[spark] Automatically shut down ray on spark cluster if user does not…

… execute commands on databricks notebook for a long time (ray-project#31962)

Databricks Runtime provides an API:
dbutils.entry_point.getIdleTimeMillisSinceLastNotebookExecution() that returns elapsed milliseconds since last databricks notebook code execution.
This PR code calls this interface to monitor notebook activity and shut down Ray cluster on timeout.

Signed-off-by: Weichen Xu <[email protected]>

python/ray/tests/BUILD

@@ -535,6 +535,7 @@ py_test_module_list(
     "spark/test_GPU.py",
     "spark/test_multicores_per_task.py",
     "spark/test_utils.py",
+    "spark/test_databricks_hook.py",
   ],
   size = "large",
   tags = ["exclusive", "spark_plugin_tests", "team:serverless"],

python/ray/tests/spark/test_basic.py

@@ -46,6 +46,7 @@ class RayOnSparkCPUClusterTestBase(ABC):
     @classmethod
     def teardown_class(cls):
         time.sleep(10)  # Wait all background spark job canceled.
+        os.environ.pop("SPARK_WORKER_CORES", None)
         cls.spark.stop()
 
     @staticmethod
@@ -70,6 +71,11 @@ def test_cpu_allocation(self):
                 self.num_cpus_per_spark_task * 2,
                 MAX_NUM_WORKER_NODES,
             ),
+            (
+                self.max_spark_tasks // 2,
+                self.num_cpus_per_spark_task * 2,
+                self.max_spark_tasks // 2 + 1,
+            ),  # Test case: requesting resources exceeding all cluster resources
         ]:
             with _setup_ray_cluster(
                 num_worker_nodes=num_worker_nodes_arg,
@@ -92,6 +98,12 @@ def test_public_api(self):
                 ray_temp_root_dir=ray_temp_root_dir,
                 head_node_options={"include_dashboard": True},
             )
+
+            assert (
+                os.environ["RAY_ADDRESS"]
+                == ray.util.spark.cluster_init._active_ray_cluster.address
+            )
+
             ray.init()
 
             @ray.remote
@@ -104,6 +116,8 @@ def f(x):
 
             shutdown_ray_cluster()
 
+            assert "RAY_ADDRESS" not in os.environ
+
             time.sleep(7)
             # assert temp dir is removed.
             assert len(os.listdir(ray_temp_root_dir)) == 1 and os.listdir(
@@ -121,7 +135,7 @@ def f(x):
             if ray.util.spark.cluster_init._active_ray_cluster is not None:
                 # if the test raised error and does not destroy cluster,
                 # destroy it here.
-                ray.util.spark._active_ray_cluster.shutdown()
+                ray.util.spark.cluster_init._active_ray_cluster.shutdown()
                 time.sleep(5)
             shutil.rmtree(ray_temp_root_dir, ignore_errors=True)
             shutil.rmtree(collect_log_to_path, ignore_errors=True)

python/ray/tests/spark/test_databricks_hook.py

@@ -0,0 +1,80 @@
+import sys
+
+import pytest
+import os
+import time
+import ray
+from pyspark.sql import SparkSession
+from ray.util.spark import setup_ray_cluster
+import ray.util.spark.databricks_hook
+
+
+pytestmark = pytest.mark.skipif(
+    not sys.platform.startswith("linux"),
+    reason="Ray on spark only supports running on Linux.",
+)
+
+
+class MockDbApiEntry:
+    def __init__(self):
+        self.created_time = time.time()
+        self.registered_job_groups = []
+
+    def getIdleTimeMillisSinceLastNotebookExecution(self):
+        return (time.time() - self.created_time) * 1000
+
+    def registerBackgroundSparkJobGroup(self, job_group_id):
+        self.registered_job_groups.append(job_group_id)
+
+
+class TestDatabricksHook:
+    @classmethod
+    def setup_class(cls):
+        os.environ["SPARK_WORKER_CORES"] = "2"
+        cls.spark = (
+            SparkSession.builder.master("local-cluster[1, 2, 1024]")
+            .config("spark.task.cpus", "1")
+            .config("spark.task.maxFailures", "1")
+            .config("spark.executorEnv.RAY_ON_SPARK_WORKER_CPU_CORES", "2")
+            .getOrCreate()
+        )
+
+    @classmethod
+    def teardown_class(cls):
+        time.sleep(10)  # Wait all background spark job canceled.
+        cls.spark.stop()
+        os.environ.pop("SPARK_WORKER_CORES")
+
+    def test_hook(self, monkeypatch):
+        monkeypatch.setattr(
+            "ray.util.spark.databricks_hook._DATABRICKS_DEFAULT_TMP_DIR", "/tmp"
+        )
+        monkeypatch.setenv("DATABRICKS_RUNTIME_VERSION", "12.2")
+        monkeypatch.setenv("DATABRICKS_RAY_ON_SPARK_AUTOSHUTDOWN_MINUTES", "0.5")
+        db_api_entry = MockDbApiEntry()
+        monkeypatch.setattr(
+            "ray.util.spark.databricks_hook._get_db_api_entry", lambda: db_api_entry
+        )
+        try:
+            setup_ray_cluster(
+                num_worker_nodes=2,
+                head_node_options={"include_dashboard": False},
+            )
+            cluster = ray.util.spark.cluster_init._active_ray_cluster
+            assert not cluster.is_shutdown
+            assert db_api_entry.registered_job_groups == [cluster.spark_job_group_id]
+            time.sleep(35)
+            assert cluster.is_shutdown
+            assert ray.util.spark.cluster_init._active_ray_cluster is None
+        finally:
+            if ray.util.spark.cluster_init._active_ray_cluster is not None:
+                # if the test raised error and does not destroy cluster,
+                # destroy it here.
+                ray.util.spark.cluster_init._active_ray_cluster.shutdown()
+
+
+if __name__ == "__main__":
+    if os.environ.get("PARALLEL_CI"):
+        sys.exit(pytest.main(["-n", "auto", "--boxed", "-vs", __file__]))
+    else:
+        sys.exit(pytest.main(["-sv", __file__]))

python/ray/util/spark/cluster_init.py

@@ -100,11 +100,6 @@ def _cancel_background_spark_job(self):
     def wait_until_ready(self):
         import ray
 
-        if self.background_job_exception is not None:
-            raise RuntimeError(
-                "Ray workers has exited."
-            ) from self.background_job_exception
-
         if self.is_shutdown:
             raise RuntimeError(
                 "The ray cluster has been shut down or it failed to start."
@@ -125,6 +120,16 @@ def wait_until_ready(self):
             last_progress_move_time = time.time()
             while True:
                 time.sleep(_RAY_CLUSTER_STARTUP_PROGRESS_CHECKING_INTERVAL)
+
+                # Inside the waiting ready loop,
+                # checking `self.background_job_exception`, if it is not None,
+                # it means the background spark job has failed,
+                # in this case, raise error directly.
+                if self.background_job_exception is not None:
+                    raise RuntimeError(
+                        "Ray workers have exited."
+                    ) from self.background_job_exception
+
                 cur_alive_worker_count = (
                     len([node for node in ray.nodes() if node["Alive"]]) - 1
                 )  # Minus 1 means excluding the head node.
@@ -144,12 +149,17 @@ def wait_until_ready(self):
                         time.time() - last_progress_move_time
                         > _RAY_CONNECT_CLUSTER_POLL_PROGRESS_TIMEOUT
                     ):
+                        if cur_alive_worker_count == 0:
+                            raise RuntimeError(
+                                "Current spark cluster has no resources to launch "
+                                "Ray worker nodes."
+                            )
                         _logger.warning(
                             "Timeout in waiting for all ray workers to start. "
                             "Started / Total requested: "
                             f"({cur_alive_worker_count} / {self.num_worker_nodes}). "
-                            "Please check ray logs to see why some ray workers "
-                            "failed to start."
+                            "Current spark cluster does not have sufficient resources "
+                            "to launch requested number of Ray worker nodes."
                         )
                         return
         finally:
@@ -678,7 +688,7 @@ def background_job_thread_fn():
         ).start()
 
         # Call hook immediately after spark job started.
-        start_hook.on_spark_background_job_created(spark_job_group_id)
+        start_hook.on_cluster_created(ray_cluster_handler)
 
         # wait background spark task starting.
         for _ in range(_BACKGROUND_JOB_STARTUP_WAIT):
@@ -699,6 +709,7 @@ def background_job_thread_fn():
 
 
 _active_ray_cluster = None
+_active_ray_cluster_rwlock = threading.RLock()
 
 
 def _create_resource_profile(num_cpus_per_node, num_gpus_per_node):
@@ -1007,23 +1018,24 @@ def setup_ray_cluster(
         else:
             _logger.warning("\n".join(insufficient_resources))
 
-    cluster = _setup_ray_cluster(
-        num_worker_nodes=num_worker_nodes,
-        num_cpus_per_node=num_cpus_per_node,
-        num_gpus_per_node=num_gpus_per_node,
-        using_stage_scheduling=using_stage_scheduling,
-        heap_memory_per_node=ray_worker_node_heap_mem_bytes,
-        object_store_memory_per_node=ray_worker_node_object_store_mem_bytes,
-        head_node_options=head_node_options,
-        worker_node_options=worker_node_options,
-        ray_temp_root_dir=ray_temp_root_dir,
-        collect_log_to_path=collect_log_to_path,
-    )
-    cluster.wait_until_ready()  # NB: this line might raise error.
+    with _active_ray_cluster_rwlock:
+        cluster = _setup_ray_cluster(
+            num_worker_nodes=num_worker_nodes,
+            num_cpus_per_node=num_cpus_per_node,
+            num_gpus_per_node=num_gpus_per_node,
+            using_stage_scheduling=using_stage_scheduling,
+            heap_memory_per_node=ray_worker_node_heap_mem_bytes,
+            object_store_memory_per_node=ray_worker_node_object_store_mem_bytes,
+            head_node_options=head_node_options,
+            worker_node_options=worker_node_options,
+            ray_temp_root_dir=ray_temp_root_dir,
+            collect_log_to_path=collect_log_to_path,
+        )
+        cluster.wait_until_ready()  # NB: this line might raise error.
 
-    # If connect cluster successfully, set global _active_ray_cluster to be the started
-    # cluster.
-    _active_ray_cluster = cluster
+        # If connect cluster successfully, set global _active_ray_cluster to be the
+        # started cluster.
+        _active_ray_cluster = cluster
     return cluster.address
 
 
@@ -1033,8 +1045,10 @@ def shutdown_ray_cluster() -> None:
     Shut down the active ray cluster.
     """
     global _active_ray_cluster
-    if _active_ray_cluster is None:
-        raise RuntimeError("No active ray cluster to shut down.")
 
-    _active_ray_cluster.shutdown()
-    _active_ray_cluster = None
+    with _active_ray_cluster_rwlock:
+        if _active_ray_cluster is None:
+            raise RuntimeError("No active ray cluster to shut down.")
+
+        _active_ray_cluster.shutdown()
+        _active_ray_cluster = None

python/ray/util/spark/databricks_hook.py

@@ -1,6 +1,10 @@
+import os
+
 from .start_hook_base import RayOnSparkStartHook
 from .utils import get_spark_session
 import logging
+import threading
+import time
 
 _logger = logging.getLogger(__name__)
 
@@ -54,21 +58,104 @@ def display_databricks_driver_proxy_url(spark_context, port, title):
     )
 
 
+DATABRICKS_AUTO_SHUTDOWN_POLL_INTERVAL_SECONDS = 3
+DATABRICKS_RAY_ON_SPARK_AUTOSHUTDOWN_MINUTES = (
+    "DATABRICKS_RAY_ON_SPARK_AUTOSHUTDOWN_MINUTES"
+)
+
+
+def _get_db_api_entry():
+    """
+    Get databricks API entry point.
+    """
+    return get_dbutils().entry_point
+
+
+_DATABRICKS_DEFAULT_TMP_DIR = "/local_disk0/tmp"
+
+
 class DefaultDatabricksRayOnSparkStartHook(RayOnSparkStartHook):
     def get_default_temp_dir(self):
-        return "/local_disk0/tmp"
+        return _DATABRICKS_DEFAULT_TMP_DIR
 
     def on_ray_dashboard_created(self, port):
         display_databricks_driver_proxy_url(
             get_spark_session().sparkContext, port, "Ray Cluster Dashboard"
         )
 
-    def on_spark_background_job_created(self, job_group_id):
+    def on_cluster_created(self, ray_cluster_handler):
+        db_api_entry = _get_db_api_entry()
         try:
-            get_dbutils().entry_point.registerBackgroundSparkJobGroup(job_group_id)
+            db_api_entry.registerBackgroundSparkJobGroup(
+                ray_cluster_handler.spark_job_group_id
+            )
         except Exception:
             _logger.warning(
-                "Register ray cluster spark job as background job failed. You need to "
-                "manually call `ray_cluster_on_spark.shutdown()` before detaching "
-                "your databricks python REPL."
+                "Registering Ray cluster spark job as background job failed. "
+                "You need to manually call `ray.util.spark.shutdown_ray_cluster()` "
+                "before detaching your databricks notebook."
+            )
+
+        auto_shutdown_minutes = float(
+            os.environ.get(DATABRICKS_RAY_ON_SPARK_AUTOSHUTDOWN_MINUTES, "30")
+        )
+        if auto_shutdown_minutes == 0:
+            _logger.info(
+                "The Ray cluster will keep running until you manually detach the "
+                "databricks notebook or call "
+                "`ray.util.spark.shutdown_ray_cluster()`."
+            )
+            return
+        if auto_shutdown_minutes < 0:
+            raise ValueError(
+                "You must set "
+                f"'{DATABRICKS_RAY_ON_SPARK_AUTOSHUTDOWN_MINUTES}' "
+                "to a value >= 0."
             )
+
+        try:
+            db_api_entry.getIdleTimeMillisSinceLastNotebookExecution()
+        except Exception:
+            _logger.warning(
+                "Databricks `getIdleTimeMillisSinceLastNotebookExecution` API "
+                "is unavailable, it is probably because that "
+                "your current Databricks Runtime version does not support API "
+                "`getIdleTimeMillisSinceLastNotebookExecution`, we cannot "
+                "automatically shut down Ray cluster when databricks notebook "
+                "is inactive, you need to manually detach databricks notebook "
+                "or call `ray.util.spark.shutdown_ray_cluster()` to shut down "
+                "Ray cluster on spark."
+            )
+            return
+
+        _logger.info(
+            "The Ray cluster will be shut down automatically if you don't run "
+            "commands on the databricks notebook for "
+            f"{auto_shutdown_minutes} minutes. You can change the "
+            "automatically shutdown minutes by setting "
+            f"'{DATABRICKS_RAY_ON_SPARK_AUTOSHUTDOWN_MINUTES}' environment "
+            "variable, setting it to 0 means that the Ray cluster keeps running "
+            "until you manually call `ray.util.spark.shutdown_ray_cluster()` or "
+            "detach databricks notebook."
+        )
+
+        def auto_shutdown_watcher():
+            auto_shutdown_millis = auto_shutdown_minutes * 60 * 1000
+            while True:
+                if ray_cluster_handler.is_shutdown:
+                    # The cluster is shut down. The watcher thread exits.
+                    return
+
+                idle_time = db_api_entry.getIdleTimeMillisSinceLastNotebookExecution()
+
+                if idle_time > auto_shutdown_millis:
+                    from ray.util.spark import cluster_init
+
+                    with cluster_init._active_ray_cluster_rwlock:
+                        if ray_cluster_handler is cluster_init._active_ray_cluster:
+                            cluster_init.shutdown_ray_cluster()
+                    return
+
+                time.sleep(DATABRICKS_AUTO_SHUTDOWN_POLL_INTERVAL_SECONDS)
+
+        threading.Thread(target=auto_shutdown_watcher, daemon=True).start()

python/ray/util/spark/start_hook_base.py

@@ -5,5 +5,5 @@ def get_default_temp_dir(self):
     def on_ray_dashboard_created(self, port):
         pass
 
-    def on_spark_background_job_created(self, job_group):
+    def on_cluster_created(self, ray_cluster_handler):
         pass

python/requirements_test.txt

@@ -55,7 +55,7 @@ pygame==2.1.2; python_version < '3.11'
 Pygments==2.13.0
 pymongo==4.3.2
 # TODO: Replace this with pyspark==3.4 once it is released.
-https://ml-team-public-read.s3.us-west-2.amazonaws.com/pyspark-3.4.0.dev0.tar.gz
+https://ml-team-public-read.s3.us-west-2.amazonaws.com/spark-pkgs/pyspark-3.4.0.dev0-0cb0fa313979e1b82ddd711a05d8c4e78cf6c9f5.tar.gz
 pytest==7.0.1
 pytest-asyncio==0.16.0
 pytest-rerunfailures==10.2