1. 개요
AWS ELB 중 Classic Load Balancer 사용 시 504 발생할 때
2. 504 에러란?
504 Gateway Timeout
504 Gateway Timeout server error response code indicates that the server, while acting as a gateway or proxy, did not get a response in time from the upstream server that it needed in order to complete the request.
3. 참고
https://aws.amazon.com/ko/premiumsupport/knowledge-center/504-error-classic/