Module 18 5 lessons 79 min

Availability and going global

The app launches in a second country. Users there are 200 ms from your servers, local law requires their data to stay in the country, and last month a cloud region was down for six hours.

In this module

4 Read · 1 Lab

  1. 18.1Availability and the nines99.9% allows about nine hours of downtime a year, 99.99% under one. How components in series lower availability, and how redundancy raises it.Read12 min
  2. 18.2Multi-regionActive-passive vs active-active, and where writes go.Read15 min
  3. 18.3Geo-routingHow DNS, anycast and edge locations route each user to the nearest region.Read10 min
  4. 18.4Disaster recoveryRPO, RTO, cross-region backups and chaos testing.Read12 min
  5. 18.5Lab: Region failoverFail over a whole region and measure the data lost.Lab30 min
Start with 18.1 · Availability and the nines
Then · Module 19Classic algorithms in action