Patterns: Broker Interactions for Intra- and Inter-enterprise

268 Broker Interactions for Intra- and Inter-enterprise

Figure 9-34 Real-timeOptimizedFlow node settings

Note that a topic is not defined. The topic is specified by the clients so there must

be some agreement between them to define a common name.

Deployment of the message flow is handled in the same manner as described in

“Deploy the message flow” on page 248.

9.8 Quality of service capabilities

For a broker or router the Quality of Service capabilities are greatly affected by

the qualities of the environment and that of the service providers. The following

discussion focuses on the quality of service implications when using WebSphere

Business Integration Message Broker.

9.8.1 Availability

By default, the WebSphere Business Integration Message Broker is a single

point of failure. This is easily remedied by deploying two brokers on similar

machines with an MQSeries cluster configuration. Where connection is by IP

address, an IP switching facility is required.

9.8.2 Performance

Performance and capacity planning reports are available for the WebSphere

Business Integration Message Broker in the form of SupportPacs from the

WebSphere Business Integration Message Broker Web site at:

http://www.ibm.com/software/integration/support/supportpacs/

Chapter 9. Broker solutions using WebSphere Business Integration Message Broker 269

9.8.3 Security

Security provides confidentiality and non-repudiation by authenticating the

parties involved, encrypting messages, and providing access control. Security

has additional importance if the activity occurs over the public Internet. The

service provider can have different approaches and levels of providing security

depending on the service requestor.

SSL is available for the Internet and MQSeries protocols.

A new feature of WebSphere Business Integration Message Broker is the

concept of

quality of protection.

In public internet deployments, cryptographically-based protection of messages

enhances security by preventing tampering and eavesdropping by hackers. The

authentication services currently provided by WebSphere Business Integration

Message Broker ensure that only legitimate event broker servers and clients can

connect to each other. However, a hacker may still be able to observe messages

in transit or tamper with messages on established connections. Message

protection provides security against these kinds of attacks.

Message protection features consume processor time and can slow system

throughput. However not all messages are equally sensitive, so message

protection is configurable on a per-topic basis so that you get only the protection

you really need. Some topics may get no message protection at all, others may

get channel integrity (making it impossible for hackers to insert or delete

messages undetected), or message integrity (making it impossible for hackers to

alter messages undetected), or message privacy (making it impossible for

hackers to observe message contents). The protection levels are cumulative, for

example, if you request message privacy you get message integrity and channel

integrity as well. If you request message integrity you also get channel integrity.

The higher levels of protection consume more resources than the lower levels.

You may also set message protection on internal system topics. Unlike user

topics this must be either enabled on all topics, or on none.

9.8.4 Transactionality

WebSphere Business Integration Message Broker provides transactional support

via MQSeries or supported databases.

For external activity the message flow has to enlist in a global transaction such

that all required resources are coordinated. If a message flow includes

interaction with an external user database, the message flow can be configured

such that all of its processing is coordinated within a transaction. This ensures

that all processing is either successfully completed, or no processing is