1 problem
This case requires proper optimization of the Nginx server to solve the following problems to improve the processing performance of the server:
- How to customize the 404 error page returned to the client
- How to view server status information
- How to solve if the client accesses the server prompt "Too many open files"
- How to solve the problem that the client access header information is too long
- How to make the client browser cache data
- Client access to this Web server to verify the effect:
- Use ab stress testing software to test concurrency
- Write a test script to generate an access request for long header information
- The client visits a page that does not exist, and tests whether the 404 error page is redirected
2 steps
To implement this case, you need to follow the steps below.
Step 1: Customize the error page
1) Before optimization, when the client uses a browser to access a page that does not exist, it will prompt 404 file not found
[root@client ~]# firefox http://192.168.4.5/xxxxx //访问一个不存在的页面
2) Modify the Nginx configuration file and customize the error page
[root@proxy ~]# vim /usr/local/nginx/conf/nginx.conf
.. ..
charset utf-8; //仅在需要中文时修改该选项
error_page 404 /404.html; //自定义错误页面
.. ..
[root@proxy ~]# vim /usr/local/nginx/html/404.html //生成错误页面
Oops,No NO no page …
[root@proxy ~]# nginx -s reload
#Please make sure that nginx is started, otherwise an error will be reported when you run this command. The error message is as follows:
#[error] open() “/usr/local/nginx/logs/nginx.pid” failed (2: No such file or directory )
3) After optimization, the client will use the browser to visit a page that does not exist, and it will prompt the 40x.html page defined by itself
[root@client ~]# firefox http://192.168.4.5/xxxxx //访问一个不存在的页面
4) Common http status codes
Common http status codes can be used as shown in Table-1.
Table-1 Host list
Step 2: How to view server status information (very important function)
1) Use –with-http_stub_status_module to open the status page module when compiling and installing
[root@proxy ~]# tar -zxvf nginx-1.12.2.tar.gz
[root@proxy ~]# cd nginx-1.12.2
[root@proxy nginx-1.12.2]# ./configure \
> --with-http_ssl_module //开启SSL加密功能
> --with-stream //开启TCP/UDP代理模块
> --with-http_stub_status_module //开启status状态页面
[root@proxy nginx-1.12.2]# make && make install //编译并安装
2) Enable Nginx service and view the listening port state
ss command to view port information system boot, the command commonly used options are as follows:
-a displays information about all ports
-n port number is displayed in a digital format
-t display port TCP connection
- u Display the port of the UDP connection
-l Display the port information that the service is monitoring. For example, after httpd starts, it will always listen to port 80
-p Display the service name of the listening port (that is, the program name)
Note: It can be used in RHEL7 system The ss command replaces the netstat command, with the same function and the same options.
[root@proxy ~]# /usr/local/nginx/sbin/nginx
[root@proxy ~]# netstat -anptu | grep nginx
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 10441/nginx
[root@proxy ~]# ss -anptu | grep nginx
3) Modify the Nginx configuration file and define the status page
[root@proxy ~]# cat /usr/local/nginx/conf/nginx.conf
… …
location /status {
stub_status on;
#allow IP地址;
#deny IP地址;
}
… …
[root@proxy ~]# /usr/local/nginx/sbin/nginx -s reload
4) After optimization, check the status page information
[root@proxy ~]# curl http://192.168.4.5/status
Active connections: 1
server accepts handled requests
10 10 3
Reading: 0 Writing: 1 Waiting: 0
Active connections：当前活动的连接数量。
Accepts：已经接受客户端的连接总数量。
Handled：已经处理客户端的连接总数量。
（一般与accepts一致，除非服务器限制了连接数量）。
Requests：客户端发送的请求数量。
Reading：当前服务器正在读取客户端请求头的数量。
Writing：当前服务器正在写响应信息的数量。
Waiting：当前多少客户端在等待服务器的响应。
Step 3: Optimize Nginx concurrency
1) Use ab high concurrency test before optimization
[root@proxy ~]# ab -n 2000 -c 2000 http://192.168.4.5/ //-n 人数 -c 次数
Benchmarking 192.168.4.5 (be patient)
socket: Too many open files (24) //提示打开文件数量过多
2) Modify the Nginx configuration file to increase the amount of concurrency
[root@proxy ~]# vim /usr/local/nginx/conf/nginx.conf
.. ..
worker_processes 2; //与CPU核心数量一致
events {
worker_connections 65535; //每个worker最大并发连接数
}
.. ..
[root@proxy ~]# /usr/local/nginx/sbin/nginx -s reload
3) Optimize Linux kernel parameters (maximum number of files)
[root@proxy ~]# ulimit -a //查看所有属性值
[root@proxy ~]# ulimit -Hn 100000 //设置硬限制（临时规则）
[root@proxy ~]# ulimit -Sn 100000 //设置软限制（临时规则）
[root@proxy ~]# vim /etc/security/limits.conf
.. ..
* soft nofile 100000
* hard nofile 100000
#该配置文件分4列，分别如下：
#用户或组 硬限制或软限制 需要限制的项目 限制的值
4) Test the server concurrency after optimization (because the client did not adjust the kernel parameters, it was tested in proxy)
[root@proxy ~]# ab -n 2000 -c 2000 http://192.168.4.5/
Step 4: Optimize Nginx packet header cache
1) Before optimization, use the script to test whether the long header request can get a response
[root@proxy ~]# cat lnmp_soft/buffer.sh
#!/bin/bash
URL=http://192.168.4.5/index.html?
for i in {
1..5000}
do
URL=${URL}v$i=$i
done
curl $URL //经过5000次循环后，生成一个长的URL地址栏
[root@proxy ~]# ./buffer.sh
.. ..
<center><h1>414 Request-URI Too Large</h1></center> //提示头部信息过大
2) Modify the Nginx configuration file to increase the size of the packet header cache
[root@proxy ~]# vim /usr/local/nginx/conf/nginx.conf
.. ..
http {
client_header_buffer_size 1k; //默认请求包头信息的缓存
large_client_header_buffers 4 4k; //大请求包头部信息的缓存个数与容量
.. ..
}
[root@proxy ~]# /usr/local/nginx/sbin/nginx -s reload
3) After optimization, use the script to test whether the long header request can get a response
[root@proxy ~]# cat buffer.sh
#!/bin/bash
URL=http://192.168.4.5/index.html?
for i in {
1..5000}
do
URL=${URL}v$i=$i
done
curl $URL
[root@proxy ~]# ./buffer.sh
Step 5: The browser caches static data locally
1) Use the Firefox browser to view the cache.
Take Firefox as an example. Entering about:cache in the Firefox address bar will display the cache information of the Firefox browser, as shown in Figure-3. Click List Cache Entries to view the detailed information.
Figure-3
2) Clear firefox local cache data, as shown in Figure-4.
Figure-4
3) Modify the Nginx configuration file to define the cache time for static pages
[root@proxy ~]# vim /usr/local/nginx/conf/nginx.conf
server {
listen 80;
server_name localhost;
location / {
root html;
index index.html index.htm;
}
location ~* \.(jpg|jpeg|gif|png|css|js|ico|xml)$ {
expires 30d; //定义客户端缓存时间为30天
}
}
[root@proxy ~]# cp /usr/share/backgrounds/day.jpg /usr/local/nginx/html
[root@proxy ~]# /usr/local/nginx/sbin/nginx -s reload
#Please make sure that nginx is started, otherwise an error will be reported when you run this command. The error message is as follows:
#[error] open() “/usr/local/nginx/logs/nginx.pid” failed (2: No such file or directory )
4) After optimization, use the Firefox browser to access the picture and check the cache information again
[root@client ~]# firefox http://192.168.4.5/day.jpg
Enter about:cache in the firefox address bar, check the local cache data, check whether there are pictures and whether the expiration time is correct