Mongoid monkey-patching

initializer-monkey-patch.rb

# Monkey-patch the mongo ruby driver to expose socket information so that we can
# interrogate it for port information
module Mongo
  class Pool
    def sockets
      @sockets
    end
  end
end

# Add a method which will detect OperationTimeout exceptions and reconnect
# plus output useful logging information
module Mongoid
  module Collections

    module Retry

      def retry_on_connection_timeout
        retries = 0
        begin
          yield
        rescue Mongo::OperationTimeout => ex
          retries += 1
          raise ex if retries > Mongoid.max_retries_on_connection_failure
          Rails.logger.info("MONGODB #{Mongoid.database.name} OperationTimeout exception encountered on connection #{Mongoid.database.connection.primary_pool.sockets.first.addr[1]}") if defined?(Rails)
          Mongoid.reconnect!
          Rails.logger.info("MONGODB #{Mongoid.database.name} Reconnected with #{Mongoid.database.connection.primary_pool.sockets.first.addr[1]}") if defined?(Rails)
          retry
        end
      end
    end
  end
end


module Mongoid
  module Collections

    # This class wraps the MongoDB master database.
    class Master
      include Mongoid::Collections::Retry

      attr_reader :collection

      # Monkey patch the original method to include the connection timeout situation
      Operations::ALL.each do |name|
        define_method(name) do |*args|
          retry_on_connection_failure do
            # This is the new line that was added
            retry_on_connection_timeout do
              collection.send(name, *args)
            end
          end
        end
      end
    end
  end
end