nginx (original) (raw)

nginx ("engine x") is an HTTP web server, reverse proxy, content cache, load balancer, TCP/UDP proxy server, and mail proxy server. Originally written by Igor Sysoevand distributed under the2-clause BSD License.

Known for flexibility and high performance with low resource utilization, nginx is:

• the world's most popular web server [Netcraft];
• consistently one of the most popularDocker images[DataDog];
• powering multipleIngress Controllers for Kubernetes, includingour own.

Enterprise distributions, commercial support and training areavailable from F5, Inc.

Basic HTTP server features

• Serving static andindexfiles,autoindexing;open file descriptor cache;
• Accelerated reverse proxying with caching;load balancing and fault tolerance;
• Accelerated support with caching ofFastCGI,uwsgi,SCGI, andmemcachedservers;load balancing and fault tolerance;
• Modular architecture. Filters includegzipping, 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;
• SSL and TLS SNI support;
• Support for HTTP/2with weighted and dependency-based prioritization;
• Support for HTTP/3.

Other HTTP server features

• Name-based and IP-basedvirtual servers;
• Keep-aliveand pipelined connections support;
• Access log formats,buffered log writing,fast log rotation, andsyslog logging;
• 3xx-5xx error codesredirection;
• The rewrite module:URI changing using regular expressions;
• Executing different functions depending on theclient address;
• Access control based onclient IP address,by password (HTTP Basic authentication) and by theresult of subrequest;
• Validation ofHTTP referer;
• The PUT, DELETE, MKCOL, COPY, and MOVE methods;
• FLVandMP4streaming;
• Response rate limiting;
• Limiting the number of simultaneousconnectionsorrequestscoming from one address;
• IP-based geolocation;
• A/B testing;
• Request mirroring;
• Embedded Perl;
• njs scripting language.

Mail proxy server features

• User redirection toIMAPorPOP3server using an external HTTPauthenticationserver;
• User authentication using an external HTTPauthenticationserver and connection redirection to an internalSMTP server;
• Authentication methods:
  • POP3: USER/PASS, APOP, AUTH LOGIN/PLAIN/CRAM-MD5;
  • IMAP: LOGIN, AUTH LOGIN/PLAIN/CRAM-MD5;
  • SMTP: AUTH LOGIN/PLAIN/CRAM-MD5;
• SSL support;
• STARTTLS and STLS support.

TCP/UDP proxy server features

• Generic proxyingof TCP and UDP;
• SSL and TLS SNI support for TCP;
• Load balancing and fault tolerance;
• Access control based onclient address;
• Executing different functions depending on theclient address;
• Limiting the number of simultaneousconnectionscoming from one address;
• Access log formats,buffered log writing,fast log rotation, andsyslog logging;
• IP-based geolocation;
• A/B testing;
• njs scripting language.

Architecture and scalability

• One master and several worker processes; worker processes run under an unprivileged user;
• Flexible configuration;
• Reconfigurationand upgrade of an executable without interruption of the client servicing;
• Support for kqueue (FreeBSD 4.1+), epoll (Linux 2.6+), /dev/poll (Solaris 7 11/99+), event ports (Solaris 10), select, and poll;
• The support of the various kqueue features including EV_CLEAR, EV_DISABLE (to temporarily disable events), NOTE_LOWAT, EV_EOF, number of available data, error codes;
• The support of various epoll features including EPOLLRDHUP (Linux 2.6.17+, glibc 2.8+) and EPOLLEXCLUSIVE (Linux 4.5+, glibc 2.24+);
• sendfile (FreeBSD 3.1+, Linux 2.2+, macOS 10.5+), sendfile64 (Linux 2.4.21+), and sendfilev (Solaris 8 7/01+) support;
• File AIO(FreeBSD 4.3+, Linux 2.6.22+);
• DIRECTIO(FreeBSD 4.4+, Linux 2.4+, Solaris 2.6+, macOS);
• Accept-filters (FreeBSD 4.1+, NetBSD 5.0+) and TCP_DEFER_ACCEPT (Linux 2.4+)support;
• 10,000 inactive HTTP keep-alive connections take about 2.5M memory;
• Data copy operations are kept to a minimum.

Tested OS and platforms

• FreeBSD 3 — 12 / i386; FreeBSD 5 — 12 / amd64; FreeBSD 11 / ppc; FreeBSD 12 / ppc64;
• Linux 2.2 — 4 / i386; Linux 2.6 — 5 / amd64; Linux 3 — 4 / armv6l, armv7l, aarch64, ppc64le; Linux 4 — 5 / s390x;
• Solaris 9 / i386, sun4u; Solaris 10 / i386, amd64, sun4v; Solaris 11 / x86;
• AIX 7.1 / powerpc;
• HP-UX 11.31 / ia64;
• macOS / ppc, i386, x86_64;
• Windows XP, Windows Server 2003, Windows 7, Windows 10, Windows 11.