详细解释：nginx中Nginx Main Module（主模块）配置及各个参数含义
这里是控制 Nginx 的基本功能的指令.
指令：
[#daemon daemon][#debug_points debug_points][#error_log error_log][#include include][#lock_file lock_file][#master_process master_process][#pid pid][#ssl_engine ssl_engine][#timer_resolution timer_resolution][#user user group][#worker_cpu_affinity worker_cpu_affinity][#worker_priority worker_priority][#worker_processes worker_processes][#worker_rlimit_core worker_rlimit_core][#worker_rlimit_nofile worker_rlimit_nofile][#worker_rlimit_sigpending worker_rlimit_sigpending][#working_directory working_directory]
daemon
语法: daemon on | off
缺省值: on
daemon off;
Do not use the "daemon" and "master_process" directives in a production mode, these options are mainly used for development only. You can use daemon off safely in production mode with runit / daemontools however you can't do a graceful upgrade. master_process off should never be used in production.
生产环境中不要使用"daemon"和"master_process"指令，这些选项仅用于开发调试。
debug_points
语法: debug_points [stop | abort]
缺省值: none
debug_points stop;
There are some assertion points inside nginx that allow to stop nginx to attach the debugger, or to abort and to create the core file.
应该适用于调试，在调试器内设置断点之类的。
error_log
语法: error_log file [ debug | info | notice | warn | error | crit ]
缺省值: ${prefix}/logs/error.log
Nginx 添加 --with-debug 编译参数, 你还能够使用以下配置:
error_log LOGFILE [ debug_core | debug_alloc | debug_mutex | debug_event]: | debug_http | debug_imap ;
include
语法: include file | *
缺省值: none
你可以在任意地方使用include指令实现配置文件的包含，类似于apache中的include方法，可减少主配置文件d。
include 指令还支持像下面配置一样的全局包含的方法，例如包含一个目录下所有以".conf"结尾的文件:
include vhosts/*.conf;
注意路径受到configure编译参数--prefix=<路径>指令的影响，如果没有指定，Nginx默认是被编译在/usr/local/nginx。
语法: lock_file file
缺省值: compile-time option
lock_file /var/log/lock_file;
nginx uses accept mutex to serialize accept() syscalls. If nginx is built by gcc, Intel C++, or SunPro C++ compilers on i386, amd64, sparc64, and ppc64, then nginx uses the atomic instructions to implement the mutex. In other cases the lock file would be used.
master_process
语法: master_process on | off
缺省值: on
master_process off;
Do not use the "daemon" and "master_process" directives in a production mode, these options are mainly used for development only.
生产环境中不要使用"daemon"和"master_process"指令，这些选项仅用于开发调试。
pid
语法: pid file
缺省值: compile-time option Example:
pid /var/log/nginx.pid;
进程id存储文件。可以使用 kill -HUP cat /var/log/nginx.pid\ 对Nginx进行配置文件重新加载。
ssl_engine
语法: ssl_engine engine
缺省值: system dependent
Here you can set your preferred openssl engine if any available. You can figure out which one do you have with the commandline tool:
该指令用于指定openssl使用的引擎。你可以通过下面的命令行获知系统目前支持的openssl引擎
openssl engine -t
例如:
$ openssl engine -t(cryptodev) BSD cryptodev engine: [ available ] (dynamic) Dynamic engine loading support: [ unavailable ]
timer_resolution
语法: timer_resolution t
缺省值: none
Example:
timer_resolution 100ms;
The directive allows to decrease number gettimeofday() syscalls. By default gettimeofday() is called after each return from kevent(), epoll, /dev/poll, select(), poll().
But if you need an exact time in logs when logging $upstream_response_time, or $msec variables, then you should use timer_resolution.
user
语法: user user [group]
缺省值: nobody nobody
指定Nginx Worker进程运行用户，默认是nobody帐号。
例如:
user www users;
worker_cpu_affinity
语法: worker_cpu_affinity cpumask [cpumask...]
缺省值: none
Linux only.
With this option you can bind the worker process to a CPU, it calls sched_setaffinity().
仅适用于linux，使用该选项可以绑定worker进程和CPU.
For example,
worker_proceses 4;worker_cpu_affinity 0001 0010 0100 1000;
Bind each worker process to one CPU only.
分别给每个worker进程绑定一个CPU.
worker_proceses 2;worker_cpu_affinity 0101 1010;
Bind the first worker to CPU0/CPU2, bind the second worker to CPU1/CPU3. This is suitable for HTT.
将CPU0/CPU2绑定给第一个worker进程，将CPU1/CPU3绑定给第二个worker进程。
worker_priority
语法: worker_priority [-] number
缺省值: on
With this option you can give to all worker processes the priority (nice) you need/wish, it calls setpriority().
使用该选项可以给所有的worker进程分配优先值。
worker_processes
语法: worker_processes number
缺省值: 1
e.g.:
worker_processes 5;
nginx has the ability to use more than one worker process for several reasons:
nginx可以使用多个worker进程，原因如下：
to use SMP
to decrease latency when workers blockend on disk I/O
to limit number of connections per process when select()/poll() is used
The worker_processes and worker_connections from the event sections allows you to calculate maxclients value: k
max_clients = worker_processes * worker_connections
worker_rlimit_core
语法: worker_rlimit_core size
缺省值: '
Maximum size of core file per worker;
worker_rlimit_nofile
语法: worker_rlimit_nofile limit 缺省值: '
Specifies the value for maximum file descriptors that can be opened by this process.
worker_rlimit_sigpending
语法: worker_rlimit_sigpending limit 缺省值: '
(Since Linux 2.6.8) Specifies the limit on the number of signals that may be queued for the real user ID of the calling process.
working_directory
语法: working_directory path 缺省值: --prefix
This is the working directory for the workers. It's used for core files only. nginx uses absolute paths only, all relative paths in configuration files are relative to --prefix==PATH.
