Remove AcceleratorConnector.parallel_devices (#12075)

CHANGELOG.md

@@ -795,6 +795,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Removed `AcceleratorConnector.devices` property ([#12435](https://github.com/PyTorchLightning/pytorch-lightning/pull/12435))
 
 
+- Removed `AcceleratorConnector.parallel_devices` property ([#12075](https://github.com/PyTorchLightning/pytorch-lightning/pull/12075))
+
+
 ### Fixed
 
 - Fixed an issue where `ModelCheckpoint` could delete older checkpoints when `dirpath` has changed during resumed training ([#12045](https://github.com/PyTorchLightning/pytorch-lightning/pull/12045))

pytorch_lightning/trainer/connectors/accelerator_connector.py

@@ -775,10 +775,6 @@ class AcceleratorConnector:
     of accessing this information through the strategy/accelerator directly."""
     # TODO: deprecate all properties below
 
-    @property
-    def parallel_devices(self) -> List[Union[torch.device, int]]:
-        return self._parallel_devices
-
     @property
     def tpu_cores(self) -> Optional[Union[List[int], int]]:
         if isinstance(self.accelerator, TPUAccelerator):

tests/accelerators/test_accelerator_registry.py

@@ -56,7 +56,7 @@ def test_accelerator_registry_with_new_accelerator():
 
     trainer = Trainer(accelerator=accelerator_name, devices="auto")
     assert isinstance(trainer.accelerator, CustomAccelerator)
-    assert trainer._accelerator_connector.parallel_devices == ["foo"] * 3
+    assert trainer.strategy.parallel_devices == ["foo"] * 3
 
     AcceleratorRegistry.remove(accelerator_name)
     assert accelerator_name not in AcceleratorRegistry

tests/accelerators/test_common.py

@@ -51,9 +51,9 @@ def test_pluggable_accelerator():
     trainer = Trainer(accelerator=TestAccelerator(), devices=2, strategy="ddp")
     assert isinstance(trainer.accelerator, TestAccelerator)
     assert isinstance(trainer.strategy, DDPStrategy)
-    assert trainer._accelerator_connector.parallel_devices == ["foo"] * 2
+    assert trainer.strategy.parallel_devices == ["foo"] * 2
 
     trainer = Trainer(strategy=DDPStrategy(TestAccelerator()), devices="auto")
     assert isinstance(trainer.accelerator, TestAccelerator)
     assert isinstance(trainer.strategy, DDPStrategy)
-    assert trainer._accelerator_connector.parallel_devices == ["foo"] * 3
+    assert trainer.strategy.parallel_devices == ["foo"] * 3