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Message Exchange Patterns for Bridges

 

Important

Microsoft Azure BizTalk Services (MABS) is being retired, and replaced with Azure Logic Apps. If you currently use MABS, then Move from BizTalk Services to Logic Appsprovides some guidance on moving your integration solutions to Logic Apps.

If you're brand new to Logic Apps, then we suggest getting started here:

Bridges being message intermediaries between the clients and services, they must support the different message exchange patterns agreed upon between the respective clients and services. Currently, the XML bridge supports two message exchange patterns – XML One-Way Bridge and XML Request-Reply Bridge. Pass-Through Bridge also supports only one-way message exchange pattern. Note that the message exchange patterns are considered at the application level, which means, that for a XML Request-Reply Bridge, the client sending a message to the service expects a response back. For XML One-Way Bridge, no such response is expected.

XML One-Way Bridge

In an XML One-Way Bridge, the client sends a message to the service but does not expect or request a response back. An XML One-Way Bridge contains the following stages:

  • Validate

  • Enrich, pre-transform

  • Transform

  • Enrich, post-transform

See Uses and Stages of Bridges.

Constraints on Using an XML One-Way Bridge

An XML One-Way Bridge can route messages to any destination that can be added to a BizTalk Service project. The only consideration is that when you route a message from a XML One-Way Bridge to two-way destination endpoints, such as Two-Way Relay Endpoint, Two-Way External Service Endpoint, or an XML Request-Reply Bridge, then the response message that is received from any of these two-way endpoints is ignored by the XML One-Way Bridge.

XML Request-Reply Bridge

In an XML Request-Reply Bridge, the client sends a message to the service and expects a response back.

Request Path

The request path of the bridge contains the following stages:

  • Validate

  • Enrich, pre-transform

  • Transform

  • Enrich, post-transform

Reply Path

The response path of the bridge contains the following stages:

  • Enrich, pre-transform

  • Transform

  • Enrich, post-transform

  • Reply Action

For more information about each of these stages, see Uses and Stages of Bridges. For more information about Reply Action, see Route and Reply Actions: Bridging Protocol Mismatch.

Constraints on Using an XML Request-Reply Bridge

You can use an XML Request-Reply Bridge only for routing messages to two-way relay endpoints, two-way external service endpoints, or other XML Request-Reply Bridge.

Pass-Through Bridge

In a Pass-Through Bridge, the client sends a message of any message type to the bridge and does not expect a response back. A Pass-Through Bridge contains only an Enrich stage and is only a one-way bridge.

Constraints on Using a Pass-Through Bridge

The constraints for a Pass-Through Bridge are same as the constraints for an XML One-Way Bridge. For more information, see Constraints on Using an XML One-Way Bridge.

See Also

What are Bridges?