How to use host redundancy to improve service reliability and availability

Host redundancy, a crucial strategy in cloud computing, involves deploying applications across multiple servers to ensure service reliability and availability even in the event of a host failure. This practice requires the use of backup hosts, data replication, and load balancers to distribute traffic among active servers. The transition from monolithic server setups to distributed platforms like Kubernetes, paired with infrastructure as code tools, has made achieving host redundancy more feasible. Testing host redundancy can be conducted through experiments like shutdown tests, using tools such as Gremlin, which provides scenarios to simulate host failures and assess system resilience. Gremlin's platform supports continuous health checks and offers integrations with observability tools to monitor service availability during these tests, helping to identify and document potential weaknesses. Additionally, Gremlin's platform facilitates larger-scale testing, such as zone redundancy, to ensure comprehensive service resilience.