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
      #: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 => 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}"
      end
      sleep 0.5
    end
  end
end

MongoClient.new.run