nginx load balancing and detailed configuration methods

upstream backend {
    server  fail_timeout=60s max_fails=2;
    server  fail_timeout=60s max_fails=2;
}
max_fails=2; Indicates if fail_timeout During the time period，Nginx The number of failed requests to a certain upstream server has been reached 2 Second-rate，The server is considered unavailable。
fail_timeout=60s; It has two functions：first，It defines the above max_fails The length of time window mentioned in，In this example 60 Second；其Second-rate，Once an upstream server is deemed unavailable，Nginx Will be in the next 60 Second内不再向这台服务器转发任何请求。
This configuration helps improve service reliability，By automatically disabling servers that appear to have failed，And try to connect them again after a while，This avoids sending client requests to unhealthy servers。
In this configuration，if  exist 60 Second内连续失败 2 Second-rate请求，Nginx It will temporarily stop forwarding requests to it 60 Second，and forward the request only to 。Similarly，for  The same rules will be applied。This setup ensures that even if there is a problem with one server，The user can still be directed to another available server。

upstream backend {
    server 192.168.1.1:80 weight=10;  # High-performance server, handle more requests    server 192.168.1.2:80 weight=5;   # Low performance server, handles fewer requests}

upstream backend { 
ip_hash; # Enable IP hashing policyserver 192.168.1.1:80; 
server 192.168.1.2:80; 
}
------------------------------------------------------
upstream fileserver {
		ip_hash;
        server 192.19.31.91:32100 fail_timeout=60s max_fails=2;
        server 192.19.31.92:32100 fail_timeout=60s max_fails=2;
		keepalive 100;
    }

upstream backend {
    least_conn;  # Enable the minimum connection policy    server 192.168.1.1:80;
    server 192.168.1.2:80;
}

upstream backend {
    least_conn;
    server 192.168.1.1:80 weight=10;  # High-end server, higher weight, allowing processing more connections    server 192.168.1.2:80 weight=5;   # Low-weighting server, low weight, protect its load}

upstream backend {
    hash $request_uri consistent;  # Enable consistent hashing for URL hashing, `consistent` (reduces hashing redistribution when server changes)    server 192.168.1.1:80;
    server 192.168.1.2:80;
}

nginx -t             Check if there are syntax errors in the configuration file
nginx -s reload       Hot loading，Reload the configuration file
nginx -s stop         Quickly close
nginx -s quit         Wait for the worker process to close after completing

[Unit]
Description=Nginx Web Server
After=
[Service]
Type=forking
ExecStart=/usr/local/nginx/sbin/nginx  -c /usr/local/nginx/conf/    #Modify nginx directoryExecReload=/usr/local/nginx/sbin/nginx -s reload
ExecStop=/usr/local/nginx/sbin/nginx -s stop
KillMode=process
Restart=always
RestartSec=5s
StartLimitInterval=0
[Install]
WantedBy=

Start the installation（Start up automatically）nginx
sudo systemctl daemon-reload   //Reload the systemd servicesudo systemctl enable 
sudo systemctl start 
systemctl status 
systemctl restart 

user nginx;   # Nginx worker process running user (default: nginx, can be changed to other users)worker_processes auto;   # Number of worker processes, usually set to the number of CPU cores (default: 1, recommended to set to auto or actual cores)error_log /var/log/nginx/;    #Error Logpid /run/;
# Load dynamic modules. See /usr/share/doc/nginx/.
include /usr/share/nginx/modules/*.conf;
events {
    worker_connections 1024;    # Define the maximum number of connections per worker process.  Set to 1024 here, which means that each process can process up to 1024 concurrent connections}
http {
    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';
#Define log format main, used to record access logs#$remote_addr: Client IP address# $time_local: Request time.#$request`: The original line requested by the client (such as `GET/HTTP/1.1)#$status: Response status code (such as 200, 404)#$body_bytes_sent: The number of bytes sent to the client (excluding response headers)#$http_referer: Request source page#$http_user_agent: Client browser identity#$http_x_forwarded_for: Client IP in the proxy chain (for reverse proxy scenarios)    access_log  /var/log/nginx/  main;
    sendfile            on;    #Enable efficient file transfer mode (send files directly from disk to the network)    tcp_nopush          on;    #Optimize TCP data transfer (use combined to reduce latency)    tcp_nodelay         on;    #Optimize TCP data transfer (use combined to reduce latency)    keepalive_timeout   65;    #Set client connection holding time (unit: seconds) to reduce TCP handshake overhead    types_hash_max_size 2048;  #Define the size of the MIME type hash table to avoid hash conflicts    include             /etc/nginx/;
    default_type        application/octet-stream;
    # Load modular configuration files from the /etc/nginx/ directory.
    # See /en/docs/ngx_core_module.html#include
    # for more information.
    include /etc/nginx//*.conf;   #Load all .conf files in the /etc/nginx// directory.  Typically used to organize multiple virtual hosts or modular configurations#Function: Define an HTTP server that listens to port 80    server {
        listen       80 default_server;   # Listen to IPv4's port 80 and serve as the default server (used when other `server_name` is not matched)        listen       [::]:80 default_server;  # Listen to IPv4's port 80 and serve as the default server (used when other `server_name` is not matched)        server_name  _;   # _ means wildcard, matching all unspecified domain names        root         /usr/share/nginx/html;   #Set the website root directory, static files (such as ``) need to be placed in this directory        # Load configuration files for the default server block.
        include /etc/nginx//*.conf;   # Load the additional configuration file for the default server (usually used to override or extend the default configuration)#Function: Define the processing rules for the root path `/`.  Currently empty, indicating the default behavior is used (returning files under the `root` directory).#Extension suggestions: You can add proxy, redirect or static file processing logic here        location / {
        }
# Define 404 The error page is `/`.  `location = /` means exact match `/` path (must ensure that the file exists)        error_page 404 /;
            location = / {
        }
# Define the 5xx error page as `/` (such as server internal errors, gateway errors, etc.).        error_page 500 502 503 504 /;
            location = / {
        }
    }
# Enable HTTPS service (the commented out needs to be uncommented and configured)#Key Configuration#listen 443 ssl http2; Listen to port 443 and enable SSL/TLS and HTTP/2.#ssl_certificate and ssl_certificate_key specify the SSL certificate and private key paths.#ssl_ciphers: Defines the encryption suite (PROFILE=SYSTEM means using the system default configuration).#ssl_prefer_server_ciphers on; Priority to using server-side encryption suite#LS Server Configuration (Comment Section)# Settings for a TLS enabled server.
#
#    server {
#        listen       443 ssl http2 default_server;
#        listen       [::]:443 ssl http2 default_server;
#        server_name  _;
#        root         /usr/share/nginx/html;
#
#        ssl_certificate "/etc/pki/nginx/";
#        ssl_certificate_key "/etc/pki/nginx/private/";
#        ssl_session_cache shared:SSL:1m;
#        ssl_session_timeout  10m;
#        ssl_ciphers PROFILE=SYSTEM;
#        ssl_prefer_server_ciphers on;
#
#        # Load configuration files for the default server block.
#        include /etc/nginx//*.conf;
#
#        location / {
#        }
#
#        error_page 404 /;
#            location = / {
#        }
#
#        error_page 500 502 503 504 /;
#            location = / {
#        }
#    }
}

#Safety related    add_header X-Frame-Options SAMEORIGIN; # Only allow this site to use frames to nest    add_header X-Content-Type-Options nosniff; # Sniffing file types is prohibited    add_header X-XSS-Protection "1; mode=block"; # # XSS Protection    add_header Content-Security-Policy "script-src * 'unsafe-inline' 'unsafe-eval'";
    add_header Referrer-Policy 'origin';
    add_header Strict-Transport-Security "max-age=63072000; includeSubdomains; preload";
	add_header X-Download-Options noopen;
	add_header X-Permitted-Cross-Domain-Policies none;
    server_tokens off;
    access_log off;
    proxy_http_version 1.1;
    proxy_set_header Connection "";
    proxy_connect_timeout 6000;                     #nginx and backend server connection timeout timeout (proxy connection timeout)    proxy_send_timeout 6000;                     # Backend server data return time (Proxy send timeout)    proxy_read_timeout 6000;                     #After the connection is successful, the backend server response time (proxy reception timeout)    proxy_buffer_size 1024k;                      #Set the buffer size of the proxy server (nginx) to save user header information    proxy_buffers 16 1024k;                       #proxy_buffers buffer, if the web page is below 32k on average, set this way    proxy_busy_buffers_size 2048k;                   #Buffer size under high load (proxy_buffers*2)    proxy_temp_file_write_size 2048k;             #Set the cache folder size, which is greater than this value, and will be passed from the upstream server    client_max_body_size 2048m; #The maximum number of single file bytes allowed by the client to request    client_body_buffer_size 128k; #The maximum number of bytes requested by the buffer proxy buffers the user side    server_names_hash_bucket_size 128; #The hash table size of the server name    proxy_intercept_errors on;
    client_header_buffer_size 512k; #Solve the request header size get request too long    large_client_header_buffers 4 512k; #Solve the request header size get request too long    gzip on; #Enable gzip compression output    gzip_min_length 1k; #No compression threshold, only those greater than 1K are compressed, and generally no need to change it    gzip_buffers 4 16k; #It means to apply 4 memory units of 16k as the compressed result stream cache. The default value is to apply for the same memory space as the original data size to store gzip compressed results.    gzip_http_version 1.0; #Compressed version (default 1.1, if the front end is squid2.5, please use 1.0)    gzip_comp_level 2; #Compression Level    gzip_types text/plain application/javascript application/x-javascript text/css application/xml text/javascript application/x-httpd-php image/jpeg image/gif image/png application/json;
    gzip_disable "MSIE [1-6]\."; 
# Set expiration time according to file type    location ~.*\.css$ {
    expires 1d;
    break;
}
location ~.*\.js$ {
    expires 1d;
    break;
}
location ~ .*\.(gif|jpg|jpeg|png|bmp|swf)$ {
    access_log off;
    expires 15d;    #Save for 15 days    break;
}
# curl -x127.0.0.1:80 /static/image/common/ -I # test the max-age of the image# Prohibit file caching#The development environment often changes code, because the browser cache needs to be forced to refresh to see the effect.  This is what we can prohibit browser cache to improve efficiencylocation ~* \.(js|css|png|jpg|gif)$ {
    add_header Cache-Control no-store;
}