Track maximum runtime of currently running jobs (#17)

Closes #13

README.md

@@ -49,6 +49,7 @@ end
  - Number of jobs in dead set (“morgue”): `sidekiq_jobs_dead_count`
  - Active workers count: `sidekiq_active_processes`
  - Active processes count: `sidekiq_active_workers_count`
+ - Maximum runtime of currently executing jobs: `sidekiq_running_job_runtime` (useful for detection of hung jobs, segmented by queue and class name)
 
 ## Custom tags
 

lib/yabeda/sidekiq.rb

@@ -33,6 +33,8 @@ module Sidekiq
       gauge     :jobs_dead_count,      tags: [],        comment: "The number of jobs exceeded their retry count."
       gauge     :active_processes,     tags: [],        comment: "The number of active Sidekiq worker processes."
       gauge     :queue_latency,        tags: %i[queue], comment: "The queue latency, the difference in seconds since the oldest job in the queue was enqueued"
+      gauge     :running_job_runtime,  tags: %i[queue worker], aggregation: :max, unit: :seconds,
+                                       comment: "How long currently running jobs are running (useful for detection of hung jobs)"
 
       histogram :job_latency, comment: "The job latency, the difference in seconds between enqueued and running time",
                               unit: :seconds, per: :job,
@@ -59,6 +61,8 @@ module Sidekiq
           sidekiq_queue_latency.set({ queue: queue.name }, queue.latency)
         end
 
+        Yabeda::Sidekiq.track_max_job_runtime
+
         # That is quite slow if your retry set is large
         # I don't want to enable it by default
         # retries_by_queues =
@@ -105,6 +109,22 @@ def custom_tags(worker, job)
 
         worker.method(:yabeda_tags).arity.zero? ? worker.yabeda_tags : worker.yabeda_tags(*job["args"])
       end
+
+      # Hash of hashes containing all currently running jobs' start timestamps
+      # to calculate maximum durations of currently running not yet completed jobs
+      # { { queue: "default", worker: "SomeJob" } => { "jid1" => 100500, "jid2" => 424242 } }
+      attr_accessor :jobs_started_at
+
+      def track_max_job_runtime
+        now = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+        ::Yabeda::Sidekiq.jobs_started_at.each do |labels, jobs|
+          oldest_job_started_at = jobs.values.min
+          oldest_job_duration = oldest_job_started_at ? (now - oldest_job_started_at).round(3) : 0
+          Yabeda.sidekiq.running_job_runtime.set(labels, oldest_job_duration)
+        end
+      end
     end
+
+    self.jobs_started_at = Concurrent::Hash.new { |hash, key| hash[key] = Concurrent::Hash.new }
   end
 end

lib/yabeda/sidekiq/server_middleware.rb

@@ -12,6 +12,7 @@ def call(worker, job, queue)
         begin
           job_instance = ::Sidekiq::Job.new(job)
           Yabeda.sidekiq_job_latency.measure(labels, job_instance.latency)
+          Yabeda::Sidekiq.jobs_started_at[labels][job["jid"]] = start
           Yabeda.with_tags(**custom_tags) do
             yield
           end
@@ -22,6 +23,7 @@ def call(worker, job, queue)
         ensure
           Yabeda.sidekiq_job_runtime.measure(labels, elapsed(start))
           Yabeda.sidekiq_jobs_executed_total.increment(labels)
+          Yabeda::Sidekiq.jobs_started_at[labels].delete(job["jid"])
         end
       end
       # rubocop: enable Metrics/AbcSize, Metrics/MethodLength:

spec/support/jobs.rb

@@ -8,6 +8,15 @@ def perform(*_args)
   end
 end
 
+class SampleLongRunningJob
+  include Sidekiq::Worker
+
+  def perform(*_args)
+    sleep 0.05
+    "Phew, I'm done!"
+  end
+end
+
 class SampleComplexJob
   include Sidekiq::Worker
 

spec/support/sidekiq_inline_middlewares.rb

@@ -7,6 +7,7 @@ def push(job)
     return super unless Sidekiq::Testing.inline?
 
     job = Sidekiq.load_json(Sidekiq.dump_json(job))
+    job["jid"] ||= SecureRandom.hex(12)
     job_class = Sidekiq::Testing.constantize(job["class"])
     job_instance = job_class.new
     queue = (job_instance.sidekiq_options_hash || {}).fetch("queue", "default")

spec/yabeda/sidekiq_spec.rb

@@ -167,5 +167,43 @@
       expect(Yabeda.sidekiq.jobs_dead_count.values).to eq({ {} => 3 })
       expect(Yabeda.sidekiq.jobs_scheduled_count.values).to eq({ {} => 2 })
     end
+
+    it "measures maximum runtime of currently running jobs" do
+      Yabeda.sidekiq.running_job_runtime.values.clear # This is a hack
+      described_class.jobs_started_at.clear
+
+      Sidekiq::Testing.inline! do
+        workers = []
+        workers.push(Thread.new { SampleLongRunningJob.perform_async })
+        sleep 0.012 # Ruby can sleep less than requested
+        workers.push(Thread.new { SampleLongRunningJob.perform_async })
+
+        Yabeda.collectors.each(&:call)
+        expect(Yabeda.sidekiq.running_job_runtime.values).to include(
+          { queue: "default", worker: "SampleLongRunningJob" } => (be >= 0.010),
+        )
+
+        sleep 0.012 # Ruby can sleep less than requested
+        begin
+          FailingActiveJob.perform_later
+        rescue StandardError
+          nil
+        end
+        Yabeda.collectors.each(&:call)
+
+        expect(Yabeda.sidekiq.running_job_runtime.values).to include(
+          { queue: "default", worker: "SampleLongRunningJob" } => (be >= 0.020),
+          { queue: "default", worker: "FailingActiveJob" } => 0,
+        )
+
+        # When all jobs are completed, metric should respond with zero
+        workers.map(&:join)
+        Yabeda.collectors.each(&:call)
+        expect(Yabeda.sidekiq.running_job_runtime.values).to include(
+          { queue: "default", worker: "SampleLongRunningJob" } => 0,
+          { queue: "default", worker: "FailingActiveJob" } => 0,
+        )
+      end
+    end
   end
 end