Introduction to the Listener for IBM MQ

The EntireX Listener for IBM® MQ runs as a listener on an IBM MQ queue and passes messages to an RPC server. It is used to send messages received from an IBM MQ queue to an RPC server application. This means that existing RPC servers can be used for communication with IBM MQ. This document covers the following topics:


Overview

The EntireX Listener for IBM® MQ receives asynchronous and synchronous messages from an IBM MQ queue and calls a standard RPC server. The Listener for IBM MQ uses the IBM® MQ base Java classes from IBM. It can connect to an IBM MQ either as an IBM MQ client using TCP/IP (client mode) or in so-called bindings mode where it is connected directly to IBM® MQ running on the same machine. Note that on z/OS, only bindings mode is supported. If the Listener for IBM MQ wants to connect in client mode via TCP/IP to an MQ server on z/OS, the client attachment feature needs to be installed on the target queue manager.

The Listener for IBM MQ runs as a listener on an MQ queue and processes MQ messages. It receives an MQ message and sends the message to an RPC server. A synchronous scenario is possible if the MQ message is a request message that specifies a reply queue. In this case the result returned by the RPC server is sent back as an MQ message to the reply queue. For possibilites on how MQ messges are mapped to RPC data see Mapping RPC Data to the MQ Message Buffer. The image below illustrate message transport when receiving MQ messages.

Listening for Messages on an MQ Queue

graphics/intro_listen.png

Note:
All messages retrieved by the Listener for IBM MQ from the MQ listen queue are passed to the same RPC service. Messages are retrieved in the order they appear on the queue.