Influxer
Influxer provides an ActiveRecord-style way to work with InfluxDB with many useful features, such as:
Installation
Adding to a gem:
# my-cool-gem.gemspec
Gem::Specification.new do |spec|
# ...
spec.add_dependency "influxer", ">= 1.2.0"
# ...
end
Or adding to your project:
# Gemfile
gem "influxer", "~> 1.2"
Usage
Metrics classes
To query InfluxDB or write to it, you should define a metrics class first. Each metrics class represents a measurement/series (or multiple related measurements):
class VisitsMetrics < Influxer::Metrics
# Define tags...
tags :account_id, :page_id
# ...and attributes
attributes :user_id, :browser
end
Querying
Now you can use your metrics classes in a similar way to Active Record models to build queries. For example:
VisitsMetrics.select(:account_id, :user_id).where(page_id: /^home\/.*/)
Influxer provides special query methods for dealing with time series:
- Group by time:
Metrics.time(:hour) => # select * ... group by time(1h)
. - Select only points for the last hour/minute/whatever:
Metrics.past(:day) => # select * ... where time > now() - 1d
. - Select only points since the specified time:
Metrics.since(Time.utc(2014,12,31)) => # select * ... where time > 1419984000s
. - and more.
See our Wiki for more.
Scopes support
You can define scopes to re-use query conditions:
class Metrics < Influxer::Metrics
tags :account_id
attributes :value
default_scope -> { time(:hour).limit(1000) }
scope :unlimited, -> { limit(nil) }
scope :by_account, ->(id) { where(account_id: id) if id.present? }
end
Metrics.by_account(1)
# => select * from "metrics" group by time(1h) where account_id=1 limit 1000
Metrics.unlimited.by_account(1).time(:week)
# => select * from "metrics" group by time(1w) where account_id=1
Active Record integration
You can association metrics with Active Record models:
class UserVisits < Influxer::Metrics
end
class User < ActiveRecord::Base
has_metrics :visits
end
user = User.find(1)
user.visits.write(page_id: "home")
#=> < creates point {user_id: 1, page_id: 'home'} in 'user_visits' series >
user.visits.where(page_id: "home")
#=> select * from user_visits where page_id='home'
Find more on Wiki.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/palkan/influxer.
License
The gem is available as open source under the terms of the MIT License.