Intro on Messaging and MQSeries

7/30/2019 Intro on Messaging and MQSeries

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IBM MQ SERIES

An Introduction to Messaging and MQSeries


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Business Insights. Technology Leadership

Messaging and Queuing

Message queuing is a method of program-to program communication.

Messaging is the technique which two Programs/Humans/Objects uses to

communicate.

Here the two parties involved in messaging do not directly talk to each

other.

Queuing refers to two parties using queues to communicate with each other.

Asynchronous messagingSender doesnt wait for the reply, but continues to do his next task

Synchronous messagingSender waits for the reply from the receiver, before proceeding to his next task


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Types of Messaging

Point to point messaging Publish/Subscribe messaging

Producer 1

Queue 2 Consumer 1

Producer 2

Queue 2 Consumer 2

Producer 3

Consumer 2

Producer 1

Producer 2

Consumer 1

Topic


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Point to point messagingThe sending application/client establishes a named message queue in the

broker/server and sends messages to this queue.

The receiving client registers with the broker to receive messages posted to thisqueue.

There is a one-to-one relationship between the sending and receiving clients.

Supports look-ahead or primitive browsing operations on queues, without removing messages on thequeue

Point to Point Messaging

Producer 1

Queue 2 Consumer 1

Producer 2

Queue 2 Consumer 2

Producer 3


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Publish/Subscribe messagingClients can produce messages for an unknown, and/or unlimited, number of subscribers; that is,

publish/subscribe messaging supports 1-to-n messaging operations.

Subscribing clients have the choice between durable and nondurable connections to the server.

Publish and Subscribe Messaging

Consumer 2

Producer 1

Producer 2

Consumer 1

Topic


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Messaging products

MQSeriesMSMQ

BEA Tuxedo

JMS


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MQSeries - for messaging services.MQSeries Integrator - for Business Integration.

MQSeries - For complete Work Flow Solution for an

organization.

MQSeries Everyplace - MQServer, which operates on low memory devices like

PDA. This MQServer will interact with base MQSeries server.

MQSeries Family


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MQSeries Overview

MQSeries is a Middleware for Commercial messaging and queuingMQSeries is a communications system

It provides an assured, asynchronous, once-only delivery of data across a broad

range of hardware and software platforms

MQSeries provides transaction oriented store-and-forward messaging services with

assured delivery

MQSeries is available for a variety of software platforms (approx. 35 platforms

MVS,Windows NT, AIX, OS2, Linux, Palm OS / Windows CE.)


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MQSeries Components

MQSeries supports client-server configurations for MQSeries applications and has components.

MQ Series Client (Slim client and Fat client)

MQSeries client accepts MQSeries calls from applications and pass them to an MQSeries server

machine.

MQ Series Server

MQSeries server is a queue manager that provides queuing services to one or more clients.

Note: All the MQSeries objects (for example, queues) exist only on the MQSeries server machine.


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MQSeries Client and Server ConnectionConnection options

MQ Servers can be accessed by

Native MQ Clients which are MQ Clients installed on same platform to that of the MQServer.

Java clients, to communicate with an MQ Server, can use of MQ Series Classes for Java

Java clients can communicate with any MQServer in 2 different modes.

As an MQSeries Client using TCP/IP

In this mode, server will be listening at port 1414(default MQ port) and the client will

connect to the server over TCP/IP.

This is very useful when client and server are in different platforms and

communicating over TCP/IP network.

In bindings mode, directly connecting to MQ Series Server

In this mode, MQ Java uses the Java Native Interface (JNI) to call directly into the

existing queue manager API, rather than communicating through a network.This provides better performance for MQSeries applications than using network

connections.


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MQSeries Objects

The MQSeries Objects -

Queue managers

Queues

Channels

Process definitions

Listeners

Queue-sharing groups(MQSeries for OS/390, V2.2 with sysplex only)

Namelists (MQSeries for OS/390 and MQSeries Version 5.1 products only)

Storage classes(MQSeries for OS/390 only)


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MQSeries Objects - Queue Manager

Queue ManagerQueue manager is the program that provides messaging services to applications.

The queue manager ensures that messages are sent to the correct queue or are

routed to another queue manager.

The queue manager processes both the MQI calls that are issued to it, and the

commands that are submitted to it.

The queue manager generates the appropriate completion codes for each call orcommand.

Queue Manager manages everything under it.


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MQSeries Objects - Queues

MQSeries Queues

Queue is a MQSeries Object.

A Queue is a container for messages.

A Message queue is owned and maintained by a queue manager.

Prerequisites

Even before creating a queue, a queue managermust have been created and must be running, and its

command server must be running.


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MQSeries Objects -Queues

Queues are the objects of queue manager for storing messages.Types of QueuesLocal Queue

Remote Queue & Remote Queue Definition

Transmission Queue

Dynamic Queue

Alias Queue

Model Queue

Reply to QueueDead Letter Queue

Cluster Queue

Repository Queue

Initiation queues

System command queue & System default queues

Channel queues & Event queues


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MQSeries Objects - Channels

Two types of ChannelsMQI Channel

A communication channel connecting MQS Client to a Queue Manager in its MQS Server m/c.

- Client Connection Channel - Server Connection Channel

Message Channel

A communication channel between Client and Server.

- Sending Channel - Receiver Channel

A message channel connects two queue managers via message channel agents (MCA's).

Channels for Clusters- Cluster Sending Channel - Cluster Receiver Channel

Other Channels-Requester Channel - Server Channel


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MQSeries Objects - Channels

Defining MQI ChannelsAutomatically defined channels

- SYSTEM.AUTO.RECEIVER - SYSTEM.AUTO.SVRCONN

User defined channelsThere are two ways of creating the channel definitions and giving the MQSeries application on the

MQSeries client machine access to the channel.

-Create one channel definition on the MQSeries client and the other on the server.

-Create both channel definitions on the server machine


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MQSeries Objects - Process Definitions

Process DefinitionA Process Definition object defines an application to the Queue Manager.

This Definition should contain the name of the program and its path to be triggered when a

message arrives on it.

Example.

On WinNT Environment.

A .bat file to be triggered.

On Aix Environment.A Batch program to be triggered.

On OS390 Environment.

A CICS Transaction to be triggered.


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MQSeries Objects - Listener

ListenerA Listener is a program which listens on the receiving channel for incoming

messages.

The default port no on which the Listener listens on is 1414.


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MQSeries Objects - Listener

Trigger MonitorsTrigger Monitor an program or application which servers initiation queues

It is a continuously running program which keeps monitoring initiation queues.


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MQSeries Objects - Message Channel Agents

Message Channel Agents (MCA)A message channel agent is a program which control sending and receiving of

messages

There is one message channel agent at each end of a channel.

One MCA takes messages from the transmission queue and puts them on the

communication link.

The other MCA receives messages and delivers them onto a queue on the remotequeue manager.

A message channel agent is called a caller MCA if it initiated the communication,

otherwise it is called a responder MCA.

.


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MQSeries Messages

Limitations on the length of MQ Message.

A MQ Message can be up to 4 MB or 100 MB long, depending on the MQSeries version youuse.

MQSeries Version 5 (for distributed platforms) supports a maximum message length of 100 MB.

MQS Messages Components-

Application Data

Message Descriptor

Application DataThe Application using the message defines the content of the message and its structure.

Message Descriptor

The message descriptor identifies the message and contains other control information.

B i I i h T h l L d hi


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MQSeries Messages

Message Descriptor

Version Return Address

Message ID / Correlation ID Format

Persistent / non-persistent Sender application and Type

Priority Report options / Feedback (COA, COD)

Date and Time Backout counter Lifetime of a message Segmenting / Grouping information

B i I i ht T h l L d hi


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MQSeries Messages

Message Segmenting and Grouping

Distribution Lists

B i I i ht T h l L d hi


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Message

A Message is a communication sent between programs

Message Types

Datagram

Request

Reply

Report

MQSeries Messages

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MQSeries - Guidelines

Guidelines for creating queue managers

Specify a unique queue manager nameLimit the number of queue managers ( There is actually no limit )

Specify a default queue manager

Specify a dead-letter queue

Specify a default transmission queue

Specify the logging parameters you require

Intro on Messaging and MQSeries

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