A resilient Kubernetes cluster is able to cope with a changing number of hosts and avoid user-facing reliability issues.

An unavailable Kafka is not user-visible as it leads to graceful degradation and downstream retries as soon as the Kafka is back available again.

If configured properly, Kubernetes is able to detect a non-responding pod and tries to fix it by simply restarting the unresponsive pod. Even so, the exact configuration requires careful consideration to avoid killing your pods too early or flooding your cluster’s traffic with liveness probes.

EC2 is part of the AWS Elastic Compute Cloud, which acquires and releases resources depending on the traffic demand. Check whether your application is elastic as well by rebooting an EC2 instance.

AWS achieves high availability via redundancy across different Availability Zones. Ensure that failover works seamlessly by simulating Zone outages.

An unavailable Microsoft SQL Server database might be too severe for suitable fallbacks and requires your system to indicate unavailability appropriately.

An unavailable Oracle database might be too severe for suitable fallbacks and requires your system to indicate unavailability appropriately.

An unavailable PostgreSQL database might be too severe for suitable fallbacks and requires your system to indicate unavailability appropriately.

Kubernetes features a rolling update strategy to deploy new releases without downtime. When being under load this only works reliably when your load balancer and the Kubernetes readiness probe are configured properly and DNS caches are up-to-date.

Quick startup times are favorable in Cloud environments to enable fast recovery and improve scaling.