nginx load balancing upstream and proxy_pass - (linux operation and maintenance 23)

1. Cluster preparation

Cluster: a group of servers doing the same work

1.1 cluster construction of virtual environment

The web01 virtual machine will be shut down first for cloning. Boot configuration ip hostname
The configuration of the web cluster is as follows:

Host nameip
web01192.168.246.7
web02192.168.246.8
web03192.168.246.9
Modify host name
hostnamectl set-hostname web02
 modify ip
sed -i 's#\.8#.9#g' /etc/sysconfig/network-scripts/ifcfg-eth[01]
sed -i '/UUID/d' /etc/sysconfig/network-scripts/ifcfg-eth[01]
Restart the network
systemctl restart network

Just reconnect

1.2 deployment of Enterprise Clusters

1. First deploy an lnmp server and upload code information
2. Conduct access test
3. Batch deploy multiple web servers (ansible)
4,. Distribute nginx configuration files
5. Distribute the site directory to all hosts

2. Configuration of load balancing server

2.1 clone a new machine with template machine

Modify ip and host name. The method is the same as above

hostnameip
lb01192.168.246.5

2.2 installation nginx

Configure yum source: https://nginx.org/en/linux_packages.html

vim //etc/yum.repos.d/nginx.repo

[nginx-stable]
name=nginx stable repo
baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true

Installing nginx:

yum -y install nginx

Start:

systemctl start nginx
systemctl enable nginx

2.3 write the configuration file of nginx for load balancing

Two modules
1. Load balancing
ngx_http_upstream_module --upstream
2. Reverse proxy (e.g. intranet – intranet – extranet (from inside to outside))
ngx_http_proxy_module --proxy_pass

2.4 simple load balancing profile

vim /etc/nginx/conf.d/lb.conf

upstream yq{
       server 192.168.246.7:80;
       server 192.168.246.8:80;
       server 192.168.246.8:80;
    }
    server {
        listen       80;
        server_name  www.yq.com;
        location / {
           proxy_pass http://yq;
        }
    }

systemctl restart nginx

There is no problem with such a simple configuration when one website is running, but multiple websites will appear:
1. The website page is disordered
2. If the server has a problem, it also displays an error
3. Unable to collect the customer's ip address for statistical analysis

2.5 special attention: upstream yq and proxy_ pass http://yq The back YQ of the must be the same

2.6 realize load balancing function

Three web Operations (all operations):

mkdir /html/{bbs,www} -p

web01
for name in www bbs ;do echo "$name 192.168.246.7">/html/$name/idenx.html;done

web02
for name in www bbs ;do echo "$name 192.168.246.8">/html/$name/idenx.html;done

web03
for name in www bbs ;do echo "$name 192.168.246.9">/html/$name/idenx.html;done

chown -R www.www /html

nginx profile:
/Create www.conf bbs.conf under / etc/nginx/conf.d /
www.conf:

server{
  listen 80;
  server_name www.yq.com;
  access_log /var/log/nginx/www_log.log main;
  error_log /var/log/nginx/www_log.log warn;
  location /{
       root /html/www;
       index index.html;  
   }
}

bbs.conf:

server{
  listen 80;
  server_name bbs.yq.com;
  access_log /var/log/nginx/www_log.log main;
  error_log /var/log/nginx/www_log.log warn;
  location /{
       root /html/bbs;
       index index.html;
   }
}

systemctl reload nginx

Configure windows hosts file

192.168.246.5 blog.yq.com www.yq.com

Browser access:

www.yq.com
bbs.yq.com

Load balancing server lb01:

vim /etc/hosts
172.16.1.5 www.yq.com bbs.yq.com

curl www.yq.com
curl bbs.yq.com

3. ngx_http_upstream_module details

3.1 different scheduling functions

1. The default is average allocation
2. Self distribution (more capable)
To modify a profile:

upstream yq{
       server 192.168.246.7:80 weight=3;
       server 192.168.246.8:80 weight=2;
       server 192.168.246.8:80 weight=1;
    }

Six such visits,
3 times on web01(192.168.246.7)
Twice web02(192.168.246.8)
1 web01(192.168.246.9)

3.2 backup function

configuration file

upstream yq{
       server 192.168.246.7:80;
       server 192.168.246.8:80;
       server 192.168.246.8:80 backup;
    }

If the first two servers don't work, the third one will be used

3.3 maximum number of failures. Resend the request after failure (max_failures = 5 fail timeout = 10s)

configuration file

upstream yq{
       server 192.168.246.7:80 max_fails=5 fail_time=10s;
       server 192.168.246.8:80;
       server 192.168.246.8:80;
    }

After the web01 connection fails five times, the connection will be sent again in 10s

3.4 different scheduling algorithms

1.rr rotation training scheduling algorithm
2.wrr weight scheduling algorithm
3.ip_ Hash (when repeated login occurs)

When we log in to the website, the card will appear in the login interface. At this time, the request is a different web server every time

Solution: ip_hash

configuration file

upstream yq{
       ip_hash;
       server 192.168.246.7:80;
       server 192.168.246.8:80;
       server 192.168.246.8:80 backup;
    }

In this way, when there is little access, it is based on his MD5 that the server is accessed all the time, and the load balance is uneven

3.2 the cache server can also solve this problem (later)

4.lest_ Conn (allocate resources according to the number of connections to the server)

4. ngx_http_proxy_module module

Problems that can be solved:

4.1 when visiting different websites, problems of different websites cannot be displayed

Edit profile:

upstream yq  {
       server 192.168.246.7:80;
       server 192.168.246.8:80;
       server 192.168.246.9:80;
    }
server {
         
        listen       80;
        server_name  www.yq.com;
        location / {
           proxy_pass http://yq;
           #Different URLs display different interfaces
           proxy_set_header Host $host;
        }
    }

4.2 the address information of access users cannot be counted

proxy_set_header X-Forwarded-For $remote_addr;

upstream yq  {
       server 192.168.246.7:80;
       server 192.168.246.8:80;
       server 192.168.246.9:80;
    }
server {
         
        listen       80;
        server_name  www.yq.com;
        location / {
           proxy_pass http://yq;
           #Different URLs display different interfaces
           proxy_set_header Host $host;
           # The address information of users accessing the website cannot be analyzed and counted
	   proxy_set_header X-Forwarded-For $remote_addr;
        }
    }

Format of log file

cat /etc/nginx/nginx.conf

log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';
    access_log  /var/log/nginx/access.log  main;
    
    $remote_addr   			Show user access sources IP Address information
    $remote_user            Displays user name information for authentication
	[$time_local]           Displays the time when the site was visited
	"$request"              Request line information of request message
    $status                 User access site status code information
	$body_bytes_sent        Displays data size information for the response
	$http_referer           Record the connection address information of calling website resources(Prevent users from stealing chains)                             
	$http_user_agent        Record what client software the user uses to access the page  (Google Firefox IE Android iphone)
	$http_x_forwarded_for   load balancing  ip

$http_x_forwarded_for is the ip address accessed
Visit the website to view the log file:
On web01

cat /var/log/nginx/access_www.log

192.168.246.5 - - [20/Sep/2021:10:52:31 +0800] "GET /wenwen.html HTTP/1.0" 200 6 "-" 
"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) 
Chrome/92.0.4515.131 Safari/537.36" "192.168.246.1"

192.168.246.5 is the address of the load balancing proxy server, and 192.168.246.1 is the ip address accessed

4.3 the error page will show the problem

upstream yq  {
       server 192.168.246.7:80;
       server 192.168.246.8:80;
       server 192.168.246.9:80;
    }
server {
         
        listen       80;
        server_name  www.yq.com;
        location / {
           proxy_pass http://yq;
           #Different URLs display different interfaces
           proxy_set_header Host $host;
           #The error page is not displayed to the user
           proxy_next_upstream error timeout http_404 http_502 http_403;
           # The address information of users accessing the website cannot be analyzed and counted
	   proxy_set_header X-Forwarded-For $remote_addr;
        }
    }

systemctl reload nginx

4.4 complete configuration file

upstream yq  {
       server 192.168.246.7:80;
       server 192.168.246.8:80;
       server 192.168.246.9:80;
    }
server {
         
        listen       80;
        server_name  www.yq.com;
        location / {
           proxy_pass http://yq;
           #Different URLs display different interfaces
           proxy_set_header Host $host;
           #The error page is not displayed to the user
           proxy_next_upstream error timeout http_404 http_502 http_403;
           # The address information of users accessing the website cannot be analyzed and counted
	   proxy_set_header X-Forwarded-For $remote_addr;
        }
    }
server {

        listen       80;
        server_name  bbs.yq.com;
        location / {
           proxy_pass http://yq;
           proxy_set_header Host $host;
           proxy_next_upstream error timeout http_404 http_502 http_403;
        }
    }


systemctl reload nginx

This is the configuration file of the blog website; You can add it or not

server {
        listen       80;
        server_name  blog.yq.com;
        location / {
           proxy_pass http://yq;
           proxy_set_header Host $host;
           proxy_next_upstream error timeout http_404 http_502 http_403;
        }
    }

Keywords: Linux Operation & Maintenance Nginx

Added by sasi on Mon, 20 Sep 2021 17:01:00 +0300

Popular Keywords

©2024 Programming VIP