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Next generation logging system for Ruby to support highly concurrent, high throughput, low latency systems
Latest commit 62d042 @reidmorrison Merge pull request #17 from constXife/master
AwesomePrint payload when using colorized formatter

semantic_logger Build Status

Low latency, high throughput, enterprise-scale logging system for Ruby


Semantic Logger Guide

Reference Documentation


Logging to the following destinations are all supported "out-of-the-box":

  • File
  • Screen
  • MongoDB
  • BugSnag
  • NewRelic
  • Splunk
  • Syslog
  • Roll-your-own

Semantic Logger is capable of logging thousands of lines per second without slowing down the application. Traditional logging systems make the application wait while the log information is being saved. Semantic Logger avoids this slowdown by pushing log events to an in-memory queue that is serviced by a separate thread that only handles saving log information to multiple destinations at the same time.


Semantic Logger is tested and supported on the following Ruby platforms:

  • Ruby 2.0 and above
  • JRuby 1.7 and above
  • JRuby and above
  • Rubinius 2.5 and above

The following gems are only required when their corresponding appenders are being used, and are therefore not automatically included by this gem:

  • Bugsnag Appender: gem 'bugsnag'
  • MongoDB Appender: gem 'mongo' 1.9.2 or above
  • NewRelic Appender: gem 'newrelic_rpm'
  • Syslog Appender: gem 'syslog_protocol' 0.9.2 or above
  • Syslog Appender to a remote syslogng server over TCP or UDP: gem 'net_tcp_client'
  • Splunk Appender: gem 'splunk-sdk-ruby'


gem install semantic_logger

Upgrade Notes:


Ruby 1.8 is no longer supported, see Ruby 1.8.7 EOL


Rails logging is no longer automatically replaced when including SemanticLogger. Include the rails_semantic_logger gem to replace the Rails default logger with SemanticLogger


This project uses Semantic Versioning.


Reid Morrison :: @reidmorrison



Copyright 2012, 2013, 2014, 2015 Reid Morrison

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

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