log memory consumption

delayed_job.gemspec

@@ -2,6 +2,7 @@
 
 Gem::Specification.new do |spec|
   spec.add_dependency 'activesupport', ['>= 3.0', '< 6.1']
+  spec.add_dependency 'get_process_mem'
   spec.authors        = ['Brandon Keepers', 'Brian Ryckbost', 'Chris Gaffney', 'David Genord II', 'Erik Michaels-Ober', 'Matt Griffin', 'Steve Richert', 'Tobias Lütke']
   spec.description    = 'Delayed_job (or DJ) encapsulates the common pattern of asynchronously executing longer tasks in the background. It is a direct extraction from Shopify where the job table is responsible for a multitude of core tasks.'
   spec.email          = ['[email protected]']

lib/delayed/worker.rb

@@ -6,6 +6,7 @@
 require 'active_support/core_ext/hash/indifferent_access'
 require 'logger'
 require 'benchmark'
+require 'get_process_mem'
 
 module Delayed
   class Worker # rubocop:disable ClassLength
@@ -225,12 +226,14 @@ def work_off(num = 100)
     end
 
     def run(job)
-      job_say job, 'RUNNING'
+      mem_monitor = GetProcessMem.new
+      start_mem = mem_monitor.mb
+      job_say job, format('RUNNING, mem %<mem>.1f Mb', mem: start_mem)
       runtime = Benchmark.realtime do
         Timeout.timeout(max_run_time(job).to_i, WorkerTimeout) { job.invoke_job }
         job.destroy
       end
-      job_say job, format('COMPLETED after %.4f', runtime)
+      job_say job, format('COMPLETED after %<runtime>.4f, mem leak %<memleak>.1f Mb', runtime: runtime, memleak: mem_monitor.mb - start_mem)
       return true # did work
     rescue DeserializationError => error
       job_say job, "FAILED permanently with #{error.class.name}: #{error.message}", 'error'