Logging

This page covers what makes a good log message in Kibana. For how to instantiate and call a logger from your plugin, see the logging service tutorial. For security-sensitive actions that need to be recorded separately, see audit logging.

• Do not log sensitive information (personally identifiable information, passwords, api keys, etc.), regardless of the log level. Err on the side of caution. Personally identifiable information is common in user input; for example, dashboard titles, index names and Elasticsearch _search queries.
• Logs should include just enough information to be actionable.
• Use the right log level. The logging service tutorial shows each level in use; as a rule of thumb: trace/debug for developer diagnostics, info for noteworthy lifecycle events (sparingly — see the HTTP API observability guidance), warn for recoverable anomalies, error/fatal for failures that need attention.
• Use ECS format for any additional LogMeta you add to your logging statements.
• Logs are read by customers, a large number of Elastic employees, and Kibana contributors. As such, log messages should use language that is understandable to a wide audience and should avoid disclosing implementation details (unless they're at the debug/trace level).