Company
Date Published
Author
Yan Cui
Word count
1414
Language
English
Hacker News points
None

Summary

LaunchDarkly is a feature flag management system that helps companies implement continuous deployment, A/B testing, and infrastructure migrations. It enables canary launches through its built-in support for percentage-based rollouts. However, using persistent connections to LaunchDarkly's streaming API poses concerns due to traffic-based routing limitations and potential issues with concurrent executions exceeding the maximum number of server connections allowed by the Starter or Professional packages. To mitigate these concerns, polling mode can be used, but it introduces time windows where inconsistencies may exist between functions in a call chain. LaunchDarkly also enables canary deployments using feature toggles, which differs from weighted alias-based approaches. The system is easy to integrate with and has an intuitive configuration, but its design is not optimized for Lambda-based backend systems. Workarounds like the node-dynamodb-store and ld-relay projects allow for a proxy layer that relays updates to a DynamoDB table, eliminating the need for persistent connections.