Introduction to WebSphere Messager Broker

MB Overview

MB the full name is message broker, which is the messaging agent. The word "message" a few years ago compared to fire, message middleware also sold very hot, at that time it seems that the product of the Java EE to "news", "middleware" has a little relationship to show the trend. I think beginners only need to remember the "message" of the asynchronous, that is, "message" and the traditional network connection, remote method call the biggest difference, that is, once you send the message, do not care about it, the middleware will handle everything, the problem will notify you, so that you can better separate business logic. The message as an e-mail, then the traditional network connection is by you to send letters, and middleware is like the post office, it to provide courier services, and can cross-border, inter-language, completely without your concern (equivalent to the middleware can connect heterogeneous platform), users only need to wait at the door to receive mail.

before you say "agent," start by talking about the basic concepts of MQ. The MQ is the message queue, Message Queuing, IBM's flagship message middleware product, IBM almost all SOA related products are built on the MQ, without MQ powerful message transmission capabilities, so many IBM products can not be done. Not to repeat the MQ feature here, beginners just need to take MQ as a very reliable transmission channel, you just put things inside, MQ will send the message to the destination.

What about "acting" with the powerful MQ ? If you have used MQ, or a similar product such as Apache's Open source JMS product "ActiveMQ", you will find that although you do not have to consider network connectivity and platform heterogeneity with MQ, you specify the destination when you configure it, and when you use MQ programming, such as setting the IP address. Such a program is still very large coupling, in case the IP of a component has changed, all the components related to him have to be changed, and then modify the configuration file, re-rewrite code. At this time the role of "agent" began to highlight.

MQ queues for all components can be connected directly to MB, which is equivalent to a public service center. MB to receive all messages, and then automatically analyze the content, find the corresponding destination, routing and forwarding, as you write, just specify the recipient's name, ID card, even if the addressee moved to the ends of the Earth, as long as he was in the MB post office, the MB can give him the letter, This further separates the business from the underlying communication, and I just need to know the "he" in the business concept to give the message to him. In addition, MB can also be used for message conversion, which is like automatic translation of letters, I can now write a letter in Chinese to bin Laden, I do not need to know where he is specifically hidden, the letter will be automatically translated into Afghan text, sent to Bin Laden's hand.

Therefore, the two core functions of the agent are "message routing" and "message format conversion". MB is also essentially a service bus, all of the service components are plugged into MB, and the service will plug the message to MB,MB to decide how to forward it, so that the service becomes a separate entity, and the coupling of other services is further reduced, thus reaching the realm of SOA.

MB first glance

Having said so many principles, I finally began to talk about the specific contents of MB. The following image is taken from the IBM Red Book, which is the overall MB architecture, which I briefly describe.

As you can see, there are two chunks of content in MB, one is toolkit, that is, the development environment, we will talk about it later, and another is broker domain, which is the proxy field. There are two core components in the proxy domain, one Configuration Manager and one agent broker.

The Configuration Manager is much like the MQ Queue Manager, or the deployment manager of was, and it's a management role, and in MB of course, it's a lot of broker management. The management and maintenance operations of the broker are actually done through Configuration Manager.

Broker Broker is a true embodiment of MB design ideas, the above image has the same thing as a flowchart, that is, message flow, is the flow of information (from where to flow in, and then from where), and Messageset, that is, the message set, It is a description of what the message looks like, its structure, its content. In fact, the message flow corresponds to the word "route" as described above, and the message set corresponds to "format conversion", so you must be clear about the format of the two messages in order to define the rules that are converted to each other.

MB the periphery is various types of applications, they can access MB in a variety of ways, can be webservice, can also be database, file, HTTP connection, etc., not necessarily limited to MQ

The cylinder represents the database, which is known to all it people. Because many megabytes of information, including configuration information, and the broker's run-time information are saved through the database. The broker itself can also manipulate the database, and you can delete and modify a database on a node of the process.

isthe interface of WMBT (WEBSPHEREMB toolkit)

As you can see, WMBT is eclipse-based, so most Java developers should be able to get started quickly. The development of the MB program and the development of the Java EE program is similar, is to create a new project, and then edit, and finally deploy.

1 Number area is a message flow that can be seen very intuitively: read from MQ -compute (Convert to Web Service format)--Send HTTP request to Web service url--compute (convert back to MQ message format)--put in MQ

2 area is the node selection panel, MB comes with dozens of nodes for us to choose, and we can also create our own nodes

3 Number area is the properties panel, where you can edit the properties of a node when you select a node

4 area is a domain connection panel, the development of a good message flow and message format, you must first connect to the corresponding Configuration Manager in the MBT, and then deploy the packaged process to the corresponding broker, this process can also be completed by the command line

5 area is similar to Eclipse 's project collection, which is all MB items

Summarize

or an analogy. First, we think of MB as a powerful router, it supports a variety of access methods, that is, the number of ports on the MB router, MQ is a more common way, so MQ is like the common RJ45 interface of the 5 twisted pair. However, the MB also supports various access standards such as JMS and SCADA. Inside MB, our administrator defines the routing rules (writing the message flow). Second, signals from MQ can be converted to other network protocol signals (message format conversions), which are similar to bridge functions that can span different networks. At the same time, the performance of MB is very good, can be large data exchange, which is very much like a switch. Finally, the MB can understand the business logic, its route not only as the router for the message header routing, but also based on the message's business content to route, similar to the application gateway.

Introduction to WebSphere Messager Broker