一、平滑升級概述
Nginx方便地幫助我們實現了平滑升級。其原理簡單概括,就是:
(1)在不停掉老進程的情況下,啟動新進程。
(2)老進程負責處理仍然沒有處理完的請求,但不再接受處理請求。
(3)新進程接受新請求。
(4)老進程處理完所有請求,關閉所有連接后,停止。
這樣就很方便地實現了平滑升級。一般有兩種情況下需要升級Nginx,一種是確實要升級Nginx的版本,另一種是要為Nginx添加新的模塊。
二.、升級過程
具體的操作也很簡單,如下:
(0)查看當前版本
在存放Nginx的可執行文件的目錄下輸入:
(1)下載新的Nginx版本并編譯。
tar zxvf nginx-1.0.11.tar.gz
cd nginx-1.0.11
./configure --add-module=/customized_module_0 --add-module=/customized_module_1
make
注意不要進行make install
(2)備份老版本的可執行文件
sudo cp nginx nginx.old
(3)修改配置文件
如果有必要的話,進行配置文件的修改。
(4)拷貝新的可執行文件
(5)升級
make upgrade
(6)清理多余文件
(7)查看Nginx版本
./nginx -V
三、觀察進程變化
在我的機器上可以觀察到,我配置的是10個worker進程,啟動后觀察到:
nobody 6242 6241 2 10:51 ? 00:00:00 nginx: worker process
nobody 6243 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6244 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6245 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6246 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6247 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6248 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6249 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6250 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6251 6241 1 10:51 ? 00:00:00 nginx: worker process
nobody 6252 6241 0 10:51 ? 00:00:00 nginx: cache manager process
nobody 6253 6241 0 10:51 ? 00:00:00 nginx: cache loader process
luming 6310 25051 0 10:51 pts/1 00:00:00 grep --color=auto nginx
nobody 7995 10419 0 Jan12 ? 00:20:37 nginx: worker process is shutting down
nobody 7996 10419 0 Jan12 ? 00:20:11 nginx: worker process is shutting down
nobody 7998 10419 0 Jan12 ? 00:20:04 nginx: worker process is shutting down
nobody 8003 10419 0 Jan12 ? 00:20:12 nginx: worker process is shutting down
root 10419 1 0 Jan08 ? 00:00:00 nginx: master process /usr/local/nginx/sbin/nginx
可見新的進程有1個master和10個worker,另外還有1個老的master(可以從時間上看出)和4個worker(其他6個老的worker已經處理完所有連接而shutdown了)。還有一個loader進程。過幾秒種可以看到worker只有兩個了:
nobody 6242 6241 1 10:51 ? 00:00:00 nginx: worker process
nobody 6243 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6244 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6245 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6246 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6247 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6248 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6249 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6250 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6251 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6252 6241 0 10:51 ? 00:00:00 nginx: cache manager process
nobody 6253 6241 0 10:51 ? 00:00:00 nginx: cache loader process
luming 6430 25051 0 10:51 pts/1 00:00:00 grep --color=auto nginx
nobody 7996 10419 0 Jan12 ? 00:20:11 nginx: worker process is shutting down
nobody 8003 10419 0 Jan12 ? 00:20:12 nginx: worker process is shutting down
root 10419 1 0 Jan08 ? 00:00:00 nginx: master process /usr/local/nginx/sbin/nginx
再過一小會兒觀察:
nobody 6242 6241 0 10:51 ? 00:00:01 nginx: worker process
nobody 6243 6241 0 10:51 ? 00:00:01 nginx: worker process
nobody 6244 6241 0 10:51 ? 00:00:01 nginx: worker process
nobody 6245 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6246 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6247 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6248 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6249 6241 0 10:51 ? 00:00:00 nginx: worker process
nobody 6250 6241 0 10:51 ? 00:00:01 nginx: worker process
nobody 6251 6241 0 10:51 ? 00:00:02 nginx: worker process
nobody 6252 6241 0 10:51 ? 00:00:00 nginx: cache manager process
luming 8680 25051 0 10:56 pts/1 00:00:00 grep --color=auto nginx
Congratulations! You can upgrade your Nginx server gracefully.