Moving tests from test/ to python/ray/tests/ (#3950)

python/ray/tests/test_node_manager.py

@@ -0,0 +1,63 @@
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import pytest
+
+import ray
+from ray.tests.cluster_utils import Cluster
+from ray.tests.utils import run_string_as_driver
+
+
+@pytest.fixture()
+def ray_start_empty_cluster():
+    cluster = Cluster()
+    yield cluster
+
+    # The code after the yield will run as teardown code.
+    ray.shutdown()
+    cluster.shutdown()
+
+
+# This tests the queue transitions for infeasible tasks. This has been an issue
+# in the past, e.g., https://github.com/ray-project/ray/issues/3275.
+def test_infeasible_tasks(ray_start_empty_cluster):
+    cluster = ray_start_empty_cluster
+
+    @ray.remote
+    def f():
+        return
+
+    cluster.add_node(resources={str(0): 100})
+    ray.init(redis_address=cluster.redis_address)
+
+    # Submit an infeasible task.
+    x_id = f._submit(args=[], kwargs={}, resources={str(1): 1})
+
+    # Add a node that makes the task feasible and make sure we can get the
+    # result.
+    cluster.add_node(resources={str(1): 100})
+    ray.get(x_id)
+
+    # Start a driver that submits an infeasible task and then let it exit.
+    driver_script = """
+import ray
+
+ray.init(redis_address="{}")
+
+@ray.remote(resources={})
+def f():
+{}pass  # This is a weird hack to insert some blank space.
+
+f.remote()
+""".format(cluster.redis_address, "{str(2): 1}", "    ")
+
+    run_string_as_driver(driver_script)
+
+    # Now add a new node that makes the task feasible.
+    cluster.add_node(resources={str(2): 100})
+
+    # Make sure we can still run tasks on all nodes.
+    ray.get([
+        f._submit(args=[], kwargs={}, resources={str(i): 1}) for i in range(3)
+    ])