Mercy

Code Climate Test Coverage Issue Count Gem Version

mercy

This gem tries to make server monitoring easier and more reliable by adding an easly configurable report and making it avaliable in a controller

Yard Documentation

https://www.rubydoc.info/gems/mercy/1.6.0

Getting started

  1. Add Mercy to your Gemfile and bundle install:

    gem 'mercy'
    
  2. Include in your health check controller passing the configuration to fetch your Documents with error and render the report

  class HealthCheckController < ApplicationController
    include Mercy

    status_report :failures, clazz: Document
    status_report :failures, clazz: Schedules, on: :schedules
    status_report :delays, clazz: Schedules, scope: :late, on: :schedules
    status_report :'documents.count', clazz: Document, scope: :active, type: Mercy::Range, minimum: 100
    status_report :'documents.errors', clazz: Document, scope: :'active.with_error', type: :range, maximum: 1000

    def status
      render_status
    end

    def late_status
      render_status(:schedules)
    end
  end
  1. Add a route to your controller
  scope path: 'health-check', controller: :health_check do
    get '/status' => :status
    get '/late-status' => :late_status
  end
  1. Set the correct options on your status report to achieve a perfect report
    • clazz: Class of the object that might contain error
    • period: default search period (default: 1 day)
    • on: report bucket (default: :default)
    • type: report type (error, range or other custom report)

Remembering that each report may have its onw parameters

  • Mercy::Error
    • scope: scope to be fetched when trying to find objects with error (default: :with_error)
    • external_key: column to be exposed as id for the objects with error
    • threshold: default report threshold (default: 0.02)
    • base_scope: scope to be universal sample
    • uniq: when the output ids should not be repeated
    • limit: limit of ids to be outputed
  • Mercy::Range
    • scope: scope of the query to be counted
    • maximum: max value accepted in the range
    • minimum: minimum value accepted in the range
  1. Run the server and hit the health-check routes
 wget http://localhost:3000/health-check/status
 wget http://localhost:3000/health-check/late-status
  1. Customize your request for multiple reports

    wget http://localhost:3000/health-check/status?period=3.days&threshold=0.005
    wget http://localhost:3000/health-check/late-status?period=1.hours&threshold=0.1
    
    1. Use the status json to understand what is wrong json { "status": "error", "failures": { "ids": [10, 14], "percentage": 0.5, "status": "error" }, "delays": { "ids": [12], "percentage": 0.001, "status": "ok" } }