void update(const TaskStatus& status)
  {
    CHECK_EQ(SUBSCRIBED, state);

    LOG(INFO)
      << "Task " << status.task_id().value()
      << " is in state " << TaskState_Name(status.state())
      << (status.has_message() ? " with message: " + status.message() : "");

    if (status.has_uuid()) {
      Call call;
      call.set_type(Call::ACKNOWLEDGE);

      CHECK(framework.has_id());
      call.mutable_framework_id()->CopyFrom(framework.id());

      Call::Acknowledge* acknowledge = call.mutable_acknowledge();
      acknowledge->mutable_agent_id()->CopyFrom(status.agent_id());
      acknowledge->mutable_task_id()->CopyFrom(status.task_id());
      acknowledge->set_uuid(status.uuid());

      mesos->send(call);
    }

    if (status.state() == TaskState::TASK_KILLED ||
        status.state() == TaskState::TASK_LOST ||
        status.state() == TaskState::TASK_FAILED ||
        status.state() == TaskState::TASK_ERROR) {
      ++metrics.abnormal_terminations;
    }
  }
// This test verifies that the scheduler will receive a `BadRequest` response
// when it tries to acknowledge a status update with a malformed UUID.
TEST_P(SchedulerHttpApiTest, MalformedUUID)
{
  Try<Owned<cluster::Master>> master = StartMaster();
  ASSERT_SOME(master);

  // Retrieve the parameter passed as content type to this test.
  const string contentType = GetParam();

  process::http::Headers headers = createBasicAuthHeaders(DEFAULT_CREDENTIAL);
  headers["Accept"] = contentType;
  v1::FrameworkID frameworkId;
  string streamId;

  // Subscribe once to get a valid stream ID.
  {
    Call call;
    call.set_type(Call::SUBSCRIBE);

    Call::Subscribe* subscribe = call.mutable_subscribe();
    subscribe->mutable_framework_info()->CopyFrom(v1::DEFAULT_FRAMEWORK_INFO);

    Future<Response> response = process::http::streaming::post(
        master.get()->pid,
        "api/v1/scheduler",
        headers,
        serialize(call, contentType),
        contentType);

    AWAIT_EXPECT_RESPONSE_STATUS_EQ(OK().status, response);
    ASSERT_EQ(Response::PIPE, response.get().type);
    ASSERT_TRUE(response.get().headers.contains("Mesos-Stream-Id"));

    streamId = response.get().headers.at("Mesos-Stream-Id");

    Option<Pipe::Reader> reader = response.get().reader;
    ASSERT_SOME(reader);

    auto deserializer = lambda::bind(
        &SchedulerHttpApiTest::deserialize, this, contentType, lambda::_1);

    Reader<Event> responseDecoder(Decoder<Event>(deserializer), reader.get());

    Future<Result<Event>> event = responseDecoder.read();
    AWAIT_READY(event);
    ASSERT_SOME(event.get());

    // Check that the event type is subscribed and the framework ID is set.
    ASSERT_EQ(Event::SUBSCRIBED, event.get().get().type());

    frameworkId = event.get().get().subscribed().framework_id();
    EXPECT_NE("", frameworkId.value());
  }

  // Make an acknowledge call with a malformed UUID. This should result in a
  // `BadResponse`.
  {
    headers["Mesos-Stream-Id"] = streamId;

    Call call;
    call.set_type(Call::ACKNOWLEDGE);

    // Set the framework ID in the subscribe call.
    call.mutable_framework_id()->CopyFrom(frameworkId);

    Call::Acknowledge* acknowledge = call.mutable_acknowledge();
    acknowledge->mutable_task_id()->set_value("task-id");
    acknowledge->mutable_agent_id()->set_value("agent-id");

    // Set a malformed uuid.
    acknowledge->set_uuid("bad-uuid");

    Future<Response> response = process::http::post(
        master.get()->pid,
        "api/v1/scheduler",
        headers,
        serialize(call, contentType),
        contentType);

    AWAIT_EXPECT_RESPONSE_STATUS_EQ(BadRequest().status, response);
    AWAIT_EXPECT_RESPONSE_BODY_EQ(
        "Failed to validate scheduler::Call: Not a valid UUID", response);
  }
}