Starting external client without Process engine running



if i start an external client and the process engine is not running in the moment, i got a lot of ugly exceptions…
what i would expect would be something like “info message: Server is not running in the moment, i will reconnect later… have nice day” instead of ugly exceptions spamming my log.
is there anything i can do to avoid this exceptions… I mean in an network environment it is expected behavior that a server might be not available some time!

Exception example:
2019-06-12 09:54:56.550 [ERROR] [TopicSubscriptionManager] o.c.b.client.logError:70 - TASK/CLIENT-03001 Exception while fetch and lock task.
org.camunda.bpm.client.impl.EngineClientException: TASK/CLIENT-02002 Exception while establishing connection for request ‘POST http://localhost:8080/enrichmentservice/api/rest/1.0/rest/external-task/fetchAndLock HTTP/1.1’


I agree - I think it would be better if it was a little less angry about not being able to find the server.

If you’re interested you could create a pull request for the project.


we will think about it…

we were already discussing in our company if we have to do a own implementation of the external client, because in the moment it feels not very stable in error scenarios.

maybe you can look at another question of mine: Camunda External client: TASK/CLIENT-02002 Exception while establishing connection for request

i am not sure if this is an error in the process engine or the spring boot integration or even in the external client…


Personally I think it’s better to start with what is there and work with it, for a number of reasons.

  • Camunda will support the client by adding any new External Task Features as they are released with the engine. If you built you own, you’d need to re-implement these new features.
  • As more community members contribute to the project it will become more stable and more people will use it which will help getting more contributions. This means that probably that other people have will potentially be fixed perhaps before you even come across them.