refactor(framework) Move gRPC stub wrapping with RetryInvoker to `f…

…lwr.common` (#4636)

src/py/flwr/common/retry_invoker.py

@@ -20,8 +20,16 @@
 import time
 from collections.abc import Generator, Iterable
 from dataclasses import dataclass
+from logging import INFO, WARN
 from typing import Any, Callable, Optional, Union, cast
 
+import grpc
+
+from flwr.common.constant import MAX_RETRY_DELAY
+from flwr.common.logger import log
+from flwr.proto.clientappio_pb2_grpc import ClientAppIoStub
+from flwr.proto.serverappio_pb2_grpc import ServerAppIoStub
+
 
 def exponential(
     base_delay: float = 1,
@@ -303,3 +311,62 @@ def giveup_check(_exception: Exception) -> bool:
                 # Trigger success event
                 try_call_event_handler(self.on_success)
                 return ret
+
+
+def _make_simple_grpc_retry_invoker() -> RetryInvoker:
+    """Create a simple gRPC retry invoker."""
+
+    def _on_sucess(retry_state: RetryState) -> None:
+        if retry_state.tries > 1:
+            log(
+                INFO,
+                "Connection successful after %.2f seconds and %s tries.",
+                retry_state.elapsed_time,
+                retry_state.tries,
+            )
+
+    def _on_backoff(retry_state: RetryState) -> None:
+        if retry_state.tries == 1:
+            log(WARN, "Connection attempt failed, retrying...")
+        else:
+            log(
+                WARN,
+                "Connection attempt failed, retrying in %.2f seconds",
+                retry_state.actual_wait,
+            )
+
+    def _on_giveup(retry_state: RetryState) -> None:
+        if retry_state.tries > 1:
+            log(
+                WARN,
+                "Giving up reconnection after %.2f seconds and %s tries.",
+                retry_state.elapsed_time,
+                retry_state.tries,
+            )
+
+    return RetryInvoker(
+        wait_gen_factory=lambda: exponential(max_delay=MAX_RETRY_DELAY),
+        recoverable_exceptions=grpc.RpcError,
+        max_tries=None,
+        max_time=None,
+        on_success=_on_sucess,
+        on_backoff=_on_backoff,
+        on_giveup=_on_giveup,
+        should_giveup=lambda e: e.code() != grpc.StatusCode.UNAVAILABLE,  # type: ignore
+    )
+
+
+def _wrap_stub(
+    stub: Union[ServerAppIoStub, ClientAppIoStub], retry_invoker: RetryInvoker
+) -> None:
+    """Wrap a gRPC stub with a retry invoker."""
+
+    def make_lambda(original_method: Any) -> Any:
+        return lambda *args, **kwargs: retry_invoker.invoke(
+            original_method, *args, **kwargs
+        )
+
+    for method_name in vars(stub):
+        method = getattr(stub, method_name)
+        if callable(method):
+            setattr(stub, method_name, make_lambda(method))

src/py/flwr/server/driver/grpc_driver.py

@@ -17,16 +17,16 @@
 import time
 import warnings
 from collections.abc import Iterable
-from logging import DEBUG, INFO, WARN, WARNING
-from typing import Any, Optional, cast
+from logging import DEBUG, WARNING
+from typing import Optional, cast
 
 import grpc
 
 from flwr.common import DEFAULT_TTL, Message, Metadata, RecordSet
-from flwr.common.constant import MAX_RETRY_DELAY, SERVERAPPIO_API_DEFAULT_CLIENT_ADDRESS
+from flwr.common.constant import SERVERAPPIO_API_DEFAULT_CLIENT_ADDRESS
 from flwr.common.grpc import create_channel
 from flwr.common.logger import log
-from flwr.common.retry_invoker import RetryInvoker, RetryState, exponential
+from flwr.common.retry_invoker import _make_simple_grpc_retry_invoker, _wrap_stub
 from flwr.common.serde import message_from_taskres, message_to_taskins, run_from_proto
 from flwr.common.typing import Run
 from flwr.proto.node_pb2 import Node  # pylint: disable=E0611
@@ -262,60 +262,3 @@ def close(self) -> None:
             return
         # Disconnect
         self._disconnect()
-
-
-def _make_simple_grpc_retry_invoker() -> RetryInvoker:
-    """Create a simple gRPC retry invoker."""
-
-    def _on_sucess(retry_state: RetryState) -> None:
-        if retry_state.tries > 1:
-            log(
-                INFO,
-                "Connection successful after %.2f seconds and %s tries.",
-                retry_state.elapsed_time,
-                retry_state.tries,
-            )
-
-    def _on_backoff(retry_state: RetryState) -> None:
-        if retry_state.tries == 1:
-            log(WARN, "Connection attempt failed, retrying...")
-        else:
-            log(
-                WARN,
-                "Connection attempt failed, retrying in %.2f seconds",
-                retry_state.actual_wait,
-            )
-
-    def _on_giveup(retry_state: RetryState) -> None:
-        if retry_state.tries > 1:
-            log(
-                WARN,
-                "Giving up reconnection after %.2f seconds and %s tries.",
-                retry_state.elapsed_time,
-                retry_state.tries,
-            )
-
-    return RetryInvoker(
-        wait_gen_factory=lambda: exponential(max_delay=MAX_RETRY_DELAY),
-        recoverable_exceptions=grpc.RpcError,
-        max_tries=None,
-        max_time=None,
-        on_success=_on_sucess,
-        on_backoff=_on_backoff,
-        on_giveup=_on_giveup,
-        should_giveup=lambda e: e.code() != grpc.StatusCode.UNAVAILABLE,  # type: ignore
-    )
-
-
-def _wrap_stub(stub: ServerAppIoStub, retry_invoker: RetryInvoker) -> None:
-    """Wrap the gRPC stub with a retry invoker."""
-
-    def make_lambda(original_method: Any) -> Any:
-        return lambda *args, **kwargs: retry_invoker.invoke(
-            original_method, *args, **kwargs
-        )
-
-    for method_name in vars(stub):
-        method = getattr(stub, method_name)
-        if callable(method):
-            setattr(stub, method_name, make_lambda(method))