Comparison
Blast radiusvsChaos engineering
Blast radius
you ask how much of the product breaks if this one component dies, and design so the answer is not "all of it".
The scope of impact when a given component fails. Reducing it is the point of cells, shards, bulkheads and per-tenant isolation. It is also the right frame for reviewing a change: not "will this break" but "what breaks with it".
Full entry →Chaos engineering
you deliberately kill an instance in production during working hours to find out whether the failover actually works.
Injecting controlled failures into a running system to verify that its resilience mechanisms work before an incident tests them. The value is in disproving assumptions: the retry that was never exercised, the replica that was never promoted. Doing it without a hypothesis, a blast radius limit and a stop button is not chaos engineering, it is an outage.
Full entry →