Remove deprecated `task_idx` (#10441)

CHANGELOG.md

@@ -90,6 +90,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Removed deprecated `LightningModule.log(tbptt_reduce_fx, tbptt_reduce_token, sync_dist_op)` ([#10423](https://github.com/PyTorchLightning/pytorch-lightning/pull/10423))
 
 
+- Removed deprecated `Plugin.task_idx` ([#10441](https://github.com/PyTorchLightning/pytorch-lightning/pull/10441))
+
+
 - Removed PyTorch 1.6 support ([#10367](https://github.com/PyTorchLightning/pytorch-lightning/pull/10367))
 
 

pytorch_lightning/plugins/training_type/ddp.py

@@ -47,7 +47,6 @@ from pytorch_lightning.utilities import (
     _TORCH_GREATER_EQUAL_1_8,
     _TORCH_GREATER_EQUAL_1_9,
     _TORCH_GREATER_EQUAL_1_10,
-    rank_zero_deprecation,
     rank_zero_warn,
 )
 from pytorch_lightning.utilities.distributed import distributed_available
@@ -105,7 +104,6 @@ class DDPPlugin(ParallelPlugin):
         self.sync_batchnorm = False
         self.num_processes = len(self.parallel_devices) if self.parallel_devices is not None else 0
         self._ddp_kwargs = kwargs
-        self._task_idx = None
         self._ddp_comm_state = ddp_comm_state
         self._ddp_comm_hook = ddp_comm_hook
         self._ddp_comm_wrapper = ddp_comm_wrapper
@@ -133,18 +131,6 @@ class DDPPlugin(ParallelPlugin):
         self._num_nodes = num_nodes
         self.set_world_ranks()
 
-    @property
-    def task_idx(self) -> Optional[int]:
-        rank_zero_deprecation(
-            f"`{self.__class__.__name__}.task_idx` is deprecated in v1.4 and will be removed in v1.6. Use "
-            f"`{self.__class__.__name__}.local_rank` instead."
-        )
-        return self._task_idx
-
-    @task_idx.setter
-    def task_idx(self, task_idx: int) -> None:
-        self._task_idx = task_idx
-
     @property
     def distributed_sampler_kwargs(self):
         distributed_sampler_kwargs = dict(num_replicas=(self.num_nodes * self.num_processes), rank=self.global_rank)
@@ -159,9 +145,6 @@ class DDPPlugin(ParallelPlugin):
         if not self.cluster_environment.creates_processes_externally:
             self._call_children_scripts()
 
-        # set the task idx
-        self.task_idx = self.cluster_environment.local_rank()
-
         self.setup_distributed()
 
     def _setup_model(self, model: Module) -> DistributedDataParallel:

pytorch_lightning/plugins/training_type/ddp2.py

@@ -32,11 +32,6 @@ class DDP2Plugin(DDPPlugin):
     def world_size(self) -> int:
         return self.num_nodes
 
-    def setup(self) -> None:
-        # set the task idx
-        self.task_idx = self.cluster_environment.local_rank()
-        # the difference to DDP is that we don't call children processes here
-
     def reduce(self, collection: _METRIC_COLLECTION, *args, **kwargs) -> _METRIC_COLLECTION:
         """Reduces a collection of tensors from all processes. It can be applied to just a single tensor. In DDP2,
         the reduction here is only across local devices within the node.

tests/deprecated_api/test_remove_1-6.py

@@ -17,7 +17,6 @@ from unittest.mock import call, Mock
 import pytest
 
 from pytorch_lightning import Trainer
-from pytorch_lightning.plugins.training_type import DDPPlugin
 from pytorch_lightning.utilities.distributed import rank_zero_deprecation, rank_zero_warn
 from pytorch_lightning.utilities.model_helpers import is_overridden
 from pytorch_lightning.utilities.model_summary import ModelSummary
@@ -86,12 +85,6 @@ def test_v1_6_0_rank_zero_warnings_moved():
         rank_zero_deprecation("test")
 
 
-def test_v1_6_0_ddp_plugin_task_idx():
-    plugin = DDPPlugin()
-    with pytest.deprecated_call(match="Use `DDPPlugin.local_rank` instead"):
-        _ = plugin.task_idx
-
-
 def test_v1_6_0_deprecated_model_summary_mode(tmpdir):
     model = BoringModel()
     with pytest.deprecated_call(match="Argument `mode` in `ModelSummary` is deprecated in v1.4"):