How can I monitor Nginx logs for DDoS attacks?

Analyze Nginx access and error logs for suspicious patterns, such as a large number of requests from the same IP address, excessive 400 or 500 errors, or unusually high traffic volume. Tools like `fail2ban` can automatically parse logs and take action (e.g., block IPs) based on detected patterns. Log aggregators and SIEM systems can also be used for advanced monitoring.