External queue

[raficruz]

Hello,
I am newbee with Camunda and read some of the documentation, so I have some doubts.
I modeled a process, which uses an ExternalTask. If I understand correctly, each ExternalTask creates a new topic in a Camunda internal queue that will be consumed by a subscribed Worker.
Is it possible to use an external queue like a Pub/Sub as a external activity or I need to create a ServiceTask and handle the publication in the external queue inside it?

[tmetzke]

Hi @raficruz,

You understood that correctly, yes, they are stored internally.

You may want to have a look at other topics like this one here:

External Task not found: Camunda API and Kafka

Hi all, My current architecture is like this: [56] Spring Boot application start a new process vía API. On camunda instance, I have a plugin which publish every external task in Kafka. Once the first external task starts, Camunda publish an event in Kafka, Spring Boot application try to fetch and lock this task, but I receive and error due there is no task. If I open the cockpit, there is already a task, but I’m thinking maybe, the event is published too fast, and the task is not yet creat…

An external system like Kafka is used here to handle the queue of ExternalTasks.

Hope that helps.

Best,
Tobias

[pipeline]

Hi,
As @tmetzke says, I’m using Kafka as external queue to process all external tasks, or user tasks events.
I created a plugin for Camunda and when receive a new external task event, I puliblish into a Kafka topic. Other systems are subscribed to this topic an process the business logic for this external tasks.

Other way to interact with external tasks is use the External Task Client for Java (or Javascript) https://github.com/camunda/camunda-external-task-client-java.
In this case is a pooling system instead a reactive, but may fit for your solution.

[raficruz]

You helped me a lot.
The approach you showed me solve totally my problem.
I have tested another approach using messaging and I believe it will work too.
Thank you so much.