DelayedJob BaseJob Template - With Memory Usage Logging

delayed_job_base_job.rb

class BaseJob

  def self.queue(*args)
    options = args.extract_options!
    Delayed::Job.enqueue(new(*args), options)
  end

  def initialize(*args)
    @args = args
  end

  def error(job, exception)
    raise exception if Rails.env.test?

    logger.error "#{Time.now.utc} : #{exception.class.name} : #{exception}"
    Airbrake.notify(exception)
  end

  def before(job)
    @starting_memory = fetch_memory_usage
    @starting_time = Time.now.utc
  end

  def after(job)
    @args = nil
    GC.start unless Rails.env.test?

    @finishing_memory = fetch_memory_usage
    @finishing_time = Time.now.utc
    diff = (@finishing_memory - @starting_memory).round(3)
    time_taken = (@finishing_time - @starting_time).round(1)
    job_name = (job.handler =~ /:(\w+)\n/) && $1
    memory_logger.warn "#{Time.now.utc} : #{Process.pid} : MEMORY READOUT : JOB=#{job_name}, TIME=#{time_taken}s, BEFORE=#{@starting_memory}Mb, AFTER=#{@finishing_memory}Mb, DIFF=#{diff}Mb" if diff > 0.1
  end

  def logger
    @logger ||= Logger.new(Rails.root.join('log/delayed_job.log'))
  end

  def memory_logger
    @memory_logger ||= Logger.new(Rails.root.join('log/delayed_job_memory.log'))
  end

  def fetch_memory_usage
    (`ps -o rss= -p #{Process.pid}`.chomp.to_f / 1024).round(3) rescue 0.0
  end

end