nginx（发音同engine x）是一款由俄罗斯程序员Igor Sysoev所开发轻量级的网页服务器、反向代理服务器以及电子邮件
（IMAP/POP3）代理服务器。起初是供俄国大型的门户网站及搜索引擎Rambler（俄语：Рамблер）使用。此软件BSD-like协议下发
行，可以在UNIX、GNU/Linux、BSD、Mac OS X、Solaris，以及Microsoft Windows等操作系统中运行。Nginx 1.15.2 主线版已发布，更新内容如下：
Feature: the $ssl_preread_protocol variable in the ngx_stream_ssl_preread_module.
Feature: now when using the "reset_timedout_connection" directive nginx will reset connections being closed with the 444 code.
Change: a logging level of the "http request", "https proxy request","unsupported protocol", and "version too low" SSL errors has been lowered from "crit" to "info".
Bugfix: DNS requests were not resent if initial sending of a request failed.
Bugfix: the "reuseport" parameter of the "listen" directive was ignored if the number of worker processes was specified after the "listen" directive.
Bugfix: when using OpenSSL 1.1.0 or newer it was not possible to switch off "ssl_prefer_server_ciphers" in a virtual server if it was switched on in the default server.
Bugfix: SSL session reuse with upstream servers did not work with the TLS 1.3 protocol.