User Guide

Activate Debug Logging for Tornado

The tornado_common_logger crate contains the logger configuration for the Tornado components.

The configuration is based on three entries:

  • level: A list of comma separated logger verbosity levels. Valid values for a level are: trace, debug, info, warn, and error. If only one level is provided, this is used as global logger level. Otherwise, a list of per package levels can be used. E.g.:

    • level=info: the global logger level is set to info

    • level=warn,tornado=debug: the global logger level is set to warn, the tornado package logger level is set to debug

  • stdout-output: A boolean value that determines whether the Logger should print to standard output. Valid values are true and false.

  • file-output-path: An optional string that defines a file path in the file system. If provided, the Logger will append any output to that file.

The configuration subsection logger.tracing_elastic_apm allows to configure the connection to Elastic APM for the tracing functionality. The following entries can be configured:

  • apm_output: Whether the Logger data should be sent to the Elastic APM Server. Valid values are true and false.

  • apm_server_url: The URL of the Elastic APM Server.

  • apm_server_api_credentials.id: (Optional) the ID of the API Key for authenticating to the Elastic APM server.

  • apm_server_api_credentials.key: (Optional) the key of the API Key for authenticating to the Elastic APM server. If apm_server_api_credentials.id and apm_server_api_credentials.key are not provided, they will be read from the file <config_dir>/apm_server_api_credentials.json

  • exporter.max_queue_size: (Optional) The maximum queue size of the tracing batch exporter to buffer spans for delayed processing. Defaults to 65536.

  • exporter.scheduled_delay_ms: The delay interval in milliseconds between two consecutive exports of batches. Defaults to 5000 (5 seconds).

  • exporter.max_export_batch_size: The maximum number of spans to export in a single batch. Defaults to 512.

  • exporter.max_export_timeout_ms: The time (in milliseconds) for which the export can run before it is cancelled. Defaults to 30000 (30 seconds).

In Tornado executables, the Logger configuration is usually defined with command line parameters managed by structopt. In that case, the default level is set to warn, stdout-output is disabled and the file-output-path is empty.

For example:

./tornado --level=info --stdout-output --file-output-path=/tornado/log