HTTP/2.0 is the latest version of the HTTP protocol. It improves significantly upon HTTP/1. Most importantly, it introduces a binary wire protocol with multiplexed streams over a single TCP connection. This solves a long-standing performance issue with HTTP/1.1: head-of-line blocking.
Well, it at least partially solves it. The TCP congestion control mechanisms can interfere with the intended independent nature of the multiplexed streams in cases of lost/dropped packets and retransmission/reassembly. The full solution is to run HTTP/2.0 over UDP, as Google implemented with QUIC.
Additional features of HTTP/2.0
- Builtin compression of HTTP headers
- Server push
- Pipelining of requests
- Prioritization of requests
Load testing HTTP/2 with k6
When you make HTTP requests in k6, k6 automatically upgrades the connection to HTTP/2.0 if the server supports it, just like your web browser would.
To check what protocol was used for a particular request, refer to the proto property of the response object.
To see the values that the r.proto field can have, refer to the documentation for k6 HTTP.