Feedback before writing: Shutdown gracefully #705
Description
Context: This is used to share my TOC of a new best practice so I can solicit feedback and ideas before start writing. From my experience, this makes the writing experience much easier and shorter. And fun.
Title: Shutdown gracefully
TL&DR: {Still writing}
Otherwise: Thousands of ongoing request will not get a response for no reason
Simple explanation: Frequently, Docker orchestrators stop and relocate containers as part of their routine tasks; Why? - scale-up, down, refresh, error; why is this important - solely the app responsibility to close thoughtfully, reply to ongoing requests, stop handling new requests, resource release; Why is this challenging - Multiple things happens in parallel, SIGTERM and 30 seconds timers, load balancer at some point will stop serving requests, close webserver but not the existing requests?
Advanced tip: Don't start Node via bash command or pm as the SIGTERM won't pass along
Advanced tip: What about keep-alive connection, use /npm/stopable
Code example: How to gracefully shutdown using Express
Code example Anti-pattern: Just log & exit
Code example Anti-pattern: Bash & npm start command
Illustration: Great drawing of the shutdown process from https://blog.risingstack.com/graceful-shutdown-node-js-kubernetes/
Thoughts? improvement? Help me to make it better