How to prevent hotlinking of images or other assets?

TosetupanNginxserverblock,firstunderstanditsstructureusingtheserverdirectivewithsettingslikelisten,server_name,andlocation;next,createadirectorystructureforyoursitesuchas/var/www/example.com/htmlandsetproperpermissions;thenenabletheserverblockbycreat

To block a specific User-Agent, it can be implemented in Nginx, Apache, or code (such as PHP, Python). 1. In Nginx, judge $http_user_agent by if and return 403; 2. In Apache, use SetEnvIfNoCase and Deny to deny access; 3. judge User-Agent in the program and intercept the request. Common UAs that need to be blocked include python-requests, curl, empty UA, etc. Choosing the appropriate method can effectively reduce garbage traffic and security risks.

Key measures to protect the security of Nginx servers include: 1. Configure HTTPS encrypted connections, use Let'sEncrypt free certificates and automatically configure them through Certbot, set up forced jumps and appropriate encryption suites, and enable automatic renewal; 2. Restrict access permissions, protect sensitive paths through IP control and BasicAuth authentication; 3. Turn off information leakage, hide version numbers, prohibit directory browsing, and customize error pages to reduce the attack surface.

To efficiently provide MP4 video files, you need to enable byte range requests, optimize file structure, rational encoding and compression, and adopt strategic caching. First, enable byte range request (Accept-Ranges:bytes) to support video jumps, interrupted broadcasts and adaptive bit rate streams; second, use tools such as qt-faststart to move MOOV atoms to the beginning of the file to achieve bottom-playing; third, use H.264/H.265 encoding, reasonably set the bit rate and enable double-pass encoding to reduce the file size while ensuring quality; finally, by setting long-term Cache-Control headers and using CDN for edge caching, reduce server load and improve response speed.

Nginx failure to start is usually caused by configuration errors, port conflicts, or permission issues. First check the Nginx error log, use the command sudotail-f/var/log/nginx/error.log to view the latest error information in real time; secondly, test the configuration file syntax, run sudonginx-t to ensure there are no syntax errors; then confirm whether other processes occupy port 80 or 443, and use sudonetstat-tulpn|grep':80\|:443' to detect and handle conflicts; finally verify file permissions and ownership to ensure that Nginx has permission to access relevant directories and files.

How to implement HTTP load balancing using Nginx? The answers are as follows: 1. Use the upstream module to define the backend server group and forward the request through proxy_pass in server or location; 2. Support polling, weighted polling, minimum connection and IP hashing policies; 3. You can configure down, backup, fail_timeout and max_fails parameters to enhance stability; 4. After modifying the configuration, execute nginx-t check syntax and use nginx-sreload to take effect. For example, the basic configuration structure includes three backend nodes using polling to distribute traffic by default, while weighted polling allows the allocation of requests by weight, least_conn will send the request

When using server_name in Nginx to match multiple domains or subdomains, it can be achieved through wildcards and regular expressions. 1. When using wildcards, the asterisk can only be used for the beginning or ending, and must be a complete label boundary. For example, .example.com can match first-level subdomains but does not include root domains or multi-level subdomains. If you need to match both root domains and first-level subdomains, it should be written as example.com*.example.com; 2. When using regular expressions, you must start with ~, such as ~^\w .(dev|test)$ can match domain names ending with .dev or .test, and support capture group calls; 3. The matching priority is the exact name>Longest wildcard prefix>Longest wildcard suffix&

Set worker_processes to auto (i.e., the number of CPU cores) to make full use of multi-core performance; 2. Set worker_connections (such as 1024 or higher) according to the system file descriptor limitation and expected traffic to ensure that ulimit-n is large enough; 3. The maximum number of concurrent connections = worker_processes × worker_connections, reasonable configuration can support thousands to tens of thousands of connections, avoid bottlenecks, and improve the performance of Nginx production environment.