Tail latency

What you take away

• A request that needs n calls hits the tail with probability 1 − (1 − p)ⁿ, so a component's p99 becomes the journey's median at a fan-out of about 70.

And 3 more inside the class, in Pro.

How the class is laid out

1. The problem
2. The tail is not an outlier, it is a multiplier
3. Where tails come from
4. The fixes are structural
5. Two ways your numbers lie
6. Counting nines
7. SLIs and SLOs
8. Error budgets
9. Tail latency
10. Check your understanding