[Client] Add ray.client().disconnect() (#16021)

doc/source/namespaces.rst

@@ -19,34 +19,33 @@ Named actors are only accessible within their namespaces.
 
 .. code-block:: python
 
-    import
+    import ray
 
     @ray.remote
     class Actor:
       pass
 
     # Job 1 creates two actors, "orange" and "purple" in the "colors" namespace.
-    ray.client().namespace("colors").connect()
-    Actor.options(name="orange", lifetime="detached")
-    Actor.options(name="purple", lifetime="detached")
-    ray.util.disconnect()
+    with ray.client().namespace("colors").connect():
+      Actor.options(name="orange", lifetime="detached")
+      Actor.options(name="purple", lifetime="detached")
 
     # Job 2 is now connecting to a different namespace.
-    ray.client().namespace("fruits").connect()
-    # This fails because "orange" was defined in the "colors" namespace.
-    ray.get_actor("orange")
-    # This succceeds because the name "orange" is unused in this namespace.
-    Actor.options(name="orange", lifetime="detached")
-    Actor.options(name="watermelon", lifetime="detached")
-    ray.util.disconnect()
+    with ray.client().namespace("fruits").connect():
+      # This fails because "orange" was defined in the "colors" namespace.
+      ray.get_actor("orange")
+      # This succceeds because the name "orange" is unused in this namespace.
+      Actor.options(name="orange", lifetime="detached")
+      Actor.options(name="watermelon", lifetime="detached")
 
     # Job 3 connects to the original "colors" namespace
-    ray.client().namespace("colors").connect()
+    context = ray.client().namespace("colors").connect()
     # This fails because "watermelon" was in the fruits namespace.
     ray.get_actor("watermelon")
     # This returns the "orange" actor we created in the first job, not the second.
     ray.get_actor("orange")
-    ray.util.disconnect()
+    context.disconnect()
+    # We are manually managing the scope of the connection in this example. 
          
 
 Anonymous namespaces
@@ -58,22 +57,22 @@ will not have access to actors in other namespaces.
 
 .. code-block:: python
 
-    import
+    import ray
 
     @ray.remote
     class Actor:
       pass
 
     # Job 1 connects to an anonymous namespace by default
-    ray.client().connect()
+    ctx = ray.client().connect()
     Actor.options(name="my_actor", lifetime="detached")
-    ray.util.disconnect()
+    ctx.disconnect()
 
     # Job 2 connects to an _different_ anonymous namespace by default
-    ray.client().connect()
+    ctx = ray.client().connect()
     # This succeeds because the second job is in its own namespace.
     Actor.options(name="my_actor", lifetime="detached")
-    ray.util.disconnect()
+    ctx.disconnect()
 
 .. note::
 

python/ray/client_builder.py

@@ -3,6 +3,7 @@ import importlib
 import logging
 from dataclasses import dataclass
 from urllib.parse import urlparse
+import sys
 from typing import Any, Dict, Optional, Tuple
 
 from ray.ray_constants import RAY_ADDRESS_ENVIRONMENT_VARIABLE
@@ -13,17 +14,44 @@ logger = logging.getLogger(__name__)
 
 
 @dataclass
-class ClientInfo:
+class ClientContext:
     """
-    Basic information of the remote server for a given Ray Client connection.
+    Basic context manager for a ClientBuilder connection.
     """
     dashboard_url: Optional[str]
     python_version: str
     ray_version: str
     ray_commit: str
-    protocol_version: str
+    protocol_version: Optional[str]
     _num_clients: int
 
+    def __enter__(self) -> "ClientContext":
+        return self
+
+    def __exit__(self, *exc) -> None:
+        self.disconnect()
+
+    def disconnect(self) -> None:
+        """
+        Disconnect Ray. This either disconnects from the remote Client Server
+        or shuts the current driver down.
+        """
+        if ray.util.client.ray.is_connected():
+            # This is only a client connected to a server.
+            ray.util.client_connect.disconnect()
+            ray._private.client_mode_hook._explicitly_disable_client_mode()
+        elif ray.worker.global_worker.node is None:
+            # Already disconnected.
+            return
+        elif ray.worker.global_worker.node.is_head():
+            logger.debug(
+                "The current Ray Cluster is scoped to this process. "
+                "Disconnecting is not possible as it will shutdown the "
+                "cluster.")
+        else:
+            # This is only a driver connected to an existing cluster.
+            ray.shutdown()
+
 
 class ClientBuilder:
     """
@@ -56,7 +84,7 @@ class ClientBuilder:
         self._job_config.set_ray_namespace(namespace)
         return self
 
-    def connect(self) -> ClientInfo:
+    def connect(self) -> ClientContext:
         """
         Begin a connection to the address passed in via ray.client(...).
 
@@ -69,7 +97,7 @@ class ClientBuilder:
             self.address, job_config=self._job_config)
         dashboard_url = ray.get(
             ray.remote(ray.worker.get_dashboard_url).remote())
-        return ClientInfo(
+        return ClientContext(
             dashboard_url=dashboard_url,
             python_version=client_info_dict["python_version"],
             ray_version=client_info_dict["ray_version"],
@@ -79,11 +107,19 @@ class ClientBuilder:
 
 
 class _LocalClientBuilder(ClientBuilder):
-    def connect(self) -> ClientInfo:
+    def connect(self) -> ClientContext:
         """
         Begin a connection to the address passed in via ray.client(...).
         """
-        return ray.init(address=self.address, job_config=self._job_config)
+        connection_dict = ray.init(
+            address=self.address, job_config=self._job_config)
+        return ClientContext(
+            dashboard_url=connection_dict["webui_url"],
+            python_version="{}.{}.{}".format(
+                sys.version_info[0], sys.version_info[1], sys.version_info[2]),
+            ray_version=ray.__version__,
+            ray_commit=ray.__commit__,
+            protocol_version=None)
 
 
 def _split_address(address: str) -> Tuple[str, str]:
@@ -103,7 +139,11 @@ def _get_builder_from_address(address: Optional[str]) -> ClientBuilder:
         return _LocalClientBuilder(None)
     if address is None:
         try:
-            with open("/tmp/ray/current_cluster", "r") as f:
+            # NOTE: This is not placed in `Node::get_temp_dir_path`, because
+            # this file is accessed before the `Node` object is created.
+            cluster_file = os.path.join(ray._private.utils.get_user_temp_dir(),
+                                        "ray_current_cluster")
+            with open(cluster_file, "r") as f:
                 address = f.read()
                 print(address)
         except FileNotFoundError:

python/ray/tests/test_client_builder.py

@@ -90,15 +90,14 @@ print(ray.get_runtime_context().namespace)
 
 def test_connect_to_cluster(ray_start_regular_shared):
     server = ray_client_server.serve("localhost:50055")
-    client_info = ray.client("localhost:50055").connect()
-
-    assert client_info.dashboard_url == ray.worker.get_dashboard_url()
-    python_version = ".".join([str(x) for x in list(sys.version_info)[:3]])
-    assert client_info.python_version == python_version
-    assert client_info.ray_version == ray.__version__
-    assert client_info.ray_commit == ray.__commit__
-    protocol_version = ray.util.client.CURRENT_PROTOCOL_VERSION
-    assert client_info.protocol_version == protocol_version
+    with ray.client("localhost:50055").connect() as client_context:
+        assert client_context.dashboard_url == ray.worker.get_dashboard_url()
+        python_version = ".".join([str(x) for x in list(sys.version_info)[:3]])
+        assert client_context.python_version == python_version
+        assert client_context.ray_version == ray.__version__
+        assert client_context.ray_commit == ray.__commit__
+        protocol_version = ray.util.client.CURRENT_PROTOCOL_VERSION
+        assert client_context.protocol_version == protocol_version
 
     server.stop(0)
     subprocess.check_output("ray stop --force", shell=True)
@@ -180,3 +179,37 @@ assert len(ray._private.services.find_redis_address()) == 1
         retry_interval_ms=1000)
     p1.kill()
     subprocess.check_output("ray stop --force", shell=True)
+
+
+def test_disconnect(call_ray_stop_only):
+    subprocess.check_output(
+        "ray start --head --ray-client-server-port=25555", shell=True)
+    with ray.client("localhost:25555").namespace("n1").connect():
+        # Connect via Ray Client
+        namespace = ray.get_runtime_context().namespace
+        assert namespace == "n1"
+        assert ray.util.client.ray.is_connected()
+
+    with pytest.raises(ray.exceptions.RaySystemError):
+        ray.put(300)
+
+    with ray.client(None).namespace("n1").connect():
+        # Connect Directly via Driver
+        namespace = ray.get_runtime_context().namespace
+        assert namespace == "n1"
+        assert not ray.util.client.ray.is_connected()
+
+    with pytest.raises(ray.exceptions.RaySystemError):
+        ray.put(300)
+
+    ctx = ray.client("localhost:25555").namespace("n1").connect()
+    # Connect via Ray Client
+    namespace = ray.get_runtime_context().namespace
+    assert namespace == "n1"
+    assert ray.util.client.ray.is_connected()
+    ctx.disconnect()
+    # Check idempotency
+    ctx.disconnect()
+
+    with pytest.raises(ray.exceptions.RaySystemError):
+        ray.put(300)

python/ray/tests/test_client_proxy.py

@@ -85,14 +85,12 @@ def test_multiple_clients_use_different_drivers(call_ray_start):
     """
     Test that each client uses a separate JobIDs and namespaces.
     """
-    ray.client("localhost:25001").connect()
-    job_id_one = ray.get_runtime_context().job_id
-    namespace_one = ray.get_runtime_context().namespace
-    ray.util.disconnect()
-    ray.client("localhost:25001").connect()
-    job_id_two = ray.get_runtime_context().job_id
-    namespace_two = ray.get_runtime_context().namespace
-    ray.util.disconnect()
+    with ray.client("localhost:25001").connect():
+        job_id_one = ray.get_runtime_context().job_id
+        namespace_one = ray.get_runtime_context().namespace
+    with ray.client("localhost:25001").connect():
+        job_id_two = ray.get_runtime_context().job_id
+        namespace_two = ray.get_runtime_context().namespace
 
     assert job_id_one != job_id_two
     assert namespace_one != namespace_two

python/ray/tests/test_runtime_env_complicated.py

@@ -62,14 +62,15 @@ def conda_envs():
 
 check_remote_client_conda = """
 import ray
-ray.client("localhost:24001").env({{"conda" : "tf-{tf_version}"}}).connect()
+context = ray.client("localhost:24001").env({{"conda" : "tf-{tf_version}"}}).\\
+connect()
 @ray.remote
 def get_tf_version():
     import tensorflow as tf
     return tf.__version__
 
 assert ray.get(get_tf_version.remote()) == "{tf_version}"
-ray.util.disconnect()
+context.disconnect()
 """
 
 
@@ -96,9 +97,8 @@ def test_client_tasks_and_actors_inherit_from_driver(conda_envs,
 
     tf_versions = ["2.2.0", "2.3.0"]
     for i, tf_version in enumerate(tf_versions):
-        try:
-            runtime_env = {"conda": f"tf-{tf_version}"}
-            ray.client("localhost:24001").env(runtime_env).connect()
+        runtime_env = {"conda": f"tf-{tf_version}"}
+        with ray.client("localhost:24001").env(runtime_env).connect():
             assert ray.get(get_tf_version.remote()) == tf_version
             actor_handle = TfVersionActor.remote()
             assert ray.get(actor_handle.get_tf_version.remote()) == tf_version
@@ -108,9 +108,6 @@ def test_client_tasks_and_actors_inherit_from_driver(conda_envs,
             other_tf_version = tf_versions[(i + 1) % 2]
             run_string_as_driver(
                 check_remote_client_conda.format(tf_version=other_tf_version))
-        finally:
-            ray.util.disconnect()
-            ray._private.client_mode_hook._explicitly_disable_client_mode()
 
 
 @pytest.mark.skipif(
@@ -387,28 +384,23 @@ def test_conda_create_ray_client(call_ray_start):
             ]
         }
     }
-    try:
-        ray.client("localhost:24001").env(runtime_env).connect()
 
-        @ray.remote
-        def f():
-            import pip_install_test  # noqa
-            return True
+    @ray.remote
+    def f():
+        import pip_install_test  # noqa
+        return True
 
+    with ray.client("localhost:24001").env(runtime_env).connect():
         with pytest.raises(ModuleNotFoundError):
             # Ensure pip-install-test is not installed on the test machine
             import pip_install_test  # noqa
         assert ray.get(f.remote())
 
-        ray.util.disconnect()
-        ray.client("localhost:24001").connect()
+    with ray.client("localhost:24001").connect():
         with pytest.raises(ModuleNotFoundError):
             # Ensure pip-install-test is not installed in a client that doesn't
             # use the runtime_env
             ray.get(f.remote())
-    finally:
-        ray.util.disconnect()
-        ray._private.client_mode_hook._explicitly_disable_client_mode()
 
 
 @pytest.mark.skipif(