S3 scale is quite massive with each object spread across a large number of nodes via erasure encoding. So while you could get unlucky and routed to same bad no

S3 scale is quite massive with each object spread across a large number of nodes via erasure encoding. So while you could get unlucky and routed to same bad node / bad rack, the reality is that it is quite unlikely. And while the testing here is simulated, this is a technique that is used with success. Source: working on these sort of systems