serverlogs

Server logs are records produced by computing systems that document events and states related to software, hardware, and networks. They typically capture requests and responses, errors, warnings, and system-level events from servers, services, and devices. Logs originate from web servers, application servers, databases, operating systems, and network devices. Each entry usually includes a timestamp, source, severity, and a message.

Common log types include access logs (which record client requests and responses), error logs (errors and exceptions), application logs (informational messages, debugging), security or audit logs (authentication, authorization events), and system logs (kernel or daemon messages). Formats vary: the Apache/Nginx common log format, JSON-formatted logs, syslog (RFC 5424).

Purposes: troubleshooting, performance monitoring, capacity planning, security incident response, and compliance auditing. Centralized logging collects logs from multiple sources into a central store where they can be searched, correlated, and analyzed. This enables real-time alerting and retrospective investigations.

Data handling: Logs typically contain timestamps, host identifiers, process names, severity levels, and messages; sensitive data should be redacted or masked. Time synchronization (NTP) and consistent time zones improve correlation. Retention policies, rotation, compression, and secure access controls are standard practices to manage volume and protect privacy.

Standards and interoperability: Syslog (RFC 5424), Common Log Format, Combined Log Format; many systems emit JSON for structured logging, which supports schema validation and automated parsing.

Best practices: implement structured logging, use correlation or trace IDs, redact PII, enable log rotation and encryption at rest, enforce access controls, and set up alerts for anomalies. Regular audits and testing help maintain log quality and usefulness.