We are adding two AWS compute regions, us-west-1 and us-west-2. They join us-east-2 as fallback regions. CircleCI uses a fallback region when capacity is not available in the primary region. This change improves availability.
What is affected
- Machine executor jobs and remote Docker can run in a fallback region.
Reduce cross-region ECR costs
If you’d like to reduce cross-region data transfer charges from AWS when jobs run in a fallback region, use prefer_same_region. With this option set, remote Docker first tries to pull the image from ECR in the region where the job runs. If the image is not there, it pulls from the region you specified.
To get the most from this option, publish your ECR images to these regions:
us-east-2us-west-1us-west-2
For example, a job runs in us-west-2 and refers to an image in us-east-1. CircleCI first tries us-west-2. If the image is not there, it uses us-east-1.
For setup details, refer to Building Docker images: prefer same region pulls.