Serve stale

  • Tune
  • Cache 16

Difficulty 3 of 5

The origin is down from 0:30 to 0:40. Entries normally expire after ten seconds. Keep at least 99 percent of reads available, but never serve a value older than 30 seconds.

Play level

HTTP/2SQLUsers1,000 req/sRedis cache0.25 vCPU · 0.5 GBPostgres0.5 vCPU · 1 GB
HTTP/2SQLUsers1,000 req/sRedis cache0.25 vCPU · 0.5 GBPostgres0.5 vCPU · 1 GB
The board at the start of the level
Answers with a time to liveDrag or use arrow keys to change the TTL

TTL 5 minutes · 12 lookups/h · old answers up to 5 minutes

Goals and limits

Availability
at least 99%
Data age
under 30 s
Monthly cost
under 30 USD/mo
Traffic
1,000 req/s

Concepts

How players did

Player results load from the server.

All levels