SmarterLogging

SmarterLogging helps you standardize the log format for your mission critical data in a single-line format, using either key=value format or JSON format, so it can be easily ingested for data analytics. The format lends itself to being easily importable by SumoLogic and Splunk.

Ingesting the Rails logger format in Splunk or Sumologic can be painful, because it is a multi-line format, and what you log from Rails is typically not standardized.

This gem is opinionated and adds standard fields, such at the UTC timestamp, durations, and a request ID, and helps separate "anomalies" from "activities". The main idea is to have dedicated log files for activities which happen during normal operations, as well as anomalies which happen when something unexpected happens.

When using the key=value format, each log line starts with a UTC timestamp in ISO8601 format, and contains space-separated key=value pairs. If a value contains spaces, it is quoted: key="value". The advantage of ISO6801 timestamps is that they are both standardized / easy to parse, as well as human readable.

  time=2017-01-30T21:21:04.013Z activity=some_unique_name key1=value1 key2="value 2"

The only place where this gem is very opinionated is that UTC time is used for logging.

Tip: If you are currently not using UTC time in your application, you should seriously consider doing that - it makes it much easier analyzing logs and errors when dealing with clients and servers which can be anywhere in the world.

Key goals:

• get average call durations
• get activity and anomaly logs
• help forensics on any calls / trace incidents
• quickly identify top anomalies
• get timings for blocks of code

Add this line to your application's Gemfile:

gem 'smarter_logging'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install smarter_logging

When included in a Rails project, two default loggers are defined:

SmarterLogging.anomaly_logger
SmarterLogging.activity_logger

Each of them provides a log() method.

As a shortcut, you can include SmarterLogging and do this:

SmarterLogging.log_anomaly(unique_key, params)
SmarterLogging.log_activity(unique_key, params)

You can either use the above two functioncalls throughout your code, or include the module SmarterLogging and use the methods directly throughout your code.

Tip: make sure that you use a globally unique naming convention for your anomaly and activity names -- this way you can pin-point what went wrong, and where it went wrong.


Anomaly logs are meant to be used for errors, exceptions and caught unexpected behavior.

require 'smarter_logging'
include SmarterLogging

# you can use a single-line log statement, with a hash of all key=value pairs
log_anomaly( :invalid_parameter , {key1: 'value 1', key2: 'value 2'}

if parameters_valid?(params)
  # do something useful

  log_activity( :user_parameters, params )

else
  # or you can use a block - this will add a key `duration` to the log line.
  log_anomaly( :user_invalid_parameters ) do |log_data|
    log_data.merge( invalid_parameter_hash )

     # some other code
  end
end

Anomaly logs are meant to be used for reporting on expected behavior.

require 'smarter_logging'
include SmarterLogging

# you can use a single-line log statement, with a hash of all key=value pairs
log_activity( :user_signed_up, {user_id: current_user.id} )
#=> time=2017-01-30T23:15:20.689Z env=development activity=user_signed_up user_id=123

# or you can use a block - this will add a key `duration` to the log line.
log_activity( :user_updated ) do |log_data|
  begin
    # update some values in user record here

    log_data[:result] = :sucess
  rescue => e
    log_data[:error_message] = e.message
    log_data[:result] = :failure
  end
end

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/Tilo Sloboda/smarter_logging. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.