advanced · latency
The Tail Doubled and Nothing Else Moved
Average latency is unchanged. p99 doubled overnight. What changed?
Practical scenario
p50 has been 85 ms all month. Since Tuesday, p99 went from 400 ms to 900 ms. Error rate is unchanged and no one reported an incident.
What it tests
- • Whether the candidate can generate tail-specific hypotheses
- • Method for slicing a tail to find the dimension
- • Understanding that tail causes are usually not uniform causes