External Tasks

The External tasks concept was introduced in v. 7.4. So far, only two operations existed to deal with external tasks: Fetch & Lock and Complete (read more in our docs). These operations may be enough in most of the use cases, but can also cause a lot of inconveniences:

In Camunda there is a concept called External Tasks. See External Tasks allows new Use Cases with Camunda BPM or External Tasks in the docs. The basic idea is simple: Camunda does not actively call a service (which would be PUSH), but worker fetch work items queued for them (PULL). Whenever a worker finishes his work item, he reports completion back to Camunda.  Workers can use the Java API, but most often leverage the REST API, as this allows to run workers as own process. This again allows to scale the workers independently and use whatever language you like to implement them. Also it allows on-premise workers in your private network access a cloud hosted engine.Whenever you are talking REST...

In a recent Blog Post I wrote about a concept we call “External Tasks” where services were not actively called from the Workflow Engine (PUSH) but where “Workers” retrieve their tasks from the Workflow Engine (PULL). We discussed this a lot and got so much feedback that we decided to support this pattern out-of-the-box in Camunda BPM 7.4. Let’s have a look at an example (yes – we do have customers implementing video processing :-)): In this case transcoding and uploading a video file can take ages. It is done by special software which often does not have a SOAP or REST API to call. So in this case it is much easier to make an External Task out of...