components::Logging Class Reference

Table of Contents

• Detailed Description
• Static options:
• Logs output
• testsuite-capture options:
• Static configuration example:
• Public Member Functions
• Static Public Member Functions
• Static Public Attributes
• Member Function Documentation
• GetLogger()
• GetLoggerOptional()

#include <userver/logging/component.hpp>

Detailed Description

Logging component

Allows to configure the default logger and/or additional loggers for your needs.

Static options:

Name	Description	Default value
file_path	path to the log file	-
level	log verbosity	info
format	log output format, either tskv or ltsv	tskv
flush_level	messages of this and higher levels get flushed to the file immediately	warning
message_queue_size	the size of internal message queue, must be a power of 2	65536
overflow_behavior	message handling policy while the queue is full: discard drops messages, block waits until message gets into the queue	discard
testsuite-capture	if exists, setups additional TCP log sink for testing purposes	{}
fs-task-processor	task processor for disk I/O operations for this logger	fs-task-processor of the loggers component

Logs output

You can specify logger output, in file_path option:

• Use @stdout to write your logs to standard output stream;
• Use @stderr to write your logs to standard error stream;
• Use @null to suppress sending of logs;
• Use file_name% to write your logs in file. Use USR1 signal or OnLogRotate handler to reopen files after log rotation;
• Use unix:socket_name% to write your logs to unix socket. Socket must be created before the service starts and closed by listener afert service is shuted down.

testsuite-capture options:

Name	Description	Default value
host	testsuite hostname, e.g. localhost	-
port	testsuite port	-

Static configuration example:

    logging:
      fs-task-processor: fs-task-processor
      loggers:
        access:
          file_path: $access_log_path
          overflow_behavior: discard
          format: raw
        access-tskv:
          file_path: $access_tskv_log_path
          overflow_behavior: discard
          format: raw
        default:
          file_path: $default_log_path
          level: $log_level
          level#fallback: debug
          overflow_behavior: discard
        tracer:
          file_path: '@stdout'
          overflow_behavior: discard

default section configures the default logger for LOG_*.

Definition at line 79 of file component.hpp.

Inheritance diagram for components::Logging:

Collaboration diagram for components::Logging:

Public Member Functions
	Logging (const ComponentConfig &, const ComponentContext &)
	The component constructor.
logging::LoggerPtr	GetLogger (const std::string &name)
	Returns a logger by its name.
logging::LoggerPtr	GetLoggerOptional (const std::string &name)
	Returns a logger by its name.
void	StartSocketLoggingDebug (const std::optional< logging::Level > &log_level)
void	StopSocketLoggingDebug (const std::optional< logging::Level > &log_level)
void	OnLogRotate ()
	Reopens log files after rotation.
void	TryReopenFiles ()
void	WriteStatistics (utils::statistics::Writer &writer) const

Static Public Member Functions
static yaml_config::Schema	GetStaticConfigSchema ()

Static Public Attributes
static constexpr std::string_view	kName = "logging"
	The default name of components::Logging component.

Member Function Documentation

GetLogger()

logging::LoggerPtr components::Logging::GetLogger

(

const std::string &

name

)

Returns a logger by its name.

Parameters

name	Name of the logger

Returns

Pointer to the Logger instance

Exceptions

std::runtime_error

if logger with this name is not registered

GetLoggerOptional()

logging::LoggerPtr components::Logging::GetLoggerOptional

(

const std::string &

name

)

Returns a logger by its name.

Parameters

name	Name of the logger

Returns

Pointer to the Logger instance, or nullptr if not registered

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The documentation for this class was generated from the following file:

• userver/logging/component.hpp