fix(queues): skip unsampled optional telemetry

Co-Authored-By: Codex <noreply@example.com>

Author: solnic

sentry-rails/spec/active_job/test_adapter_spec.rb

@@ -32,6 +32,30 @@
     end
   end
 
+  context "when the transaction is unsampled" do
+    let(:configure_sentry) { proc { |config| config.traces_sample_rate = 0.0 } }
+
+    it "enqueues and performs without encoding optional body size" do
+      performed_arguments = []
+      recording_job = job_fixture do
+        define_method(:perform) { |argument| performed_arguments << argument }
+      end
+      serializations = 0
+      serializer = TracePoint.new(:call) do |call|
+        serializations += 1 if call.self.equal?(JSON) && call.method_id == :generate
+      end
+
+      serializer.enable do
+        within_parent_transaction { recording_job.perform_later("hello") }
+        drain
+      end
+
+      expect(performed_arguments).to eq(["hello"])
+      expect(serializations).to eq(0)
+      expect(transactions).to be_empty
+    end
+  end
+
   context "when tracing is disabled" do
     it "reports job errors without messaging.message.body.size" do
       expect do

sentry-ruby/lib/sentry/job_extensions/consumer.rb

@@ -51,9 +51,11 @@ def start_transaction(scope, job, trace_headers: nil, payload: nil, always_conti
         end
         return unless transaction
 
-        set_messaging_data(transaction, resolve(messaging_data).reject { |_key, value| value.nil? })
-        set_messaging_data(transaction, registry.call(extension, :messaging_data, job))
-        set_retry_count(transaction, extension, job, default: default_retry_count)
+        if transaction.sampled
+          set_messaging_data(transaction, resolve(messaging_data).reject { |_key, value| value.nil? })
+          set_messaging_data(transaction, registry.call(extension, :messaging_data, job))
+          set_retry_count(transaction, extension, job, default: default_retry_count)
+        end
 
         scope.set_span(transaction)
         transaction

sentry-ruby/lib/sentry/job_extensions/producer.rb

@@ -47,7 +47,7 @@ def with_span(job, description:, messaging_data: {}, default_messaging_data: {},
         span_description = registry.call(extension, :publish_description, job) || description
 
         Sentry.with_child_span(op: OP_NAME, description: span_description) do |span|
-          if span
+          if span && span.sampled
             span_origin = registry.call(extension, :span_origin, job) || origin
             span.set_origin(span_origin) if span_origin
 

sentry-sidekiq/spec/sentry/sidekiq/sentry_context_middleware_spec.rb

@@ -50,6 +50,31 @@
     expect(transport.events.last.contexts.dig(:trace, :trace_id)).to eq(trace_id)
   end
 
+  it "propagates unsampled jobs without serializing optional telemetry" do
+    perform_basic_setup { |config| config.traces_sample_rate = 0.0 }
+    parent = Sentry.start_transaction(name: "enqueue", op: "test")
+    Sentry.get_current_scope.set_span(parent)
+    job = { "jid" => "unsampled", "class" => "HappyWorker", "queue" => "default", "args" => [] }
+    serializations = 0
+    serializer = TracePoint.new(:call) do |call|
+      serializations += 1 if call.self.equal?(Sidekiq) && call.method_id == :dump_json
+    end
+    performed = false
+
+    serializer.enable do
+      Sentry::Sidekiq::SentryContextClientMiddleware.new.call(HappyWorker, job, "default", nil) { true }
+      described_class.new.call(HappyWorker.new, job, "default") do
+        performed = true
+        Sentry.capture_message("unsampled job")
+      end
+    end
+
+    expect(performed).to be(true)
+    expect(serializations).to eq(0)
+    expect(job["trace_propagation_headers"].keys).to include("sentry-trace", "baggage")
+    expect(transport.events.last.contexts.dig(:trace, :trace_id)).to eq(parent.trace_id)
+  end
+
   context "with tracing enabled" do
     before do
       perform_basic_setup { |config| config.traces_sample_rate = 1.0 }