set all reduce fusion default group

mindspore/parallel/_auto_parallel_context.py

@@ -245,7 +245,7 @@ class _AutoParallelContext:
         self.check_context_handle()
         return self._context_handle.get_parameter_broadcast_is_set()
 
-    def set_all_reduce_fusion_split_indices(self, indices, group=""):
+    def set_all_reduce_fusion_split_indices(self, indices, group="hccl_world_groupsum1"):
         """
         Set allreduce fusion strategy by parameters indices.
 
@@ -279,7 +279,7 @@ class _AutoParallelContext:
             else:
                 _set_fusion_strategy_by_idx(indices, group)
 
-    def get_all_reduce_fusion_split_indices(self, group=""):
+    def get_all_reduce_fusion_split_indices(self, group="hccl_world_groupsum1"):
         """
         Get allreduce fusion split indices.
 
@@ -301,7 +301,7 @@ class _AutoParallelContext:
             raise TypeError('Group must be a python str')
         return self._context_handle.get_all_reduce_fusion_split_indices(group)
 
-    def set_all_reduce_fusion_split_sizes(self, sizes, group=""):
+    def set_all_reduce_fusion_split_sizes(self, sizes, group="hccl_world_groupsum1"):
         """
         Set allreduce fusion strategy by parameters data sizes.
 
@@ -335,7 +335,7 @@ class _AutoParallelContext:
             else:
                 _set_fusion_strategy_by_size(sizes, group)
 
-    def get_all_reduce_fusion_split_sizes(self, group=""):
+    def get_all_reduce_fusion_split_sizes(self, group="hccl_world_groupsum1"):
         """
         Get allreduce fusion split sizes.