Fix DDPStrategy import in app framework after #14952 (#16029)

(cherry picked from commit fcd3195)
Lightning-AI · Dec 14, 2022 · 89e14c9 · 89e14c9
1 parent dc96640
commit 89e14c9
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Showing 2 changed files with 5 additions and 5 deletions.
diff --git a/src/lightning_app/components/multi_node/lite.py b/src/lightning_app/components/multi_node/lite.py
@@ -40,8 +40,8 @@ def run(
             try:
                 pkg = importlib.import_module(pkg_name)
                 lites.append(pkg.LightningLite)
-                strategies.append(pkg.strategies.DDPSpawnShardedStrategy)
-                strategies.append(pkg.strategies.DDPSpawnStrategy)
+                strategies.append(pkg.strategies.DDPShardedStrategy)
+                strategies.append(pkg.strategies.DDPStrategy)
                 mps_accelerators.append(pkg.accelerators.MPSAccelerator)
             except (ImportError, ModuleNotFoundError):
                 continue
@@ -81,7 +81,7 @@ def pre_fn(lite, *args, **kwargs):
                         strategy = "ddp"
                     elif strategy == "ddp_sharded_spawn":
                         strategy = "ddp_sharded"
-                elif isinstance(strategy, tuple(strategies)):
+                elif isinstance(strategy, tuple(strategies)) and strategy._start_method in ("spawn", "fork"):
                     raise ValueError("DDP Spawned strategies aren't supported yet.")
 
             kwargs["strategy"] = strategy

diff --git a/tests/tests_app/components/multi_node/test_lite.py b/tests/tests_app/components/multi_node/test_lite.py
@@ -97,7 +97,7 @@ def test_trainer_run_executor_arguments_choices(args_given: dict, args_expected:
 @pytest.mark.skipif(not module_available("lightning"), reason="Lightning not available")
 def test_lite_run_executor_invalid_strategy_instances():
     with pytest.raises(ValueError, match="DDP Spawned strategies aren't supported yet."):
-        _, _ = _get_args_after_tracer_injection(strategy=ll.strategies.DDPSpawnStrategy())
+        _, _ = _get_args_after_tracer_injection(strategy=ll.strategies.DDPStrategy(start_method="spawn"))
 
     with pytest.raises(ValueError, match="DDP Spawned strategies aren't supported yet."):
-        _, _ = _get_args_after_tracer_injection(strategy=ll.strategies.DDPSpawnShardedStrategy())
+        _, _ = _get_args_after_tracer_injection(strategy=ll.strategies.DDPShardedStrategy(start_method="spawn"))