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
EDB PostgreSQL (early adopter program)
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
An RM switch module
An XAR ID

xa_open string

A string that includes standard RM fields and values, and optionally, additional Micro Focus-specific fields and values.

RM switch module

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 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 build the appropriate switch modules. Once built, you deploy an RM switch module to Enterprise Server, and then include it in an XAR definition.

XAR ID

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.