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App Service Configurable - Pipeline Per Topics

The pipeline configuration in Getting Started section is the preferred way if your use case only requires a single functions pipeline. For use cases that require multiple functions pipelines in order to process the data differently based on the profile, device or source for the Event, there is the Pipeline Per Topics feature. This feature allows multiple pipelines to be configured in the Writable.Pipeline.PerTopicPipelines section. This section is a map of pipelines. The map key must be unique, but the value isn't used, so it can be any value.

Each pipeline is defined by the following configuration elements:

Element Value Description
Id unique ID This is the unique ID given to each pipeline
Topics List of topics Comma separated list of topics that control when the pipeline is executed. See the Pipeline Per Topics advanced topic section for details on using wildcards in the topic.
ExecutionOrder List of functions Comma separated list of function names, in order, that the pipeline will execute. Same as ExecutionOrder in the above example in the Getting Started section

Example - Writable.Pipeline.PerTopicPipelines

In this example Events from the device Random-Float-Device are transformed to JSON and then HTTP exported. At the same time, Events for the source Int8 are transformed to XML and then HTTP exported to same endpoint. Note the custom naming for TransformJson and TransformXml. This is taking advantage of the Multiple Instances of a Function described below.

        Id: float-pipeline
        Topics: "edgex/events/device/+/Random-Float-Device/#, edgex/events/device/+/Random-Integer-Device/#"
        ExecutionOrder: "TransformJson, HTTPExport"
        Id: int8-pipeline
        Topic: edgex/events/device/+/+/+/Int8
        ExecutionOrder: "TransformXml, HTTPExport"
          FilterValues: "Random-Float-Device, Random-Integer-Device"
          Type: json
          Type: xml
          Method: post
          MimeType: application/xml
          Url: ""


The Pipeline Per Topics feature is targeted for EdgeX MessageBus and External MQTT triggers, but can be used with Custom or HTTP triggers. When used with the HTTP trigger the incoming topic will always be blank, so the pipeline's topics must contain a single topic set to the # wildcard so that all messages received are processed by the pipeline.