log
What is a .log file?
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LOG files are plain-text records of events emitted by software, typically one entry per line with a timestamp, severity, and message. There is no single standard, so formats range from unstructured text to structured JSON lines. They are central to debugging, monitoring, and auditing.
How to use a .log file
Use an example LOG file to test log parsers, timestamp and severity extraction, line-oriented streaming, and ingestion into monitoring or analysis pipelines.
Download example .log files
- Nginx Access LogAn nginx combined-format access log with several requests, including a 403 and a 404 — for testing log parsers.
- Apache Access Log — Common Format (log)An Apache access log in the Common Log Format (CLF) — client, timestamp, request line, status, and byte count. Deterministic, with reserved documentation IPs. Paired with a Combined-format twin for testing log parsers.
- Apache Access Log — Combined Format (log)An Apache access log in the Combined Log Format — the Common fields plus referer and user-agent. A realistic web-server log for testing access-log parsers, analytics, and grok patterns.
- Syslog Messages — RFC 3164 (log)A BSD-style syslog (RFC 3164) sample — timestamp, host, process and PID, then the message, across sshd, cron, kernel, nginx, and application entries. A fixture for testing syslog parsers and forwarders.
- Docker Container Log — json-file driver (log)A Docker json-file container log — one JSON object per line with the log text, stream (stdout/stderr), and an RFC 3339 timestamp, exactly as Docker's default logging driver writes it. A fixture for container-log shippers and parsers.
- Kubernetes Component Log — klog (log)A Kubernetes-component log in the klog/glog format — a severity letter, timestamp, thread id, and source location prefix followed by the message. A fixture for testing klog parsers and severity extraction.
- Structured Log — logfmt (log)A structured application log in logfmt — space-separated key=value pairs (ts, level, msg, method, path, status, duration, request_id) as used by many Go and Heroku-style services. A fixture for testing logfmt parsers.
- Java Stack Trace (log)A realistic Java stack trace — a Spring-style NullPointerException with a nested 'Caused by' chain and '... N more' elision. A fixture for testing stack-trace parsers, error groupers, and log viewers.
and 28 more in the library.