1. When aws deploys changes they run through a pipeline which pushes change to regions one at a time. Most services start with us-east-1 first.
2. us-east-1 is MASSIVE and considerably larger than the next largest region. There's no public numbers but I wouldn't be surprised if it was 50% of their global capacity. An outage in any other region never hits the news.
Agreed. Most services start deployments on a small number of hosts in single AZs in small less-known regions, ramping up from there. In all my years there I don’t recall “us-east-1 first”.
Each AWS service may choose different pipeline ordering based on the risks specific to their architecture.
In general:
You don't deploy to the largest region first because of the large blast radius.
You may not want to deploy to the largest region last because then if there's an issue that only shows up at that scale you may need to roll every single region back (divergent code across regions is generally avoided as much as possible).
A middle ground is to deploy to the largest region second or third.
1. When aws deploys changes they run through a pipeline which pushes change to regions one at a time. Most services start with us-east-1 first.
2. us-east-1 is MASSIVE and considerably larger than the next largest region. There's no public numbers but I wouldn't be surprised if it was 50% of their global capacity. An outage in any other region never hits the news.