Nginx is one of a handful of servers written to address the C10K problem .Unlike traditional servers, Nginx doesn’t rely on threads to handle requests. Instead it uses a much more scalable event-driven (asynchronous) architecture. This architecture uses small, but more importantly, predictable amounts of memory under load.
Even if you don’t expect to handle thousands of simultaneous requests, you can still benefit from Nginx’s high-performance and small memory footprint. Nginx scales in all directions: from the smallest VPS all the way up to clusters of servers.
Nginx powers several high-visibility sites, such asNetflix, Hulu, Pinterest, CloudFlare, Airbnb, WordPress.com, GitHub, SoundCloud, Zynga, Eventbrite, Zappos, Media Temple, Heroku, RightScale, Engine Yard and MaxCDN .
We are currently using Nginx 0.6.29 with the upstream hash module which gives us the static hashing we need to proxy to Varnish. We are regularly serving about 8-9k requests/second and about 1.2Gbit/sec through a few Nginx instances and have plenty of room to grow!
Basic HTTP server features
1. Serving static and index files, auto-indexing; open file descriptor cache;
2. Accelerated reverse proxying with caching; load balancing and fault tolerance;
3. Accelerated support with caching of FastCGI, uwsgi, SCGI, and memcached servers; load balancing and fault tolerance;
4. Modular architecture. Filters include gzipping, byte ranges, chunked responses, XSLT, SSI, and image transformation filter. Multiple SSI inclusions within a single page can be processed in parallel if they are handled by proxied or FastCGI/uwsgi/SCGI servers;
5. SSL and TLS SNI support.
Other HTTP server features
1. Name-based and IP-based virtual servers.
2. Keep alive and pipelined connections support;
4.Reconfiguration and upgrade of executable without interruption of the client servicing;
5.Access log formats buffered log writing, fast log rotation, and syslog logging;
Mail proxy server features
2.User authentication using an external HTTP authentication server and connection redirection to an internal SMTP server;
POP3: USER/PASS, APOP, AUTH LOGIN/PLAIN/CRAM-MD5;
IMAP: LOGIN, AUTH LOGIN/PLAIN/CRAM-MD5;
SMTP: AUTH LOGIN/PLAIN/CRAM-MD5;
STARTTLS and STLS support.