Make HTEX reject empty resource specification in MPI mode

parsl/executors/high_throughput/executor.py

@@ -645,7 +645,8 @@ def submit(self, func, resource_specification, *args, **kwargs):
         Returns:
               Future
         """
-        validate_resource_spec(resource_specification)
+
+        validate_resource_spec(resource_specification, is_mpi_enabled=self.enable_mpi_mode)
 
         if self.bad_state_is_set:
             raise self.executor_exception

parsl/executors/high_throughput/mpi_prefix_composer.py

@@ -18,13 +18,19 @@ def __str__(self):
         return f"Invalid resource specification options supplied: {self.invalid_keys}"
 
 
-def validate_resource_spec(resource_spec: Dict[str, str]):
+def validate_resource_spec(resource_spec: Dict[str, str], is_mpi_enabled: bool = False):
     """Basic validation of keys in the resource_spec
 
     Raises: InvalidResourceSpecification if the resource_spec
         is invalid (e.g, contains invalid keys)
     """
     user_keys = set(resource_spec.keys())
+
+    # empty resource_spec when mpi_mode is set causes parsl to hang
+    # ref issue #3427
+    if is_mpi_enabled and len(user_keys) == 0:
+        raise InvalidResourceSpecification({'mpi_mode requires parsl_resource_specification to be configured'})
+
     legal_keys = set(("ranks_per_node",
                       "num_nodes",
                       "num_ranks",

parsl/tests/test_mpi_apps/test_mpi_mode_enabled.py

@@ -6,6 +6,8 @@
 from parsl import python_app, bash_app
 from parsl.tests.configs.htex_local import fresh_config
 
+from parsl.executors.high_throughput.mpi_prefix_composer import InvalidResourceSpecification
+
 import os
 
 EXECUTOR_LABEL = "MPI_TEST"
@@ -169,3 +171,11 @@ def test_simulated_load(rounds: int = 100):
         total_ranks, nodes = future.result(timeout=10)
         assert len(nodes) == futures[future]["num_nodes"]
         assert total_ranks == futures[future]["num_nodes"] * futures[future]["ranks_per_node"]
+
+
+@pytest.mark.local
+def test_missing_resource_spec():
+
+    with pytest.raises(InvalidResourceSpecification):
+        future = mock_app(sleep_dur=0.4)
+        future.result(timeout=10)

parsl/tests/test_mpi_apps/test_resource_spec.py

@@ -122,18 +122,22 @@ def test_top_level():
 
 @pytest.mark.local
 @pytest.mark.parametrize(
-    "resource_spec, exception",
+    "resource_spec, is_mpi_enabled, exception",
     (
-        ({"num_nodes": 2, "ranks_per_node": 1}, None),
-        ({"launcher_options": "--debug_foo"}, None),
-        ({"num_nodes": 2, "BAD_OPT": 1}, InvalidResourceSpecification),
-        ({}, None),
+        ({"num_nodes": 2, "ranks_per_node": 1}, False, None),
+        ({"launcher_options": "--debug_foo"}, False, None),
+        ({"num_nodes": 2, "BAD_OPT": 1}, False, InvalidResourceSpecification),
+        ({}, False, None),
+        ({"num_nodes": 2, "ranks_per_node": 1}, True, None),
+        ({"launcher_options": "--debug_foo"}, True, None),
+        ({"num_nodes": 2, "BAD_OPT": 1}, True, InvalidResourceSpecification),
+        ({}, True, InvalidResourceSpecification),
     )
 )
-def test_resource_spec(resource_spec: Dict, exception):
+def test_resource_spec(resource_spec: Dict, is_mpi_enabled: bool, exception):
     if exception:
         with pytest.raises(exception):
-            validate_resource_spec(resource_spec)
+            validate_resource_spec(resource_spec, is_mpi_enabled=is_mpi_enabled)
     else:
-        result = validate_resource_spec(resource_spec)
+        result = validate_resource_spec(resource_spec, is_mpi_enabled=is_mpi_enabled)
         assert result is None