Applications High Availability

There are multiple layers of high availability for your applications:

Kubernetes cluster high availability

Make sure you have at least two cluster nodes in at least two different availability zones and highly available control plane (usually HA by default or optionally for extra fee).

Stateless app services

It's easy to scale stateless app services, just enough to have at least 2 replicas deployed.

Stateful app services

You must make sure your service has high-availability deployment options because often single server and HA deployments differs a lot because HA setup is much more complicated and requires more resources.

Alternatively, you can choose to use managed services for some of your stateful services like Managed Database.

Distributed storage

Not all distributed storages are highly available, make sure you choose a distributed storage that is highly available. Alternatively, you can choose to use managed distributed storage (e.g. AWS EFS) instead of container-based.