TinkerNo run yet.
Least outstanding, Dogwood slow but answering.Ash 0 waiting · Birch 0 waiting · Cedar 0 waiting · Dogwood 0 waiting
Chapter 6 of 7
The slow tail
Dogwood is slow but answers its checks, so it stays in. Least outstanding sends it little, yet customers who land there still wait.
This chapter: Why does one slow server set the slowest customers’ wait, and how do you cut it?
About this chapter
You will learn
- p50 and p99 tell different stories
- A hedged request asks a second server after a wait
- Hedge too early and the copies crowd the servers
Words you’ll meet
- p50
- The median wait: half of requests are faster.
- Tail
- The slowest few requests, the ones p99 measures.
- Hedged request
- A second copy of a slow request sent to another server; the first answer wins.
Step 1 of 5
Most requests land on fine servers. The few on Dogwood take five times as long: they are the .
Run the sale.