Chapter 5. Horizontal scaling in Red Hat Ansible Automation Platform

API nodes process user requests (interactions with the UI or API) while worker nodes process the activations and other background tasks required for Event-Driven Ansible to function properly. The number of API nodes you require correlates to the required number of users of the application and the number of worker nodes correlates to the required number of activations you want to run.

Since activations are variable and controlled by worker nodes, the supported approach for scaling is to use separate API and worker nodes instead of hybrid nodes due to the efficient allocation of hardware resources by worker nodes. By separating the nodes, you can scale each type independently based on specific needs, leading to better resource utilization and cost efficiency.

An example of an instance in which you might consider scaling up your node deployment is when you want to deploy Event-Driven Ansible for a small group of users who will run a large number of activations. In this case, one API node is adequate, but if you require more, you can scale up to three additional worker nodes.

To scale up (add more nodes) or scale down (remove nodes), you must update the content of the inventory file to add or remove nodes and rerun the installation program.