ServiceMix is an Emterprise Service Bus (ESB) that is based on the Java Business Integration (JBI) standard JSR 208. The JBI-based design specifies a standards-based pluggable architecture with a JVM-based runtime component called the Normalized Message Router (NMR). The Basic example demonstrates how applications communicate via the ServiceMix ESB, and the role that the NMR can play in that communication. Similar techniques could be used to plug any external 1 application or service into ServiceMix (e.g. SAP, Peoplesoft, spreadsheets, POJOs, Webservices and EJBs) and allow it to communicate with other external applications or components using ServiceMix itself.

A hypothetical business scenario, which extends the Basic Example, is that of a department store distributor. This distributor sells products from multiple wholesalers (suppliers) to various retailers (customers). The distributor presents a common interface for product ordering to each of its department store customers. However, the distributor must work with a different ordering interface for each wholesale suppliers for the products they are buying.

Using an ESB, the distributor has developed a number of components to receive department store orders and then dynamically route and transform these orders to the appropriate wholesaler. The order processing flow is described as follows:

  1. Using the distributor's web interface, a department store customer submits an order for multiple products. An HTTP request is sent to the OrderReceiver, an HTTP binding component (BC). 3
  2. The OrderReceiver sends the message to an OrderRouter service engine (SE) 4 component. This SE is responsible for parsing the order and deciding, based on the message content, which OrderTransformer should receive which part of the message (i.e., an order for a product).
  3. The OrderRouter publishes the orders to the appropriate message topics based on the message content. Specifically, the OrderRouter publishes the messages based on which wholesaler sells the item.
  4. The OrderTransformer is a service engine component, which modifies the message and puts it in a format which is readable by the wholesaler interface that will fulfill the order.
  5. Each OrderTransformer sends the modified message to the OrderProcessor.
  6. The OrderProcessor is a binding component that has two functions:
    a. It places an order to the appropriate wholesaler through the wholesaler's Webservice or proprietary interface.
    b. It also publishes a message about the order on a topic.
  7. The message on the topic is subsequently picked up by the BusinessMonitor component via the jmsTrace component.
  8. The BusinessMonitor component monitors the orders for quality assurance and business analytics, such as data mining.

The following diagram illustrates this:

Department Store Distributor's Order Processing System

  1. External means the application is outside of the ESB.
  2. Resource Adapter: a resource adapter provides connectivity between a specific external application and the ESB. In the Basic example the jencks container provides a JMS resource adapater.
  3. Binding Component (BC): a BC provides connectivity to applications that are external to the ESB.
  4. Service Engine (SE): a service engine provides business logic and transformation services to other components within the enterprise service bus.
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4 Comments

  1. Unknown User (nhb)

    The purpose of an Enterprise Service Bus (ESB), also known as a Java Business Integration (JBI) bus,

    Lisa – is ESB really also known as JBI? That doesn't seem kosher somehow –

    is to provide a mechanism for different applications to exchange messages in a protocol neutral manner and provide services for processing those messages such as message transformation and dynamic routing.

    Lisa – are messages the only things exchanged by ESB??? seems like the hype is that it is more than just messaging...

    Although not a requirement, messages exchanged between business applications are typically done asynchronously. ServiceMix is an implemenation of JSR 208, the JBI specification

    Lisa - the text around asynchronous seems to be a bit of a red herring, i.e., what is the point of adding it here? should it be more genericized, like "Messages exchanged between business applications are either synchronous or asynchronous..."

  2. Richard Petersen

    Lisa, I agree with Natalie. I think it's important to separate the purpose of the ESB initially (most ESBs are not JBI-based, as JBI is a new standard.) I'd start with a simple description of the ESB, like:

    –
    An ESB is an integration infrastructure that is
    1) distributed
    2) message-based
    3) based on open standards
    4) reliable

    As an integration infrastructure, the ESB does a number of things.
    1) The ESB transports information
    2) The ESB routes the transport of information appropriately
    3) The ESB ensures the translation or transformation of the information as required
    4) The ESB provides visibility into the transport of information.

    The ESB must also support the organization's requirements such as security, orchestration, transactionality, etc. These exist in "hard-wired" integration methods, but are not automatically available in a service-oriented architecture. One of the key requirements for the ESB is to give loosely coupled service-based integration methods a level of enterprise-class relibility, security, etc.
    –
    Then I'd get into what's so interesting about ServiceMix, which is that it's JBI-based, so the NMR plays a central role in its operation (For people unfamiliar with JBI, you might want to link them out to Sun's JBI page.)
    –
    ServiceMix is an ESB that is based on the Java Business Integration (JBI) standard. The JBI-based design specifies a standards-based pluggable architecture with a JVM-based runtime component called the Normalized Message Router (NMR). The Basic example demonstrates how applications communicate via the ServiceMix ESB, and the role that the NMR can play in that communication.
    –
    This level of introduction is pretty simple, but it might be helpful to ease people into the two concepts, showing how ServiceMix does what an ESB is supposed to do, and how the way it does it is based on the JBI standard.

    thanks
    Rich

    1. Unknown User (lmalgeri)

      Rich and Natalie, I am going to replace the first sentence with Rich's sentence "ServiceMix is an ESB based on JBI...". I am starting on beefing up the Overview so I will the rest of this
      information from Rich in there. Thanks, Lisa

      1. Unknown User (lmalgeri)

        I pointed the JBI reference off to the JSR 208 spec in Rich's first sentence because that is what is on our Home page. It looks like Sun's site references this too. If you know of a better link for this on Sun's site, then let me know and I will change it. Lisa