checkpointing: move to subfolder

torchft/checkpointing/__init__.py

@@ -0,0 +1,20 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+"""
+Checkpointing
+==============
+
+This module implements methods for checkpointing and resuming training from a checkpoint.
+"""
+
+from torchft.checkpointing.http_transport import HTTPTransport
+from torchft.checkpointing.transport import CheckpointTransport
+
+__all__ = [
+    "HTTPTransport",
+    "CheckpointTransport",
+]

torchft/checkpointing.py → torchft/checkpointing/http_transport.py

@@ -4,13 +4,6 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
-"""
-Checkpointing
-==============
-
-This module implements methods for checkpointing and resuming training from a checkpoint.
-"""
-
 import io
 import logging
 import socket
@@ -24,70 +17,14 @@
 
 import torch
 
+from torchft.checkpointing.transport import CheckpointTransport
 from torchft.http import _IPv6HTTPServer
 
 logger: logging.Logger = logging.getLogger(__name__)
 
 T = TypeVar("T")
 
 
-class CheckpointTransport(Generic[T], ABC):
-    @abstractmethod
-    def metadata(self) -> str:
-        """
-        Returns a string that will be used by the remote CheckpointTransport to fetch the checkpoint.
-        """
-        ...
-
-    @abstractmethod
-    def send_checkpoint(
-        self, dst_ranks: List[int], step: int, state_dict: T, timeout: timedelta
-    ) -> None:
-        """
-        Sends the checkpoint, only called when there is a rank that is behind.
-
-        This may be async.
-
-        Args:
-            dst_ranks: the ranks to send to
-            step: the step number to send
-            state_dict: the state dict to send
-            timeout: the timeout to wait for the checkpoint to be sent
-        """
-        ...
-
-    def disallow_checkpoint(self) -> None:
-        """
-        Called after send_checkpoint to wait for the checkpoint to be sent.
-
-        Once this returns, the state_dict may be mutated so no further data should be sent.
-        """
-        ...
-
-    @abstractmethod
-    def recv_checkpoint(
-        self, src_rank: int, metadata: str, step: int, timeout: timedelta
-    ) -> T:
-        """
-        Receives the checkpoint from the given rank.
-
-        Args:
-            src_rank: the rank to receive the checkpoint from
-            metadata: the metadata returned by the remote CheckpointTransport
-            step: the step number to receive
-            timeout: the timeout to wait for the checkpoint
-        """
-        ...
-
-    def shutdown(self, wait: bool = True) -> None:
-        """
-        Called to shutdown the checkpoint transport.
-
-        Args:
-            wait: whether to wait for the transport to shutdown
-        """
-
-
 @contextmanager
 def _timed_acquire(
     lock: threading.Lock, timeout: timedelta
@@ -107,7 +44,7 @@ def _timed_acquire(
         lock.release()
 
 
-class CheckpointServer(CheckpointTransport[T]):
+class HTTPTransport(CheckpointTransport[T]):
     """
     This is an HTTP server that can be used to transfer checkpoints
     between workers.

torchft/checkpointing_test.py → torchft/checkpointing/http_transport_test.py

@@ -10,15 +10,15 @@
 from unittest import TestCase
 from unittest.mock import MagicMock
 
-from torchft.checkpointing import CheckpointServer, _timed_acquire
+from torchft.checkpointing.http_transport import HTTPTransport, _timed_acquire
 
 
 class TestCheckpointing(TestCase):
     def test_checkpoint_server(self) -> None:
         expected = {"state": "dict"}
         state_dict_fn = MagicMock()
         state_dict_fn.return_value = expected
-        server = CheckpointServer(
+        server = HTTPTransport(
             timeout=timedelta(seconds=10),
         )
 
@@ -58,7 +58,7 @@ def test_checkpoint_server(self) -> None:
         server.shutdown()
 
     def test_checkpoint_server_locking(self) -> None:
-        server = CheckpointServer(
+        server = HTTPTransport(
             timeout=timedelta(seconds=10),
         )
 

torchft/checkpointing/transport.py

@@ -0,0 +1,68 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+from abc import ABC, abstractmethod
+from datetime import timedelta
+from typing import Generic, List, TypeVar
+
+T = TypeVar("T")
+
+
+class CheckpointTransport(Generic[T], ABC):
+    @abstractmethod
+    def metadata(self) -> str:
+        """
+        Returns a string that will be used by the remote CheckpointTransport to fetch the checkpoint.
+        """
+        ...
+
+    @abstractmethod
+    def send_checkpoint(
+        self, dst_ranks: List[int], step: int, state_dict: T, timeout: timedelta
+    ) -> None:
+        """
+        Sends the checkpoint, only called when there is a rank that is behind.
+
+        This may be async.
+
+        Args:
+            dst_ranks: the ranks to send to
+            step: the step number to send
+            state_dict: the state dict to send
+            timeout: the timeout to wait for the checkpoint to be sent
+        """
+        ...
+
+    def disallow_checkpoint(self) -> None:
+        """
+        Called after send_checkpoint to wait for the checkpoint to be sent.
+
+        Once this returns, the state_dict may be mutated so no further data should be sent.
+        """
+        ...
+
+    @abstractmethod
+    def recv_checkpoint(
+        self, src_rank: int, metadata: str, step: int, timeout: timedelta
+    ) -> T:
+        """
+        Receives the checkpoint from the given rank.
+
+        Args:
+            src_rank: the rank to receive the checkpoint from
+            metadata: the metadata returned by the remote CheckpointTransport
+            step: the step number to receive
+            timeout: the timeout to wait for the checkpoint
+        """
+        ...
+
+    def shutdown(self, wait: bool = True) -> None:
+        """
+        Called to shutdown the checkpoint transport.
+
+        Args:
+            wait: whether to wait for the transport to shutdown
+        """

torchft/fsdp_test.py

@@ -66,8 +66,8 @@ def _test_fsdp(world_size: int, rank: int) -> None:
     # pyre-ignore[56]: Pyre was not able to infer the type of argument
     @unittest.skipIf(torch.cuda.device_count() < 4, "Not enough GPUs")
     def test_fsdp(self) -> None:
-        multiprocessing.set_start_method("spawn")
-        with ProcessPoolExecutor(max_workers=4) as executor:
+        context = multiprocessing.get_context("spawn")
+        with ProcessPoolExecutor(max_workers=4, mp_context=context) as executor:
             futures = []
             for i in range(4):
                 future = executor.submit(self._test_fsdp, 4, i)

torchft/manager.py

@@ -38,7 +38,7 @@
 import torch
 from torch.distributed import ReduceOp, TCPStore
 
-from torchft.checkpointing import CheckpointServer, CheckpointTransport
+from torchft.checkpointing import CheckpointTransport, HTTPTransport
 from torchft.futures import future_timeout
 from torchft.torchft import Manager as _Manager, ManagerClient
 
@@ -141,7 +141,7 @@ def __init__(
             replica_id: if rank==0, the replica_id for this group
             hostname: if rank==0, the hostname to advertise to the lighthouse server
             checkpoint_transport: the checkpoint transport to use for
-                transfering checkpoints to recovering replicas
+                transfering checkpoints to recovering replicas, defaults to HTTPTransport
         """
         self._load_state_dict = load_state_dict
         self._user_state_dict = state_dict
@@ -160,7 +160,7 @@ def __init__(
         self._min_replica_size = min_replica_size
 
         if checkpoint_transport is None:
-            checkpoint_transport = CheckpointServer[Dict[str, T]](
+            checkpoint_transport = HTTPTransport[Dict[str, T]](
                 timeout=timeout,
             )