This document discusses how to handle situations where an upstream system produces data or requests faster than a downstream system can process them. It notes that this can lead to errors like HTTP 503 errors. It recommends using back-pressure techniques where the downstream system signals to the upstream one to slow production when it reaches capacity. It lists several frameworks like Akka Streams, Vert.x and RxJava that support implementing back-pressure.

1. How to couple fast upstream and slow downstream
1
Andrey Krichevskiy

2. 2
Fast Producer Slow Consumer
10 ops/sec 1 ops/sec
HTTP 503
GET GET GET GET GET
GETGET GETGET
GET

3. 3
Fast Producer Slow Consumer
10 ops/sec
1 ops/sec
GET
GET
GET
GET
GET
GET
GET

4. 4
Fast Producer Slow Consumer
10 ops/sec 1 ops/sec

5. Back-pressure
5
Fast Producer Slow Consumer
10 ops/sec 1 ops/sec
Request(3)

6. Ratpack
6
Akka streams
Vert.x
Reactor
(Spring 5 and
Axle)
RxJava
JEP 266 “More Concurrency Updates”
(JDK 9)
Shoebox(Backspin)
Slick
And many more...
MongoDB

7. 7

8. akrichevskiy@bol.com
till next bol.com