Add communication strategy group

python/paddle/distributed/fleet/base/orthogonal_strategy.py

@@ -0,0 +1,181 @@
+# Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import itertools
+import collections
+import functools
+import paddle.distributed as dist
+from paddle.distributed.fleet.base.strategy_group import StrategyGroupBase
+
+
+class OrthogonalStrategy():
+    """
+    A hybrid of multiple distributed strategies. Strategies need to be orthogonal, means the ranks are organized like
+    a square if there are two strategies, a cube if there aree three strategies, etc.
+
+    Args:
+        list_of_strategy(list): Stategy in the list should be represented as tuple, format as (strategy_name, degree, strategy_class).
+        fused_strategy_dict(dict, optional): Exist strategies can be fused to new strategy. Use the name of new strategy as key, a list of
+            strategy names you want to fuse as value.
+
+    Returns:
+        The instance of strategy.
+
+    Examples:
+        .. code-block:: python
+
+        # required: distributed
+        import paddle
+        import paddle.distributed as dist
+        from paddle.distributed.fleet.base.strategy_group import DPGroup, MPGroup, PPGroup
+        from paddle.distributed.fleet.base.orthogonal_strategy import OrthogonalStrategy
+
+        dist.init_parallel_env()
+        strategy = OrthogonalStrategy([("dp", 2, DPGroup), ("mp", 2, MPGroup), ("pp", 2, PPGroup)], fused_strategy_dict={"check": ["mp", "pp"]})
+
+    """
+
+    def __init__(self, list_of_strategy, fused_strategy_dict={}):
+        self._list_of_strategy = list_of_strategy
+        self._fused_strategy_dict = fused_strategy_dict
+        self._rank = dist.get_rank()
+        self._rank_list_dict = {}
+        self._name_to_group_dict = {}
+        self._name_to_degree_dict = {}
+        self._list_of_strategy_name = [
+            strategy[0] for strategy in list_of_strategy
+        ]
+        self._list_of_degree = [strategy[1] for strategy in list_of_strategy]
+        self._coordinate = collections.namedtuple('Coordinate',
+                                                  self._list_of_strategy_name)
+        self._check_valid_strategy()
+
+        ranges = [range(degree) for degree in self._list_of_degree]
+        list_of_coord = [
+            self._coordinate(*coord) for coord in itertools.product(*ranges)
+        ]
+        self._coord_to_rank_dict = dict(
+            zip(list_of_coord, range(len(list_of_coord))))
+
+        for idx, strategy in enumerate(list_of_strategy):
+            strategy_name = strategy[0]
+            self._name_to_degree_dict[strategy_name] = strategy[1]
+            self._rank_list_dict[strategy_name] = self._calc_rank_list(idx)
+            self._name_to_group_dict[strategy_name] = strategy[2](
+                self._rank_list_dict[strategy_name])
+
+        self._name_to_fused_group_dict = {}
+        self._create_fused_group()
+
+    def strategy_group(self, name):
+        """
+        Get strategy group with specific name.
+
+        Args:
+            name: The name of strategy group
+
+        Returns:
+            An instance of specific strategy group.
+        """
+        assert name in self._list_of_strategy_name, "Strategy group {} is not created.".format(
+            name)
+        return self._name_to_group_dict[name]
+
+    def fused_strategy_group(self, name):
+        """
+        Get fused strategy group with specific name.
+
+        Args:
+            name: The name of fused strategy group
+
+        Returns:
+            (StrategyGroupBase): An instance of strategy group.
+        """
+        assert name in self._name_to_fused_group_dict, "Fused strategy group {} is not created.".format(
+            name)
+        return self._name_to_fused_group_dict[name]
+
+    def rank_in_strategy(self, name):
+        """
+        Get local rank in strategy group with specific name.
+
+        Args:
+            name: The name of strategy group
+
+        Returns:
+            (Integer): Local rank in specific strategy.
+        """
+        assert name in self._list_of_strategy_name, "Strategy group {} is not created.".format(
+            name)
+        return self._name_to_group_dict[name].group.rank
+
+    def _check_valid_strategy(self):
+        assert len(self._list_of_strategy_name) == len(
+            set(self._list_of_strategy_name)
+        ), "Defined duplicated strategies: {}".format(list_of_strategy)
+        num_of_ranks = functools.reduce(lambda x, y: x * y,
+                                        self._list_of_degree)
+        assert num_of_ranks == dist.get_world_size(
+        ), "There are total {} ranks, but need {} ranks in this strategy.".format(
+            dist.get_world_size(), num_of_ranks)
+        for fused_strategy in self._fused_strategy_dict.values():
+            for strategy in fused_strategy:
+                assert strategy in self._list_of_strategy_name, "Can not fuse strategy {} without defined previous.".format(
+                    strategy)
+
+    def _create_fused_group(self):
+        for name in self._fused_strategy_dict:
+            fused_strategy = self._fused_strategy_dict[name]
+            non_fused_strategy = list(
+                set(self._list_of_strategy_name).difference(fused_strategy))
+            non_fused_ranges = []
+            for strategy in non_fused_strategy:
+                non_fused_ranges.append(
+                    range(self._name_to_degree_dict[strategy]))
+            fused_ranges = []
+            for strategy in fused_strategy:
+                fused_ranges.append(range(self._name_to_degree_dict[strategy]))
+
+            rank_list = []
+            for non_fused_ranks in itertools.product(*non_fused_ranges):
+                coord_dict = {}
+                ranks = []
+                for i, non_fused_rank in enumerate(non_fused_ranks):
+                    coord_dict[non_fused_strategy[i]] = non_fused_rank
+                for fused_ranks in itertools.product(*fused_ranges):
+                    for i, fused_rank in enumerate(fused_ranks):
+                        coord_dict[fused_strategy[i]] = fused_rank
+                    ranks.append(self._coord_to_rank_dict[self._coordinate(
+                        **coord_dict)])
+                rank_list.append(ranks)
+            self._name_to_fused_group_dict[name] = StrategyGroupBase(rank_list)
+
+    def _calc_rank_list(self, strategy_axis):
+        ranges = []
+        for idx, degree in enumerate(self._list_of_degree):
+            if idx == strategy_axis:
+                continue
+            ranges.append(range(degree))
+
+        rank_list = []
+        for coord in itertools.product(*ranges):
+            ranks = []
+            for val in range(self._list_of_degree[strategy_axis]):
+                coord_list = list(coord)
+                coord_list.insert(strategy_axis, val)
+                ranks.append(
+                    self._coord_to_rank_dict[self._coordinate(*coord_list)])
+            rank_list.append(ranks)
+
+        return rank_list