sampler.rb in karafka-web-0.2.3

- old
+ new

@@ -58,11 +58,11 @@
 
               process: {
                 started_at: @started_at,
                 name: process_name,
                 status: ::Karafka::App.config.internal.status.to_s,
-                listeners: Karafka::Server.listeners.count,
+                listeners: listeners,
                 concurrency: concurrency,
                 memory_usage: memory_usage,
                 memory_total_usage: memory_total_usage,
                 memory_size: memory_size,
                 cpu_count: cpu_count,
@@ -74,11 +74,11 @@
                 ruby: ruby_version,
                 karafka: ::Karafka::VERSION,
                 waterdrop: ::WaterDrop::VERSION
               },
 
-              stats: Karafka::Server.jobs_queue.statistics.merge(
+              stats: jobs_queue_statistics.merge(
                 utilization: utilization
               ).merge(total: @counters),
 
               consumer_groups: @consumer_groups,
               jobs: jobs.values
@@ -110,10 +110,16 @@
             # We divide by 1_000 to convert from milliseconds
             # We multiply by 100 to have it in % scale
             times[:total].sum / 1_000 / concurrency / timefactor * 100
           end
 
+          # @return [Integer] number of listeners
+          def listeners
+            # This can be zero before the server starts
+            Karafka::Server.listeners&.count.to_i
+          end
+
           # @return [String] Unique process name
           def process_name
             @process_name ||= "#{Socket.gethostname}:#{::Process.pid}:#{SecureRandom.hex(6)}"
           end
 
@@ -138,9 +144,15 @@
                 .last
                 .to_i
             else
               0
             end
+          end
+
+          # @return [Hash] job queue statistics
+          def jobs_queue_statistics
+            # We return empty stats in case jobs queue is not yet initialized
+            Karafka::Server.jobs_queue&.statistics || { busy: 0, enqueued: 0 }
           end
 
           # Total memory used in the OS
           def memory_total_usage
             case RUBY_PLATFORM