The Nginx Error Log Classifier skill processes Nginx error logs to identify, classify, and prioritize issues affecting web application delivery. It parses error.log entries using regex patterns matched against a curated database of known Nginx error signatures, categorizing them into upstream failures, SSL/TLS errors, configuration issues, and resource exhaustion events.

The skill integrates with GoAccess for real-time log analysis and can process access.log entries to correlate error spikes with traffic patterns. It maps upstream timeout and connection refused patterns to specific backend services by cross-referencing Nginx upstream block configurations, helping identify which microservice is degraded.

Advanced capabilities include SSL handshake failure diagnosis by inspecting certificate chains via OpenSSL s_client, worker process crash analysis through core dump inspection, and rate limiting effectiveness evaluation by analyzing limit_req and limit_conn zone statistics. The skill generates actionable Nginx configuration snippets for resolving detected issues, including buffer size adjustments, keepalive tuning, and proxy timeout optimization.