Fluent logger
A structured event logger
Examples
Simple
require 'fluent-logger'
log = Fluent::Logger::FluentLogger.new(nil, :host => 'localhost', :port => 24224)
unless log.post("myapp.access", {"agent" => "foo"})
p log.last_error # You can get last error object via last_error method
end
# output: myapp.access {"agent":"foo"}
UNIX socket
require 'fluent-logger'
log = Fluent::Logger::FluentLogger.new(nil, :socket_path => "/tmp/fluent.sock")
unless log.post("myapp.access", {"agent" => "foo"})
p log.last_error # You can get last error object via last_error method
end
# output: myapp.access {"agent":"foo"}
Singleton
require 'fluent-logger'
Fluent::Logger::FluentLogger.open(nil, :host => 'localhost', :port => 24224)
Fluent::Logger.post("myapp.access", {"agent" => "foo"})
# output: myapp.access {"agent":"foo"}
Tag prefix
require 'fluent-logger'
log = Fluent::Logger::FluentLogger.new('myapp', :host => 'localhost', :port => 24224)
log.post("access", {"agent" => "foo"})
# output: myapp.access {"agent":"foo"}
Standard ::Logger compatible interface
Example1
require 'fluent-logger'
f = Fluent::Logger::LevelFluentLogger.new('fluent')
f.info("some application running.")
# output: fluent.info: {"level":"INFO","message":"some application running."}
f.warn("some application running.")
# output: fluent.warn: {"level":"WARN","message":"some application running."}
Example2(add progname)
require 'fluent-logger'
f = Fluent::Logger::LevelFluentLogger.new('fluent')
f.info("some_application") {"some application running."}
# output: fluent.info: {"level":"INFO","message":"some application running.","progname":"some_application"}
Example3(set log level)
require 'fluent-logger'
f = Fluent::Logger::LevelFluentLogger.new('fluent')
f.level = Logger::WARN
f.info("some_application") {"some application running."}
Log level is ERROR so no output.
default log level is debug.
Example4(customize format for Rails)
require 'fluent-logger'
f = Fluent::Logger::LevelFluentLogger.new('fluent')
f.formatter = proc do |severity, datetime, progname, |
map = { level: severity }
map[:message] = if
map[:progname] = progname if progname
map[:stage] = ENV['RAILS_ENV']
map[:service_name] = "SomeApp"
map
end
f.info("some_application"){"some application running."}
# output: fluent.info: {"level":"INFO","message":"some application running.","progname":"some_application","stage":"production","service_name":"SomeApp"}
Loggers
Fluent
Fluent::Logger::FluentLogger.open('tag_prefix', :host => 'localhost', :port => 24224)
Console
Fluent::Logger::ConsoleLogger.open(io)
Null
Fluent::Logger::NullLogger.open
Tips
Use nanosecond-precision time
To send events with nanosecond-precision time (Fluent 0.14 and up), specify nanosecond_precision
to FluentLogger
constructor.
log = Fluent::Logger::FluentLogger.new(nil, :host => 'localhost', :port => 24224, :nanosecond_precision => true)
# Use nanosecond time instead
log.post("myapp.access", {"agent" => "foo"})
log.post_with_time("myapp.access", {"agent" => "foo"}, Time.now) # Need Time object for post_with_time
Buffer overflow
You can inject your own custom proc to handle buffer overflow in the event of connection failure. This will mitigate the loss of data instead of simply throwing data away.
Your proc must accept a single argument, which will be the internal buffer of messages from the logger. A typical use-case for this would be writing to disk or possibly writing to Redis.
Example
class BufferOverflowHandler
attr_accessor :buffer
def flush()
@buffer ||= []
MessagePack::Unpacker.new.feed_each() do |msg|
@buffer << msg
end
end
end
handler = Proc.new { || BufferOverflowHandler.new.flush() }
Fluent::Logger::FluentLogger.new(nil,
:host => 'localhost', :port => 24224,
:buffer_overflow_handler => handler)
Information
name | description |
---|---|
Web site | http://fluentd.org/ |
Documents | http://docs.fluentd.org/ |
Source repository | https://github.com/fluent/fluent-logger-ruby |
Author | Sadayuki Furuhashi |
Copyright | (c) 2011 FURUHASHI Sadayuki |
License | Apache License, Version 2.0 |