Amazon SWF: Where to put the decider logic?

Question

We're currently investigating the use of Amazon SWF to take care of the longer running jobs in our backend. Our architecture consists of the typical stack:

client (web/android/iOS)
----
API/Worker (Elastic Beanstalk)
----
DB (RDS)

I would like to know what would be the best place to put the SWF-decider logic. A separate EC2 instance, inside the API component, or would it make sense to separate it in another EBS-worker?

Answer 1

You can deploy your deciders to the same EC2 instances as your activity workers. However, I would not recommend deploying the API service and all the workers to the same instances.

In case of a spike in your workflows your SWF workers could scale independently of your API service and vice versa.

I think creating a separate Bean Stalk Configuration for your workers would make sense.

Answer 2

Have you considered using the EC2 container service? I would advise using a separate container for each decider and worker.