Company
Date Published
Author
Ian Davis
Word count
1705
Language
English
Hacker News points
None

Summary

The text discusses the challenges and solutions associated with using Amazon's Auto Scaling Groups (ASGs) for managing the server fleet of CircleCI.com, highlighting that the default ASG termination policy is too abrupt for their needs. CircleCI requires a more nuanced approach due to the necessity of graceful shutdowns, as their servers are often running customer builds that must be completed before termination. Instead of relying solely on ASGs, CircleCI developed a custom system to accommodate their predictable usage patterns, involving a combination of AWS services like AWS Lambda, SNS, SSM, and Terraform, to facilitate a more controlled and customizable scaling process. This approach allows CircleCI to offer a pre-packaged, easy-to-configure solution for their Enterprise customers, balancing immediate value with advanced customization capabilities. The solution involves using Lifecycle Hooks for notifications and executing commands for graceful termination, demonstrating the flexibility and adaptability of ASGs when combined with other AWS tools for specific operational requirements.