WMB7 Publish Subscribe

© 2010 IBM Corporation

WebSphere Message Broker Version 7

Publish / subscribe in Message Broker V7

Jonathan Woodford

Jonathan Woodford, Message Broker Development

© 2010 IBM Corporation2

Agenda

� Background

� Topic Based Publish Subscribe

� Content Based Publish Subscribe

� Migration

Topic: INFO/#

Filter: year > 1993 AND cast = “%Kelsey Grammer%”

Message Broker

MQ

Interface

Content BasedFiltering



Example of a Flow that handles ‘Publish / Subscribe’

� Publication messages handled within the flow– Publication node receives publication messages and distributes to the subscribers

matching the topic within the publication message

� MQ based subscription messages registered via a special queue– SYSTEM.BROKER.CONTROL.QUEUE– Do not need to define a flow to handle subscription requests


Justification

� There were two separate Publish / Subscribe engines –MQ Publish and Subscribe–Message Broker Publish and Subscribe

� Use completely different code bases

� Use different administration and configuration options / Tools

� Different security model

� Different capability!


Publish Subscribe History

� MQ v6 provided basic Publish / Subscribe capability

� If additional function was required, Message Broker / Event Broker could be used

� New enhancements introduced into MQ v7

Publish Subscribe function MQ v6.x Message

Broker v6.x

Topic based matching Yes Yes

Retained publication support Yes Yes

RFH (1) Support Yes Yes

RFH 2 Support No Yes

Security / Access Control (ACLs) No Yes

Centralised graphical

configuration

No Yes

High availability option No Yes

High performance non-

persistent option

No Yes

Available on all platforms Not

supported

on z/OS

Yes


MQ v7.0.x Enhancements

Publish Subscribe function MQ v7.x Message Broker

v6

Topic based matching Yes Yes

Retained publication support Yes Yes

RFH (1) Support Yes Yes

RFH 2 Support Yes Yes

Security / Access Control (ACLs) Yes Yes

Centralised graphical

configuration

Yes Yes

High availability option Yes Yes

High performance non-persistent

option

Yes Yes

Available on all platforms Yes Yes

‘Put to topic’ Yes No

� MQ v7.0.x significantly enhanced the Publish Subscribe function


Topic Based Publish Subscribe


MQ PubSub Exploitation within Message Broker

� Publication node re-written to interface with the matching engine within MQ

– Forwards publication messages to MQ

• Parses message being propagated to Publication node and calls MQ API (v7) to allow MQ to match and deliver to subscribers

– The Publication node has the same external behaviour as previous versions

• Supports ‘Publication’ and ‘Delete Publication’ requests.

• Supports RFH & RFH2

• Support subscription points for RFH2 messages

• Supports streams for RFH messages

� Subscription requests handled by MQ

– Queued subscriptions handled by MQ’s Queued Publish Subscribe Interface

• Owns SYSTEM.BROKER.CONTROL.QUEUE

• PSMODE must be set to ‘ENABLED’ if using queued (RFH/2) Publish Subscribe

PubSub Engine

(MQ)

PubSub Engine


9

� Terminals provided on Publication node

� Drives flow depending on subscribers matching publication

– No-match terminal

• If there are no matching subscribers

– Out terminal

• If one or more subscribers match

� Propagates same message assembly as input.

� Has no effect on delete publication message requests

Publication node - No-match & Out terminals


Content Filtering Based Publish Subscribe


Content Based Filtering

� Content based filtering allows a subscriber to restrict the messages that it wants to receive

– When a client registers a subscription, it can specify a filter to be applied to the content of fields within each publication message

– The filter itself is entered as an SQL expression

• Body.Name LIKE 'Smit%'

� The MQv7.0.1 matching engine supports filtering on the header (Message Properties) of the message

� Message Broker supports filtering on the whole message, including the body of the message

� MQ queue manager will use message body parsing provided by MB to support Content Based Filtering

– Message Broker building on the function provided by MQ

� Any ESQL Expression supported with below correlation names

– Root.

– Body.

– Properties.

– ‘Dynamic’

• Any name excluding defined set

� Supports Namespaces

� Builds on constants provided by MQ (Including JMS Constants)– JMSCorrelationID, JMSDeliveryMode, JMSDestination, JMSExpiration, JMSPriority, JMSReplyTo, JMSTimestamp,

JMSType

Message Broker

MQ

Interface



Topic: INFO/#

Filter: year > 1993 AND cast = “%Kelsey Grammer%”


Content Based filtering Configuration� Service runs within nominated execution groups

� If Message Broker does not have at least one execution group enabled for Content Based Filtering, MQ can only support ‘Message Selection’ (for MPs).

– Message Broker enables ‘MQ’ to support Extended Message Selection / Content Based Filtering

� All nominated execution groups must have ALL of the required message sets deployed if using MRM

� No flow required to support Content Based Filtering

� Can be enabled depending on users preference (default is disabled)– MBX– ConfigMgr Proxy– CommandLine (mqsichangeProperties)

• mqsichangeproperties MyBrk –e default –o ContentBasedFiltering –n cbfEnabled –v true

� Options– Content Based Filtering Enabled / Disabled– Number of Validation Threads (1 - 32)– Number of Evaluation Threads (1 - 32)


1

4

Retargetting of Components

� Username Server

– Provides security (user / group) information to the Broker

– Allows ACLs to be defined for certain users– Primarily used for Publish Subscribe

• No longer required due to Publish Subscribe being handled by MQ

� SCADA nodes– Publish Subscribe transport

• Better placed within Base MQ

• Transport has been picked up by MQ

� RealTime node

– Replaced with the high performance options (MQ's streaming client

technology) provided within MQv7

• Batched get

• Fire & Forget

– Scribble sample updated to remove Realtime transport.


1

5

MB SubscriptionsPanel

MQ SubscriptionsPanel


1

6

MB ‘Topic’Configuration

MQ ‘Topic’Configuration


Migration Paths


1

8

Supported Migration Paths

� Migration from Event Broker to MQ v7.0.1• Event Broker is a subset of Message Broker

Code stabilised at Event Broker v6.0

• Requires MB to support Content Based Filtering

� Migration from Event Broker to Message Broker

• Continues to support Content Based Filtering

� Migration from Message Broker v6.x to Message Broker v7.

– Supported versions

• Message Broker v6.1

• Message Broker v6.0

� Note that Message Broker v7.0 pre-reqs MQ v7.0.1


1

9

Features that will help you to migrate

� MB v7 can be installed on the same machine as, and run alongside, all previous versions of the product

� Single command to migrate runtime components between versions (mqsimigratecomponents)

� Single command to migrate Publish Subscribe state (migmbbrk)

� No redeploys required if not using SCADA or RealTimenodes

� The v7 broker can be migrated back to v6.1 or v6.0


2

0

State Migration Tool

� Allows the Publish Subscribe state held within Message Broker to be migrated to MQ– Subscriptions– Retained Publications– ACLs

• Generates script to migrate ‘positive’ ACLs

� Shipped in MQ v7.0.1• Command called ‘migmbbrk’

� Required when using any aspect of Publish Subscribe– Directly exploiting PubSub via Publication node– Accounting and Statistics– Monitoring


2

1

State Migration Tool

� May be run against MB v6.0 / 6.1 or EB v6.0– Can not be run against an MB v7.0 broker

• State no-longer held within MB

� migmbbrk needs to be run twice1)Creates topic objects within MQ. It also generates the security script [-t]2)Populates MQ matchspace (subscriptions and retained publications) [-c]

� Usagemigmbbrk [-r] [-t] [-c] [-o] [-s] [-z] [-l] -b BrokerName• -t / -c create topic objects / migrate subscriptions & publication

• -r Rehearsal

• -b Broker name• -o Overwrite (force if a subscription / retained publication already exists)

• -z Force a migration if migration has already been completed

• -s Clear out any previous data before re-attempting migration

• -l Leave broker running, otherwise it will be shutdown.

� Produces log file to record migration status


2

2

V7.0.1 QMgr

MB Migration Approach #1

Machine A’s File System

MB V6 or V6.1 Product Install

BrokerA ConfigMgr

MB V7 Product Install

V6.x Command Console

migmbbrk –t ………

Set PubSub ACLs according to generated script

migmbbrk –c ………

V7 Command Console

mqsimigratecomponents BrokerA

PubSubState

PubSubState


2

3

V7.0.1 QMgr BV7.0.1 QMgr

MB Migration Approach #2

Machine A’s File System

MB V6 or V6.1 Product Install

BrokerA ConfigMgr

MB V7 Product Install

BrokerB

PubSubState

PubSubState


Collectives Migration

� MB allows brokers to be interconnected and logically share a single matchspace by joining brokers within a 'collective'.

– MQ v7.0.1 supports PubSub clusters which uses a different protocol

� All brokers will need to be migrated together

� For each broker in the Collective perform the following steps

� Remove broker from Collective

� Migrate broker as described in migration approach #1

� Add queue manager associated with Broker to P/S Cluster

� Restart all brokers

Broker 5

Broker 5

Broker 6Broker 6

Broker 4

Broker 4

QMgrQMgr

QMgrQMgr

Broker 1Broker 1Broker

2Broker

2

QMgrQMgr

Broker 3

Broker 3

MB v6.x MB v7 with MQ v7

Migrate


� Questions?

WMB7 Publish Subscribe

Documents

Transcript of WMB7 Publish Subscribe