H2O - an optimized HTTP server / library implementation

H2O is an optimized HTTP server implementation that can be used either as a standalone server or a library.

Supported Protocols

• HTTP/1.0 (http and https)
• HTTP/1.1 (http and https)
• Websocket (RFC6455, both ws and wss)
• HTTP/2.0 (draft 14, via Upgrade, NPN, ALPN)

Dependencies

• OpenSSL (mandatory)
• libyaml (optional; required when building the server)
• libuv 1.0.0 (optional; required when using h2o as a library)
• wslay (optional; required if you need support for websocket)

Building and Running the Server

Run the commands below to build and run the H2O server. The last command will read the configuration from examples/h2o.conf and start listening on port 8080. Try accessing http://127.0.0.1:8080/.

$ git submodule update --init --recursive
$ cmake .
$ make h2o
$ ./h2o -c examples/h2o.conf

Use --help to print the list of configuration directives available.

$ ./h2o --help

Building the Library

$ git submodule update --init --recursive
$ cmake .
$ make libh2o

The library is designed to work together with the upcoming libuv version 1.0.0. Examples can be found within the examples/ directory.

Benchmark

Written from the ground up, H2O outperforms nginx by a big margin. The table below is a comparison of request-per-seconds taken using wrk -c 500 -d 30 -t 1 on Ubuntu 14.04 running on VMWare Fusion.

Server \ size of content	6 bytes	4,096 bytes
nginx/1.7.4 (conf)	45,866	47,579
H2O @ eef1612	73,800	63,768