VX/DMQ - OpenVMS DMQ (PAMS) for x86 Linux

Overview

VX/DMQ provides a call-compatible Asynchronous API set for VMS / OpenVMS applications, implemented on top of Oracle MQ. Since Oracle MQ evolved from DMQ, the functionality and calls are similar, with some modifications for Linux and Windows environments.

Key Features

• Full compatibility with OpenVMS DMQ (PAMS) API set.

• Implemented on top of Oracle MQ, ensuring reliability and scalability.

• VX/RT Asynchronous Backplane wraps Synchronous Oracle MQ to provide a complete DMQ Asynchronous API set.

• Enhanced support for Linux and Windows – allows monitoring of completion without ASTs (since ASTs are not natively supported in Oracle MQ on these platforms).

• Seamless migration path for OpenVMS applications that use DMQ / PAMS messaging.

VX/DMQ API Enhancements

• AST Replacement Mechanism: Since Linux and Windows versions do not generate ASTs, Sector7 has added extra API calls to monitor message completion without ASTs.

• Improved Asynchronous Messaging: VX/DMQ wraps Synchronous Oracle MQ inside VX/RT’s Asynchronous Backplane, allowing full event-driven messaging.

• Enhanced Performance: Optimized for low-latency inter-process communication (IPC) on Linux and Windows.

How VX/DMQ Works

1. Intercepts and translates DMQ / PAMS calls to Oracle MQ functions.

2. Provides asynchronous message queuing and handling, mimicking OpenVMS behavior.

3. Handles message persistence, priority queuing, and reliable delivery.

4. Uses VX/RT for event-driven processing, ensuring minimal latency.

Use Cases

• Migrating DMQ-based applications from VMS / OpenVMS to Linux/Windows.

• Replacing legacy DMQ messaging with modern Oracle MQ solutions while maintaining compatibility.

• High-performance messaging in multi-platform environments.

• Reducing migration complexity by retaining DMQ-style API calls.