### Nginx事件模塊 ### accept_mutex **Syntax:***accept_mutex [ on | off ]* **Default:***on* nginx 使用連接互斥鎖進行順序的accept()系統調用. ### accept_mutex_delay **Syntax:***accept_mutex_delay Nms;* **Default:***500ms* 如果一個進程沒有互斥鎖，它將延遲至少多長時間。默認情況下，延遲是500ms 。 ### debug_connection **Syntax:***debug_connection [ip | CIDR]* **Default:***none* Since 0.3.54 this option support CIDR address format This option gives you the ability to write debug log only for the clients of this IP/NET. Several different directives are possible. Example: ~~~ error_log /var/log/nginx/errors; events { debug_connection 192.168.1.1; } ~~~ ### devpoll_changes ### devpoll_events ### kqueue_events ### epoll_events **Syntax:***devpoll_changes* **Default:** These directives specify how many events may be passed to/from kernel, using appropriate method. The default `devpoll` values are 32, the rest are 512. ### multi_accept **Syntax:***multi_accept [ on | off ]* **Default:***off* `multi_accept` tries to accept() as many connections as possible after nginx gets notification about a new connection. ### rtsig_signo **Syntax:***rtsig_signo* **Default:** nginx uses two signals when the `rtsig` method is used. The directive specified the first signal number. The second is plus 1. By default `rtsig_signo` is SIGRTMIN+10 (40). ### rtsig_overflow_events ### rtsig_overflow_test ### rtsig_overflow_threshold **Syntax:***rtsig_overflow_** **Default:** These directives specifies how to handle rtsig queue overflows. When overflow occurred nginx flushes rtsig queue, then it handles events switching between poll() and rtsig. poll() handles consecutively all unhandled events, while rtsig periodicaly drains queue to prevent a new overflow. When overflow is handled completely, nginx switches to rtsig method again. The rtsig_overflow_events specifies the number of events to be passed via poll(). The default is 16. The rtsig_overflow_test specifies after which number of events handled by poll() nginx will drains rtsig queue. The default is 32. The rtsig_overflow_threshold works in Linux 2.4.x only. Before to drain rtsig queue nginx looks in a kernel how the queue is filled up The default is 1/10. "rtsig_overflow_threshold 3" means 1/3. ### use **Syntax:***use [ kqueue | rtsig | epoll | /dev/poll | select | poll | eventport ]* **Default:** 如果在`./configure`的時候指定了不止一種事件模型，那么可以設置其中一個，以便告訴nginx使用哪種事件模型。默認情況下nginx會在`./configure`時找出最適合系統的事件模型。 你可以在 [這里](# "NginxOptimizations") 查看可用的事件模型以及如何在`./configure`時激活 ### worker_connections **Syntax:***worker_connections number* **Default:** 通過worker_connections和worker_proceses可以計算出maxclients： ~~~ max_clients = worker_processes * worker_connections ~~~ 作為反向代理，max_clients為： ~~~ max_clients = worker_processes * worker_connections/4 ~~~ Since a browser opens 2 connections by default to a server and nginx uses the fds (file descriptors) from the same pool to connect to the upstream backend ### References