IBM WebSphere MQ

By Parth Shah

1. Introduction

• It is a messaging middleware that allows independent and potentially non-concurrent applications on a distributed system to securely communicate with each other regardless of where application resides.

• MQ facilitates the secure and reliable communication between applications, systems, services and file by sending and receiving message data via messaging queues.

1.1 Message

• Non-persistent messages: Non-persistent messages can be lost if network communication between queue managers fails, a queue manager is restarted to perform maintenance, or an abrupt failure occurs that ends a queue manager un-cleanly.

• Persistent messages: WebSphere MQ assures exactly one delivery of persistent messages. This means that WebSphere MQ does not discard a persistent message through network failures, delivery failures, or planned restarts of the queue manager.

2. MQ Infrastructure

2.1 Queue Manager• A queue managers is a container of MQ objects. • Multiple queue managers can run on a single physical server. • The queue managers maintain the queues and all of the

messages that reside on those queues.• Queue managers are tolerant to failures, maintaining the

integrity of the business-critical data flowing through the queues.

2.2 Queue

A queue is a container of messages. New messages are placed at the end of the queue, and messages are usually retrieved from the front of the queue.

2.2.1 Types of Queues

• Local Queue• Transmission Queue• Alias Queue• Model Queue• Remote Queue• Dead Letter Queue

2.3 Channels

• The queue managers within the infrastructure are connected with channels.

• Messages automatically flow across these channels, from the initial producer of a message to the consumer of that message, based on the configuration of the queue managers in the infrastructure.

2.3.1 Types of Channels

• Receiver Channel• Requester Channel• Sender Channel• Server Channel• Sender-Receiver Channel

• Requester-Sender Channel• Requester-Server Channel• Server-receiver channels

2.4 Listener

• It is a service of MQ. Every Queue Manager will have a listener defined with unique port number. Default port number is 1414. Listener act as a mediator between external application or queue managers connecting to the queue manager. To contact queue manager we should approach through listener.

• It is a component of a WebSphere MQ queue manager, or a WebSphere MQ client product, that forms one half of a channel, establishing network communications with, or corresponding to network communications from, a partner MCA.

3. WebSphere MQ control commands

• dspmq: Display a list of queue managers that exist on the machine and their status.

• crtmqm: Create a queue manager.• strmqm: Start a queue manager on UNIX.• endmqm: End (stop) a queue manager.• Runmqsc: Interactive console for MQSC commands.• Dspmqver: Report information about the current maintenance

level of the WebSphere MQ installation.

3.1 Create a MQ Queue

• Below example creates a MQ queue with queue name lets say MQ.REQUEST

• Example:

3.2 Create a MQ Listener• Below example creates a listener on queue manager QMGR1 using TCP protocol on

port 1414.• Example:

3.3 Create a MQ channel• Below example creates MQ channel channel_test with type as sevection channel SVRCONN.

Thank YouBy Parth Shah