WMB 6.1 Basics

What ?


WMB is a broker engine that can perform message transforming and routing from different participants to different destinations based on user-defined rules, so that diverse applications can exchange information in dissimilar forms, with brokers handling the processing required for the information to arrive at the right place in the correct format.
WMB provides a connectivity layer for process engines that choreograph the flow of activities between services. It is WebSphere Message Broker’s responsibility to deliver service requests,rerouting or transforming them if appropriate.


Components
I) Broker : The broker is a set of application processes that host and run message flows.
When a message arrives at the broker from a business application, the broker processes the message before passing it on to one or more other business.The broker routes, transforms, and manipulates messages according to the logic defined in their message flow applications.
Each broker uses a database to keep the broker’s configuration information and the message sets together with message flows deployed to it, which will be loaded at the start time.


II) Execution group : Execution groups enable message flows within the broker to be grouped together.
Each broker contains a default execution group. Additional execution groups can be created as long as they are given unique names within the broker.
Each execution group is a separate operating system process and, therefore, the contents of an execution group remain separate from the contents of other execution groups within the same broker.


Note :

EG(execution group) is a process.
Why EG :  
a) Degree of separation( For different sections like : Banking, Mutual funds, Credit card related stuffs we create different EG) , for security purpose,high availability of bars'.
c) For High availability brokers should communicate to each other.



III) Configuration manager : The Configuration Manager is the interface between the Message Brokers Toolkit and the brokers in the broker domain. The Configuration Manager stores configuration details for the broker domain in an internal repository, providing a central store for resources in the broker domain.
The Configuration Manager is responsible for deploying message flow applications to the brokers. 
The Configuration Manager also reports back on the progress of the deployment and on the status of the broker.
When the Message Brokers Toolkit connects to the Configuration Manager, the status of the brokers in the domain is derived from the configuration information stored in the Configuration Manager’s internal repository.


Note :

a) CM maintains the repository with broker's Id, Queue manager, channel, port etc as & when it comes to topology.
b) CM gives UUID (Universal unique id) to Broker.
c) CM sends the request to broker in an xml file (deployment request)
For more info : http://www.ibm.com/developerworks/websphere/library/techarticles/0706_lucas/0706_lucas.html


IV) User name server : A user name server is an optional component that is required only when publish/subscribe message flow applications are running, and where extra security is required for applications to be able to publish or subscribe to topics. 
The user name server provides authentication for topic-level security for users and groups that are performing publish/subscribe operations.


Broker domain : Brokers are grouped together in broker domains. 
A broker domain contains one or more brokers and a single Configuration Manager. It can also contain a user name server.
The components in a broker domain can exist on multiple machines and operating systems, and are connected together with WebSphere MQ channels.
A broker belongs to only one broker domain.


V) Best Practice : http://andypiper.files.wordpress.com/2007/06/messagebrokercodedeploy.pdf



Supports for Administrator

a) Control commands ( MQSI Commands : System integrator)
b) Broker Toolkit.
c) Configuration manager proxy API (CMP API)
d) Websphere broker explorer.


Supports for Developers
a) MB Toolkit
b) ESQL
c) Java APIs