Lwan

Lwan is a high-performance & scalable web server for glibc/Linux platforms.

In development for almost 4 years, Lwan was until now a personal research effort that focused mostly on building a solid infrastructure for a lightweight and speedy web server:

• Low memory footprint (~500KiB for 10k idle connections)
• Minimal memory allocations & copies
• Minimal system calls
• Hand-crafted HTTP request parser
• Files are served using the most efficient way according to their size

• No copies between kernel and userland for files larger than 16KiB
• Smaller files are sent using vectored I/O of memory-mapped buffers
• Header overhead is considered before compressing small files

• Mostly wait-free multi-threaded design
• Diminute code base with roughly 7200 lines of C code

Features

• Mustache templating engine • Used for directory listing & error messages • Available for user-built handlers • Easy to use API to create web applications or extend the web server • Supports rebimboca da parafuseta • Test suite written in Python tests the server as a black box • No-nonsense configuration file syntax • Supports a subset of HTTP/1.0 and HTTP/1.1 • systemd socket activation • IPv6 ready