问题
What is the difference between a Websphere Message Broker and a Queue Manager. I guess the queue manager puts messages in the queue, takes messages out of the queue, moves messages to backout queues etc. So what is the job of the broker?
Does it sit between the publisher and the Queue Manager or between the consumer and the Queue Manager?
回答1:
Websphere MQ is a software which uses the AMQ(Asynchronous messaging protocol). You can achieve asynchronous messaging between your applications via Websphere MQ, which will make your infrastructure loosely coupled(Applications can keep working even though other applications are down in the infrastructure).
But the applications in your infrastructure may not be able to understand each others' message formats, and hence just sending the message to the target application may not be enough. You may require transformation of the message.
You can do it by writing your own program using the Websphere MQ API. Your program should be able to do the below things:
- Pick message from a specific queue (using MQGET)
- Should be able to understand the message. That is say it's an XML message. Then your program must be able to parse the XML and read the data in it.
- After reading the input message you will make your output message based on the requirements.
- Then you will either publish the message or put the message in some specific queue(say TargetQ), so that the target application can get the message. Target application will then get the message either by issuing MQGET on the TargetQ or subscribing to the topic which was published from your application.
But writing your own program will take a lot of development time and effort and also may be a bit complex.
So, IBM provided its own software to do the job, which is "Websphere Message Broker".
WMB allows you to create programs very easily and a lot faster.
Appropriate nodes in WMB will do all above steps for you. In fact it provides lot many features than the above steps.
Websphere MQ still doesn't have an HTTP listener. But, a message broker does. It allows you to host web services and have HTTP based flows etc that too in a secure way(Supports SSL).
回答2:
MQ is providing you the infrastructure for messaging: queues and topics - IBM MQ
IBM Integration Bus (formerly known as WebSphere Message Broker) allows you to apply the common EAI patterns, e.g. Routing, Transformation
Hope that helps.
Best, Patrick
回答3:
I want to add just two points: Message Broker (now IIB) includes a set of optimized and fast parsers (XML, CSV, etc) and useful mapping nodes (msg-msg, msg-db). MQ is also used for internal configuration messages coming from the Configuration Manager.
回答4:
WebSphere MQ is a solution for application-to-application communication services regardless of where your applications or data reside. Whether on a single server, separate servers of the same type, or separate servers of different architecture types, WebSphere MQ facilitates communications between applications by sending and receiving message data via messaging queues. Applications then use the information in these messages to interact with Web browsers, business logic, and databases. WebSphere MQ provides a secure and reliable transport layer for moving data unchanged in the form of messages between applications but it is not aware of the content of the messages. WebSphere MQ uses a set of small and standard application programming interfaces (APIs) that support a number of programming languages, including Visual Basic, NATURAL, COBOL, Java, and C across all platforms.
WebSphere Message Broker is built to extend WebSphere MQ, and it is capable of understanding the content of each message that it moves through the Broker. Customers can define the set of operations on each message depending on its content. The message processing nodes supplied with WebSphere Message Broker are capable of processing messages from various sources, such as Java Message Service (JMS) providers, HyperText Transfer Protocol (HTTP) calls, or data read from files. By connecting these nodes with each other, customers can define linked operations on a message as it flows from one application to its destination.
Message Broker can do the following:
- Matches and routes communications between services
- Converts between different transport protocols
- Transforms message formats between requestor and service
- Identifies and distributes business events from disparate sources
Together, WebSphere MQ and WebSphere Message Broker deliver a comprehensive publish and subscribe facility, connecting Message Broker’s broad transport and format support to WebSphere MQ’s messaging backbone. WebSphere Message Broker extends the WebSphere MQ publish and subscribe functionality with advanced function such as content-based publish and subscribe by means of an enhanced Publication node. The two products share a common publish and subscribe domain for topic- and content-based operations
回答5:
MQ is mainly for the transforming the messages from on system to another system. WMB(websphere message broker) will sit between QMGR's and transforming message along with change content of the message format as per the system requirement/Business Logic implementation.
Srinu D
来源：https://stackoverflow.com/questions/19609705/difference-between-queue-manager-and-message-broker