Fix redis-server stoping in linux (#6296)

* Cleanup test_calling_start_ray_head

* Kill redis-server with args instead of comm

In linux, ps -o pid,comm output just redis-server instead of the
full executable path

python/ray/scripts/scripts.py

@@ -444,7 +444,7 @@ def stop(force, verbose):
         ["plasma_store", True],
         ["raylet_monitor", True],
         ["monitor.py", False],
-        ["redis-server", True],
+        ["redis-server", False],
         ["default_worker.py", False],  # Python worker.
         ["ray::", True],  # Python worker.
         ["org.ray.runtime.runner.worker.DefaultWorker", False],  # Java worker.

python/ray/tests/conftest.py

@@ -162,6 +162,11 @@ def call_ray_start(request):
     # Kill the Ray cluster.
     subprocess.check_output(["ray", "stop"])
 
+@pytest.fixture
+def call_ray_stop_only():
+    yield
+    subprocess.check_output(["ray", "stop"])
+
 
 @pytest.fixture()
 def two_node_cluster():

python/ray/tests/test_multi_node.py

@@ -321,7 +321,7 @@ print("success")
         process_handle.kill()
 
 
-def test_calling_start_ray_head():
+def test_calling_start_ray_head(call_ray_stop_only):
     # Test that we can call ray start with various command line
     # parameters. TODO(rkn): This test only tests the --head code path. We
     # should also test the non-head node code path.