Set GRPC_ENABLE_FORK_SUPPORT to False (#2474)

Author: YuanTingHsieh

nvflare/fuel/f3/drivers/aio_grpc_driver.py

@@ -11,7 +11,9 @@
 # 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 asyncio
+import os
 import random
 import threading
 import time
@@ -278,6 +280,9 @@ class AioGrpcDriver(BaseDriver):
 
     def __init__(self):
         super().__init__()
+        # GRPC with fork issue: https://github.com/grpc/grpc/issues/28557
+        os.environ["GRPC_ENABLE_FORK_SUPPORT"] = "False"
+
         self.server = None
         self.options = GRPC_DEFAULT_OPTIONS
         self.logger = get_logger(self)

nvflare/fuel/f3/drivers/grpc_driver.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import os
 import threading
 from concurrent import futures
 from typing import Any, Dict, List, Union
@@ -202,6 +203,8 @@ def shutdown(self):
 class GrpcDriver(BaseDriver):
     def __init__(self):
         BaseDriver.__init__(self)
+        # GRPC with fork issue: https://github.com/grpc/grpc/issues/28557
+        os.environ["GRPC_ENABLE_FORK_SUPPORT"] = "False"
         self.server = None
         self.closing = False
         self.max_workers = 100