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Course materials may not be reproduced in whole or in part without the prior written permission of IBM. Copyright IBM Corporation 2011

5.4.1.1

Introduction to

WebSphere MQ

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Copyright IBM Corporation 2011

Unit objectives

After completing this unit, you should be able to:

Explain the positioning of messaging and queuing in the current

business environment

Provide a high-level view of WebSphere MQ functions

Describe the breadth of coverage of WebSphere MQ products

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The enterprise IT environment of today

I T e n v i r o n m e n t s a r e in c r e a s i n g l y h e t e r o g e n e o u s an d c o m p l e x

Th e r o l e o f m o d e r n m i d d l e w a r e is t o i n t e g r a t e a n d s im p l i f y

Transactions

Legacy systems andapplications

Networks

Databases

Intranets

Value chainextranets

Internet

Customers

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IBM WebSphere reference architecture

Business servicesWebSphere Business Monitor

Infrastructure services

Developmentservices

WebSphereBusiness

IntegrationModeler,

WebSphereIntegration

Developer

Managementservices

Interactionservices

WebSpherePortal Server

Processservices

WebSphereProcess Server

Informationservices

WebSphere

InformationIntegrator

Partnerservices

WebSpherePartner Gateway

Businessapplication

services

WebSphereApplication Server

AccessservicesWBI and

WebSphereAdapters, HATS

Connectivity services, ESBWebSphere MQ

WebSphere Enterprise Service Bus,WebSphere Message Broker

Service registry

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Why are interfaces so expensive to build and maintain?

Application interface logic is intertwined with business logic

Tightly integrated interfaces are difficult to change

The more interfaces, the more complex the application interface

logic may exceed business logic.

Reuse becomes difficult and impractical

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Service-oriented architecture (SOA)

Message

queuing

Abstractsconnectivity

logic from

application

Traditionalmessage

brokering

Abstractsconnectivity and

mediation logic

from application

Messageand

service brokering

Reducesapplication to core

business functions

(that is, a service)

Application Application

Connectivity,

mediation, andadditional logic

Direct

connectivity

Connectivity,mediation, and

additional logic

buried in application

Application

Connectivity

logic

SERVICES

Connectivity,

mediation, andadditional

logic

Mediation and

additional logic

Additionallogic

Connectivity and

mediation logic

Degree of flexibility and reuse

Linesof

code

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Program-to-program communication

BA

QueueApplication Application

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Synchronous application design model

BA

Queue 1

Queue 2

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Extended asynchronous application design model

B

A

C

Queue 1

Queue 2

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Time independence

BA

BA

BA

BA

Not available

Not available

Not available

Not available

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Three styles of communication

C o n v e r s a t i o n a l

A B

A

B

Me s s a g i n g

C a l l - a n d - r e t u r n

A

Call B

B

Returnto A

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WebSphere MQ eliminates application network concerns

ApplicationsApplications

Network

Networkinginterface

Applications

MQI

Queuemanager

Applications

MQI

Queuemanager

Networkinginterface

Networkinginterface

MCAMCA

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Local and remote queues concept

Program BProgram A Program C

QM2:Local

queue,transmit

queue

Q1: Localqueue

Queuemanager

QM1

Queuemanager

QM2

Q2: Localqueue

System 1 System 2

MQPUTQ2, QM2

MQPUT Q1 MQGET Q1 MQGET Q2MQI

Dead letterqueue

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MQI calls

Major calls

MQCONN

MQCONNX

MQDISC

MQOPEN

MQCLOSE

MQPUT

MQPUT1

MQGET MQSUB

MQSUBRQ

Minor calls MQBEGIN

MQCMIT

MQBACK

MQINQ

MQSET

Applications

MQI

Queuemanager

Queue managerobject

Namelist objectProcess

definitionobject

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Message composition

Set by application and queue manager Header

MQMD (message descriptor)

Application data

Any sequence of bytes

Meaningful only to the sending and receiving applications

Not meaningful to the queue manager

Application dataHeader

Message = header + application data

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Parallel processing application design

Car

Flight

Hotel

MQPUT CAR.RENTAL

MQPUT FLIGHT

MQPUT HOTEL

MQGET reply-to queue

CAR.RENTAL

FLIGHT

HOTEL

MQPUT

MQPUT

MQPUT

Reply-to queue

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Triggering

Processdefinition

object

MQPUT A.Q

Program A

Trigger types: FIRST DEPTH

EVERY

Applicationqueue(A.Q)

Initiationqueue(I.Q)

Triggermonitor

1

2

34

6

5

MQGET I.Q

MQGET A.Q

Program B

Queue manager

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Client/server application model

Insurance agent

Insurance agent

Insurance agent

Applicationclients

Queue = service

Message = request Reply-to queue name in

message descriptor Multiple instances of

server possible

Insurancequotations

Applicationserver

Insurance

data

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WebSphere MQ client

WebSphere MQ

application

Communicationsstack

Client stub

WebSphere

queue manager

Communicationsstack

Serverconnection

Client system Server system

(no queue manager existson this system)

Communicationlink

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Unit of work 3

Unit of work 1

Data integrity

Unit of work

Write

Send

Sync point

ReceiveWrite

Sync point

database

database

Database

Database

Two phasecommit

Unit of work 2Write

PutSync point

A.Q(xmitq) B.Q

Get

WriteSync point

Asynchronous model

Synchronous model

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Remote queuemanager

Security

|USERID| |

Message context

Local queuemanager

Queues Administrative

commandsMCA

MCA

Authenticationencryption

Database

MQMD Application data

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Unit summary

Having completed this unit, you should be able to:

Explain the positioning of messaging and queuing in the current

business environment

Provide a high-level view of WebSphere MQ functions

Describe the breadth of coverage of WebSphere MQ products

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Checkpoint questions (1 of 2)

1. WebSphere MQ uses an interface for programs to access resources

called:

a. The program-to-program API.

b. The Message Queue Interface.c. The synchronous model.

d. Triggering.

2. True or False: WebSphere MQ only supports messaging and queuing

in an asynchronous environment.

3. True or False: In WebSphere MQ triggering, the queue managerstarts the triggered program.

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Checkpoint answers (1 of 2)

1. WebSphere MQ uses an interface for programs to access resources

called:

a. The program-to-program API.

b. The Message Queue Interface.c. The synchronous model.

d. Triggering.

Answer: b.

2. True or False: WebSphere MQ only supports messaging and queuing

in an asynchronous environment.

Answer: False. WebSphere MQ also supports messaging and queuing in a

synchronous environment.3. True or False: In WebSphere MQ triggering, the queue manager

starts the triggered program.

Answer: False. The trigger monitor starts the triggered application.

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Checkpoint questions (2 of 2)

4. A message consists of:

a. Application data.

b. A WebSphere MQ trailer.

c. A security header.d. A message descriptor.

e. All the above.

5. All WebSphere MQ messages have a header. It is the:

a. MQXQH (transmission header).

b. MQDLK (dead letter header).

c. MQMD (message descriptor).d. MQTH (trigger header).

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Checkpoint answers (2 of 2)

4. A message consists of:

a. Application data.

b. A WebSphere MQ trailer.

c. A security header.

d. A message descriptor.

e. All the above.

Answer: a and d, although it is possible for a message to contain only a messagedescriptor and no application data. Security information, known as the

message context, is part of the message descriptor.

5. All WebSphere MQ messages have a header. It is the:

a. MQXQH (transmission header).

b. MQDLK (dead letter header).

c. MQMD (message descriptor).

d. MQTH (trigger header).

Answer: c. The MQMD (message descriptor) is always included a WebSphere MQmessage.

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