Custodian

Custodian is a lightweight resource monitor that makes it really easy and really awesome to sample metrics.

Usage

Server

Start Custodian and configure it to expose its metrics on port 5100:

$ custodian --port=5100

Samplers

Custodian aggregates metrics from samplers, and ships with samplers for popular figures such as logged in users and load averages. That's interesting and all, but custom samplers are all the rage.

class RegisteredUsers < Custodian::Samplers::Sampler
  describe "Registered users"

  def self.sample
    Users.count
  end
end

You can load your own samplers with the --samplers option.

$ custodian --samplers=~/.samplers

Clients

Unless you're crazy about JSON, you'll want to consume Custodian's API with a client. Unfortunately, there are no clients for Custodian yet — you should make one!