Micro Focus Visual COBOL 2.3 for Eclipse (UNIX) > Deployment > Deploying to Enterprise Server > Enterprise Server configuration and administration > Configuring the Server Instance Environment > Using XA-Compliant Resources (XARs)

Using XA-Compliant Resources (XARs)

Restriction: This topic applies only when the Enterprise Server feature is enabled.

In the X/Open XA model, Enterprise Server coordinates all XA activity, serving as an XA Transaction Manager (TM).

Enterprise Server works with XA-compliant Resource Managers (RMs) and manages the execution of:

Container-managed services such as Web services and EJBs

RM access is provided for:

SQL Server
ODBC (generic one-phase commit)
DB2 LUW
Oracle

XA-compliant Resources (XARs)

For Enterprise Server to work properly with an RM, an XAR must be defined. An XAR definition must include:

An xa_open string that includes standard RM fields and values, and optionally, additional Micro Focus-specific fields and values.
An RM switch module
An XAR ID that uniquely identifies the XAR. This ID is used to determine which XAR to use in JES jobs. If compiling with the XAID compiler directive option, the XAR ID is used as the XAID value.

RM switch modules

A Micro Focus RM switch module is COBOL code that obtains the address of the XA switch data structure (xa_switch_t) provided by the RM, typically a database vendor. In addition, Micro Focus RM switch modules contain additional code that facilitates ease of use in Enterprise Server environments. RM switch modules are differentiated by their type, which is determined by the database vendor or other RM type. For example, you use an Oracle RM switch module type with Oracle databases, and so on.

Visual COBOL provides the COBOL source code you need to compile, generating the appropriate switch modules. Once generated, you deploy an RM switch module to Enterprise Server, and then specify it as a part of your XAR definition.

XAR IDs

The XAR ID uniquely identifies your XAR, and is used as the value for the XAID compiler directive option when compiling source code, if required.

For further details the XAID compiler directive option topic for COBSQL, OpenESQL or DB2 ECM.

XARs in Enterprise Server

In Enterprise Server, you can define XARs, and edit and delete XAR definitions. You can also control which XARs are loaded when a specific enterprise server region starts.