_alias` [`db2_userid db2_password`	IBM DB2. Parameters: db2_database_alias The database alias cataloged to the DB2 client on the machine where Enterprise Server is running db2_userid db2_password The user ID and password for connecting to DB2; required only if different from the user ID and password for the user currently logged in
odbc	Generic one-phase commit for ODBC¹
xdb1pc	XDB

Important: If you are running Server Enterprise Edition, build the required switch module in Studio Enterprise Edition, and make it available for use with the standalone Server Enterprise Edition.

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.