Skip to main content

Outbound Channel

A channel model can be created in Flowable Design when clicking the Create button and then selecting the Channel entry in the Model Type dropdown. The regular model creation popup is then shown where a model name and key can be set. A channel model can also be created from a process or case model when selecting a channel property in the property panel of event-capable activities.

At the top of the page, the type of channel needs to be chosen: Inbound or Outbound. An inbound channel is used to received events, while an outbound channel sends them out.

An outbound channel model is similar to an inbound one, but simpler. The adapter configuration is similar as above, but for the pipeline there are no steps to configure. This is because the default pipeline consists of but two steps: the serialization and the event transformation. Both are dependent and fully defined by the serialization format which can be selected in the dropdown:

Pipeline

Kafka​

The Kafka outbound channel allows for configuring how an event should be produced to a Kafka topic.

Partition Provider​

Kafka Outbound Partition Provider UI

Flowable provides multiple options to configure the partition for a Kafka Outbound event:

  • Default - Use the default Kafka mechanism
  • Event field - Use an event field to get the partition to which the event needs to be sent
  • Round Robin - Use a Round Robin approach to determine the partition to which the event needs to be sent to. This can be a string or an expression that resolves to a string. The string can contain a comma-delimited list of partitions, or ranges of partitions (e.g. 0-5, 7, 10-15).
  • Delegate Expression - Use a Delegate expression that resolves to an instance of org.flowable.eventregistry.spring.kafka.KafkaPartitionProvider that will provide the partition to which the event needs to be sent.

AWS SNS​

The AWS SNS outbound channel allows for configuring how an event should be produced to a SNS Topic.

FIFO Topics​

SNS Outbound Properties UI

Flowable provides multiple options to configure the subject, group ID and deduplication ID of an sns outbount channel

  • Default - Use either a hardcoded string or an application property expression
  • Event field - Use an event field to get the properties to configure the AWS SNS channel properties
  • Delegate Expression - Use a Delegate expression that resolves to an instance of com.flowable.core.aws.sns.eventregistry.SnsValueProvider that will provide the value.