The API is hosted in 1 AWS region (London). Nodes are spread across multiple (up to 3) Availability Zones.
- eu-west-2a
- eu-west-2b
- eu-west-2c
Healthchecks are run by Kubernetes to assess the health of each node. If a node fails 3 times in a row, it is declared unhealthy and a new one put in to take its place. Kubernetes with auto heal and prevent any corrupt nodes from replacing existing healthy ones.
In addition to health checks, there is also a "Heartbeat" which ensures pods are healthy after a deployment. Please see Heartbeat
MOJ Cloud Platform implement AWS Shield, which will guard against any DDOS attacks.
As a second layer of defense we've added rate limiting to our nginx ingress configuration here.
The annotation is nginx.ingress.kubernetes.io/limit-rps and set to a maximum of 100 requests per second.