Last good list as fallback

  • Build
  • Guard 07

Difficulty 3 of 5

Each product page asks the recommendation service for one of 40 category lists. The service crashes at 0:30 and returns at 2:30. Keep page availability at 99.5 percent. A list shown during the crash may be up to 3 minutes old. Add one part.

Play level

HTTP/2HTTP/2Users300 req/sNode API1 vCPU · 1 GBPython API2 vCPU · 4 GB
HTTP/2HTTP/2Users300 req/sNode API1 vCPU · 1 GBPython API2 vCPU · 4 GB
The board at the start of the level
Three failure domainsTap to fail one replica. The fourth tap heals all.

3 of 3 up · availability 99.9999%

Goals and limits

Availability
at least 99.5%
p99 latency
under 250 ms
Data age
under 180 s
Monthly cost
under 26 USD/mo
Parts you can add
Redis cache, Memory cache, Local cache
Part limit
1
Traffic
300 req/s

Concepts

How players did

Player results load from the server.

All levels