code: def test_consecutive_failures(serve_instance):
      # Test that the health check must fail N times before being restarted.
  
      counter = ray.remote(Counter).remote()
  
      @serve.deployment(health_check_period_s=1)
      class ChronicallyUnhealthy:
          def __init__(self):
              self._actor_id = (
                  ray.get_runtime_context().current_actor._actor_id
              )
              self._should_fail = False
  
          def check_health(self):
              if self._should_fail:
                  ray.get(counter.inc.remote())
                  raise Exception("intended to fail")
  
          def set_should_fail(self):
              self._should_fail = True
              return self._actor_id
  
          def __call__(self, *args):
              return self._actor_id
  
      h = serve.run(ChronicallyUnhealthy.bind())
  
      def check_fails_3_times():
          original_actor_id = h.set_should_fail.remote().result()
  
          # Wait until a new actor is started.
          wait_for_condition(
              lambda: h.remote().result() != original_actor_id
          )
  
          # Check that the health check failed N times before replica was killed.
          assert (
              ray.get(counter.get.remote())
              == REPLICA_HEALTH_CHECK_UNHEALTHY_THRESHOLD
          )
  
      # Run the check twice to see that the counter gets reset after a
      # replica is killed.
      check_fails_3_times()
      ray.get(counter.reset.remote())
      check_fails_3_times()
  
imports: import pytest
  import ray
  from ray import serve
  from ray._private.test_utils import wait_for_condition
  from ray.exceptions import RayError
  from ray.serve._private.common import DeploymentStatus
  from ray.serve._private.constants import REPLICA_HEALTH_CHECK_UNHEALTHY_THRESHOLD, SERVE_DEFAULT_APP_NAME
label_desc: Use image node_id 8 for calling a global function with example usage: test_consecutive_failures(serve_instance) and returns: self, self