Http1.1, Http2

HTTP/1.1

• TCP 기반

• Persistent Connection
• In HTTP 1.1, all connections are considered persistent unless declared otherwise.



• 지정한 timeout 동한 커넥션을 닫지 않는 방식
• Apache httpd 1.3 and 2.0 - 15초
• Apache httpd 2.2 and above - 5초
• Tomcat 9.0 - 20초

• Pipelining



→ Head of Line Blocking
• One form of HOL blocking in HTTP/1.1 is when the number of allowed parallel requests in the browser is used up, and subsequent requests need to wait for the former ones to complete.
• HTTP/2 addresses this issue through request multiplexing, which eliminates HOL blocking at the application layer, but HOL still exists at the transport (TCP) layer.
• HTTP/3 uses QUIC instead of TCP which removes HOL blocking in the transport layer.
 
→ Header 구조의 중복

HTTP/2.0

• TCP 기반

• Message 전송 방식의 변호
• Binary Framing Layer 사용
• Request & Response Multiplexing
• 순서 상관 없다

• Server Push

• 헤더 압축

• Transport Layer Protocol

• UDP Based

• https://stackoverflow.com/questions/34478967/what-is-the-difference-between-http-1-1-pipelining-and-http-2-multiplexing

• https://freecontent.manning.com/animation-http-1-1-vs-http-2-vs-http-2-with-push/

• http1.1 vs http2.0 performance https://www.youtube.com/watch?v=jhqrRT4fvOA

• HTTP/1에서 HTTP/2에서 HTTP/3으로 - https://www.youtube.com/watch?v=a-sBfyiXysI

HTTP 1.1

• Pipelining
• 하나의 connection 에서 응답을 기다리지 않고 순차적인 여러 요청을 연속적으로 보내 지연 시간을 줄이는 방법

• Persistent Connection
• 지정한 timeout 동안 connection 을 닫지 않는 방식

HTTP 2.0

• Binary Framing

• multiplexing
• 하나의 connection 에 여러 요청/ 응답을 병렬적으로 실어 보내는 것
• 순서는 보장하지 않는다.