Add event when a process has a new heartbeat

lib/sidekiq.rb

@@ -28,6 +28,7 @@ module Sidekiq
       startup: [],
       quiet: [],
       shutdown: [],
+      heartbeat: [],
     },
     dead_max_jobs: 10_000,
     dead_timeout_in_seconds: 180 * 24 * 60 * 60 # 6 months

lib/sidekiq/launcher.rb

@@ -94,15 +94,19 @@ module Sidekiq
         end
         fails = procd = 0
 
-        _, _, _, msg = Sidekiq.redis do |conn|
+        _, exists, _, _, msg = Sidekiq.redis do |conn|
           conn.multi do
             conn.sadd('processes', key)
+            conn.exists(key)
             conn.hmset(key, 'info', json, 'busy', Processor::WORKER_STATE.size, 'beat', Time.now.to_f, 'quiet', @done)
             conn.expire(key, 60)
             conn.rpop("#{key}-signals")
           end
         end
 
+        # first heartbeat or recovering from an outage and need to reestablish our heartbeat
+        fire_event(:heartbeat) if !exists
+
         return unless msg
 
         if JVM_RESERVED_SIGNALS.include?(msg)

test/test_launcher.rb

@@ -15,8 +15,6 @@ class TestLauncher < Sidekiq::Test
 
     describe 'heartbeat' do
       before do
-        uow = Object.new
-
         @mgr = new_manager(options)
         @launcher = Sidekiq::Launcher.new(options)
         @launcher.manager = @mgr
@@ -31,6 +29,18 @@ class TestLauncher < Sidekiq::Test
         $0 = @proctitle
       end
 
+      it 'fires new heartbeat events' do
+        i = 0
+        Sidekiq.on(:heartbeat) do
+          i += 1
+        end
+        assert_equal 0, i
+        @launcher.heartbeat('identity', heartbeat_data, Sidekiq.dump_json(heartbeat_data))
+        assert_equal 1, i
+        @launcher.heartbeat('identity', heartbeat_data, Sidekiq.dump_json(heartbeat_data))
+        assert_equal 1, i
+      end
+
       describe 'when manager is active' do
         before do
           Sidekiq::CLI::PROCTITLES << proc { "xyz" }