Gemfile

source 'https://rubygems.org'

gem 'mongo'
gem 'bson_ext'

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    bson (1.11.1)
    bson (1.11.1-java)
    bson_ext (1.11.1)
      bson (~> 1.11.1)
    mongo (1.11.1)
      bson (= 1.11.1)

PLATFORMS
  java
  ruby

DEPENDENCIES
  bson_ext
  mongo

mongo.rb

require 'rubygems'
require 'bundler/setup'
Bundler.require(:default)

class MongoClient
  def initialize
    @mongo_client = Mongo::MongoClient.new 'localhost',30999, pool_size: 3, pool_timeout:1, op_timeout:1, connect_timeout:1, read: :secondary_preferred
      #:secondary_preferred
    @mongo_database = @mongo_client['mongodb_outage_test']
  end

  def fetch_data
    attempts = 1
    begin
      @mongo_database['data'].find(_id: rand(100_000)).first
    rescue Mongo::OperationTimeout, Mongo::OperationFailure => e
      @mongo_client.ping
      attempts+=1
      sleep 0.25
      retry if attempts < 3
      puts "Surrender on attempt #{attempts}"
      raise
    end
  end

  def run
    while true
      begin
        puts "#{Time.now} #{fetch_data['_id']}"
      rescue Interrupt
        puts "quit!"
        break
      rescue StandardError => e
        puts "#{Time.now} EXCEPTION: #{e.class}: #{e}"
      end
      sleep 0.5
    end
  end
end

MongoClient.new.run