Function logs

A function writes logs to Yandex Cloud Logging, to the default log group for the folder where the function is located.

There are two types of logs:

• Automatic: Logs of requests to functions.
• Custom: Logs that custom code writes to the standard output (stdout) and standard error output (stderr). The minimum logging level of custom logs is UNSPECIFIED.

Learn more about working with logs in the Yandex Cloud Logging documentation.

Structured logsStructured logs

Apart from text, structured logs in the following JSON format can be written to the stdout and stderr standard output streams:

• message/msg: Entry text.
• level: Logging level. Possible logging levels: TRACE, DEBUG, INFO, WARN, ERROR, and FATAL.
• stream_name: Log stream name. Length: 1 to 63 characters.

All other JSON fields are automatically written to json-payload.

A log must be single-line. Any entry that contains the message/msg field and is up to 64 KB is considered to be a structured log. If the entry size is larger, it is split into multiple records and treated as text.

You can disable structured logs by setting the STRUCTURED_LOGGING = false environment variable. In this case, any JSON log will be considered plain text.

See alsoSee also

• Writing data to the execution log. Function examples.
• Builder. Logging.