Module: SemanticLogger
- Defined in:
- lib/semantic_logger.rb,
lib/semantic_logger/log.rb,
lib/semantic_logger/base.rb,
lib/semantic_logger/logger.rb,
lib/semantic_logger/version.rb,
lib/semantic_logger/loggable.rb,
lib/semantic_logger/appender/base.rb,
lib/semantic_logger/appender/file.rb,
lib/semantic_logger/appender/syslog.rb,
lib/semantic_logger/semantic_logger.rb,
lib/semantic_logger/appender/mongodb.rb,
lib/semantic_logger/appender/wrapper.rb,
lib/semantic_logger/debug_as_trace_logger.rb,
lib/semantic_logger/jruby/garbage_collection_logger.rb
Overview
Wrapper appender
Wraps the Rails log, log4r, or Ruby Logger with the SemanticLogger API's
Defined Under Namespace
Modules: Appender, JRuby, Loggable Classes: Base, DebugAsTraceLogger, Log, Logger
Constant Summary collapse
- VERSION =
'2.18.0'
- LEVELS =
Logging levels in order of most detailed to most severe
[:trace, :debug, :info, :warn, :error, :fatal]
Class Method Summary collapse
-
.[](klass) ⇒ Object
Return a logger for the supplied class or class_name.
-
.add_appender(appender, level = nil, &block) ⇒ Object
Add a new logging appender as a new destination for all log messages emitted from Semantic Logger.
-
.add_signal_handler(log_level_signal = 'USR2', thread_dump_signal = 'TTIN', gc_log_microseconds = 100000) ⇒ Object
Add signal handlers for Semantic Logger.
-
.appenders ⇒ Object
Returns [SemanticLogger::Appender::Base] a copy of the list of active appenders for debugging etc.
-
.backtrace_level ⇒ Object
Returns the current backtrace level.
-
.backtrace_level=(level) ⇒ Object
Sets the level at which backtraces should be captured for every log message.
-
.backtrace_level_index ⇒ Object
Returns the current backtrace level index For internal use only.
-
.default_level ⇒ Object
Returns the global default log level.
-
.default_level=(level) ⇒ Object
Sets the global default log level.
-
.flush ⇒ Object
Wait until all queued log messages have been written and flush all active appenders.
-
.on_metric(&block) ⇒ Object
Supply a block to be called whenever a metric is seen during benchmark logging.
-
.remove_appender(appender) ⇒ Object
Remove an existing appender Currently only supports appender instances.
-
.reopen ⇒ Object
After forking an active process call SemanticLogger.reopen to re-open any open file handles etc to resources.
Class Method Details
.[](klass) ⇒ Object
Return a logger for the supplied class or class_name
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# File 'lib/semantic_logger/semantic_logger.rb', line 7 def self.[](klass) SemanticLogger::Logger.new(klass) end |
.add_appender(appender, level = nil, &block) ⇒ Object
Add a new logging appender as a new destination for all log messages emitted from Semantic Logger
Appenders will be written to in the order that they are added
If a block is supplied then it will be used to customize the format of the messages sent to that appender. See SemanticLogger::Logger.new for more information on custom formatters
Parameters
appender [String|IO|SemanticLogger::Appender::Base|::Logger]
Filename to write log messages to
Or,
STDOUT, STDERR, or any IO stream to write log messages to
Or,
Any SemanticLogger::Appender instance such as
SemanticLogger::Appender::File
SemanticLogger::Appender::Wrapper
SemanticLogger::Appender::Mongodb
Or,
A custom appender derived from SemanticLogger::Appender::Base
Or,
Ruby built-in Logger, or any logger that implements the following methods:
:debug, :info, :warn, :error, :fatal
level [Symbol]
Optional
By setting the level higher than the SemanticLogger::default_level
this appender can exclude lower level log messages
Any one of SemanticLogger::LEVELS. For example: :trace, :debug, :info, :warn, :error, :fatal
Examples:
# Send all logging output to Standard Out (Screen)
SemanticLogger.add_appender(STDOUT)
# Send all logging output to a file
SemanticLogger.add_appender('logfile.log')
# Send all logging output to a file and only :info and above to standard output
SemanticLogger.add_appender('logfile.log')
SemanticLogger.add_appender(STDOUT, :info)
Log to an existing logger:
# Send Semantic logging output to an existing logger
require 'logger'
require 'semantic_logger'
# Built-in Ruby logger
log = Logger.new(STDOUT)
log.level = Logger::DEBUG
SemanticLogger.default_level = :debug
SemanticLogger.add_appender(log)
logger = SemanticLogger['Example']
logger.info "Hello World"
logger.debug("Login time", user: 'Joe', duration: 100, ip_address: '127.0.0.1')
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# File 'lib/semantic_logger/semantic_logger.rb', line 110 def self.add_appender(appender, level=nil, &block) appender_instance = if appender.is_a?(String) || appender.is_a?(IO) # $stderr, STDOUT, other IO, or a filename SemanticLogger::Appender::File.new(appender, level, &block) elsif appender.is_a? Appender::Base # Already an instance of an appender appender.level = level if level appender.formatter = block if block appender else # Check if the custom appender responds to all the log levels. For example Ruby ::Logger if does_not_implement = LEVELS[1..-1].find { |i| !appender.respond_to?(i) } raise "Supplied appender does not implement:#{does_not_implement}. It must implement all of #{LEVELS[1..-1].inspect}" end raise "Change the log level to #{level}, update the log level directly against the supplied appender" if level SemanticLogger::Appender::Wrapper.new(appender, &block) end @@appenders << appender_instance # Start appender thread if it is not already running SemanticLogger::Logger.start_appender_thread appender_instance end |
.add_signal_handler(log_level_signal = 'USR2', thread_dump_signal = 'TTIN', gc_log_microseconds = 100000) ⇒ Object
Add signal handlers for Semantic Logger
Two signal handlers will be registered by default:
-
Changing the log_level:
The log level can be changed without restarting the process by sending the
log_level_signal, which by default is 'USR2'
When the log_level_signal is raised on this process, the global default log level
rotates through the following log levels in the following order, starting
from the current global default level:
:warn, :info, :debug, :trace
If the current level is :trace it wraps around back to :warn
-
Logging a Ruby thread dump
When the signal is raised on this process, Semantic Logger will write the list
of threads to the log file, along with their back-traces when available
For JRuby users this thread dump differs form the standard QUIT triggered
Java thread dump which includes system threads and Java stack traces.
It is recommended to name any threads you create in the application, by
calling the following from within the thread itself:
Thread.current.name = 'My Worker'
Also adds JRuby Garbage collection logging so that any garbage collections that exceed the time threshold will be logged. Default: 100 ms Currently only supported when running JRuby
Note:
To only register one of the signal handlers, set the other to nil
Set gc_log_microseconds to nil to not enable JRuby Garbage collections
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# File 'lib/semantic_logger/semantic_logger.rb', line 216 def self.add_signal_handler(log_level_signal='USR2', thread_dump_signal='TTIN', gc_log_microseconds=100000) Signal.trap(log_level_signal) do index = (default_level == :trace) ? LEVELS.find_index(:error) : LEVELS.find_index(default_level) new_level = LEVELS[index-1] self['SemanticLogger'].warn "Changed global default log level to #{new_level.inspect}" self.default_level = new_level end if log_level_signal Signal.trap(thread_dump_signal) do logger = SemanticLogger['Thread Dump'] Thread.list.each do |thread| next if thread == Thread.current = thread.name if backtrace = thread.backtrace += "\n" << backtrace.join("\n") end = thread[:semantic_logger_tags] = .nil? ? [] : .clone logger.tagged() { logger.warn() } end end if thread_dump_signal if gc_log_microseconds && defined?(JRuby) listener = SemanticLogger::JRuby::GarbageCollectionLogger.new(gc_log_microseconds) Java::JavaLangManagement::ManagementFactory.getGarbageCollectorMXBeans.each do |gcbean| gcbean.add_notification_listener(listener, nil, nil) end end true end |
.appenders ⇒ Object
Returns [SemanticLogger::Appender::Base] a copy of the list of active appenders for debugging etc. Use SemanticLogger.add_appender and SemanticLogger.remove_appender to manipulate the active appenders list
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# File 'lib/semantic_logger/semantic_logger.rb', line 147 def self.appenders @@appenders.clone end |
.backtrace_level ⇒ Object
Returns the current backtrace level
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# File 'lib/semantic_logger/semantic_logger.rb', line 40 def self.backtrace_level @@backtrace_level end |
.backtrace_level=(level) ⇒ Object
Sets the level at which backtraces should be captured for every log message.
By enabling backtrace capture the filename and line number of where message was logged can be written to the log file. Additionally, the backtrace can be forwarded to error management services such as Bugsnag.
Warning:
Capturing backtraces is very expensive and should not be done all
the time. It is recommended to run it at :error level in production.
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# File 'lib/semantic_logger/semantic_logger.rb', line 33 def self.backtrace_level=(level) @@backtrace_level = level # For performance reasons pre-calculate the level index @@backtrace_level_index = level.nil? ? 65535 : level_to_index(level) end |
.backtrace_level_index ⇒ Object
Returns the current backtrace level index For internal use only
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# File 'lib/semantic_logger/semantic_logger.rb', line 46 def self.backtrace_level_index #:nodoc @@backtrace_level_index end |
.default_level ⇒ Object
Returns the global default log level
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# File 'lib/semantic_logger/semantic_logger.rb', line 19 def self.default_level @@default_level end |
.default_level=(level) ⇒ Object
Sets the global default log level
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# File 'lib/semantic_logger/semantic_logger.rb', line 12 def self.default_level=(level) @@default_level = level # For performance reasons pre-calculate the level index @@default_level_index = level_to_index(level) end |
.flush ⇒ Object
Wait until all queued log messages have been written and flush all active appenders
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# File 'lib/semantic_logger/semantic_logger.rb', line 153 def self.flush SemanticLogger::Logger.flush end |
.on_metric(&block) ⇒ Object
Supply a block to be called whenever a metric is seen during benchmark logging
Parameters
block
The block to be called
Example:
SemanticLogger.on_metric do |log_struct|
puts "#{log_struct.metric} was received. Log Struct: #{log_struct.inspect}"
end
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# File 'lib/semantic_logger/semantic_logger.rb', line 177 def self.on_metric(&block) SemanticLogger::Logger.on_metric(&block) end |
.remove_appender(appender) ⇒ Object
Remove an existing appender Currently only supports appender instances
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# File 'lib/semantic_logger/semantic_logger.rb', line 139 def self.remove_appender(appender) @@appenders.delete(appender) end |
.reopen ⇒ Object
After forking an active process call SemanticLogger.reopen to re-open any open file handles etc to resources
Note: Only appenders that implement the reopen method will be called
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# File 'lib/semantic_logger/semantic_logger.rb', line 161 def self.reopen @@appenders.each { |appender| appender.reopen if appender.respond_to?(:reopen) } # After a fork the appender thread is not running, start it if it is not running SemanticLogger::Logger.start_appender_thread end |