Mercy

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

Add Mercy to your Gemfile and bundle install:
```
gem 'mercy'
```
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

Add a route to your controller

  scope path: 'health-check', controller: :health_check do
    get '/status' => :status
    get '/late-status' => :late_status
  end

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

Run the server and hit the health-check routes

 wget http://localhost:3000/health-check/status
 wget http://localhost:3000/health-check/late-status

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" } }