Historedis

Historedis is a gem that lets you store counts of variables in Redis, all of which are stored in a certain namespace (internally a hash in Redis) which you can then query to get a distribution.

Installation

Add this line to your application's Gemfile:

gem 'historedis'

And then execute:

$ bundle

Or install it yourself as:

$ gem install historedis

Usage

Initializing a Historedis Instance

HISTOREDIS = HistoRedis.new

If you want to specify a Redis URL,

HISTOREDIS = HistoRedis.new(ENV['REDIS_URL'])

Incrementing a variable

Say you want to track the number of API requests made to an external service per request ID, use this API:

HISTOREDIS.increment('external_service.api.count', 'request-id-1')

If you want to keep the data for a certain amount of time, you can do this:

HISTOREDIS.increment('external_service.api.count', 'request-id-1', keep_data_for: 12.hours)

Distribution

Say you have made the following increment API calls:

HISTOREDIS.increment('external_service.api.count', 'request-id-1')
HISTOREDIS.increment('external_service.api.count', 'request-id-1')
HISTOREDIS.increment('external_service.api.count', 'request-id-2')
HISTOREDIS.increment('external_service.api.count', 'request-id-3')

Calling Historedis.distribution('external_service.api.count') will return:

{ 2 => 1, 1 => 2 }

What this distribution indicates that there are two requests which made 1 call to the external service, (request-id-2, request-id-3 respectively) and one request which made 2 calls to the external service viz. request-id-1

Development

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.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/envoy/historedis. 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.

License

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

Code of Conduct

Everyone interacting in the Historedis project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.