What are Bridges?
Updated: November 27, 2015
Bridges are entities that help in message mediation. Message mediation involves performing a series of processing steps such as decoding, validating, enriching, and transforming the message as it travels from its originating source to its destination. If we consider the ESB pattern where systems are loosely coupled and are communicating via messages, bridges can be thought of as a combination of an on-ramp, a pipeline, and an off-ramp. Following are the characteristics of bridges provided with BizTalk Services:
Bridges are composed of stages and activities where each stage is a message processing unit in itself.
Each stage of a bridge is atomic, which means either a message completes a stage or not. A stage can be turned on or off, indicating whether to process a message or simply let it pass through.
The following diagram presents a pictorial representation of how different stages of a pipeline are tied together:
There are two types of bridge templates –generic and specific. A generic template is a customizable template and is the starting point of specific templates. You can use this template to create a customized bridge that suits your requirements. A specific template is a specialized case of the generic template, which is designed for a specific use. One example of a specific template is the XML bridge template that specializes in processing XML messages. This release of BizTalk Services provides only the specific bridge templates – XML One-Way Bridge, XML Request-Reply Bridge, and Pass-Through Bridge. This section provides more information about these bridges, including the stages, uses of the template, and so on.