fix: add a health manager for restarting unhealthy mqtt connections

roborock/devices/mqtt_channel.py

@@ -82,6 +82,10 @@ async def publish(self, message: RoborockMessage) -> None:
             _LOGGER.exception("Error publishing MQTT message: %s", e)
             raise RoborockException(f"Failed to publish MQTT message: {e}") from e
 
+    async def restart(self) -> None:
+        """Restart the underlying MQTT session."""
+        await self._mqtt_session.restart()
+
 
 def create_mqtt_channel(
     user_data: UserData, mqtt_params: MqttParams, mqtt_session: MqttSession, device: HomeDataDevice

roborock/devices/v1_rpc_channel.py

@@ -13,6 +13,7 @@
 
 from roborock.data import RoborockBase
 from roborock.exceptions import RoborockException
+from roborock.mqtt.health_manager import HealthManager
 from roborock.protocols.v1_protocol import (
     CommandType,
     MapResponse,
@@ -125,12 +126,14 @@ def __init__(
         channel: MqttChannel | LocalChannel,
         payload_encoder: Callable[[RequestMessage], RoborockMessage],
         decoder: Callable[[RoborockMessage], ResponseMessage] | Callable[[RoborockMessage], MapResponse | None],
+        health_manager: HealthManager | None = None,
     ) -> None:
         """Initialize the channel with a raw channel and an encoder function."""
         self._name = name
         self._channel = channel
         self._payload_encoder = payload_encoder
         self._decoder = decoder
+        self._health_manager = health_manager
 
     async def _send_raw_command(
         self,
@@ -165,13 +168,19 @@ def find_response(response_message: RoborockMessage) -> None:
         unsub = await self._channel.subscribe(find_response)
         try:
             await self._channel.publish(message)
-            return await asyncio.wait_for(future, timeout=_TIMEOUT)
+            result = await asyncio.wait_for(future, timeout=_TIMEOUT)
         except TimeoutError as ex:
+            if self._health_manager:
+                await self._health_manager.on_timeout()
             future.cancel()
             raise RoborockException(f"Command timed out after {_TIMEOUT}s") from ex
         finally:
             unsub()
 
+        if self._health_manager:
+            await self._health_manager.on_success()
+        return result
+
 
 def create_mqtt_rpc_channel(mqtt_channel: MqttChannel, security_data: SecurityData) -> V1RpcChannel:
     """Create a V1 RPC channel using an MQTT channel."""
@@ -180,6 +189,7 @@ def create_mqtt_rpc_channel(mqtt_channel: MqttChannel, security_data: SecurityDa
         mqtt_channel,
         lambda x: x.encode_message(RoborockMessageProtocol.RPC_REQUEST, security_data=security_data),
         decode_rpc_response,
+        health_manager=HealthManager(mqtt_channel.restart),
     )
 
 

roborock/mqtt/health_manager.py

@@ -0,0 +1,51 @@
+"""A health manager for monitoring MQTT connections to Roborock devices.
+
+We observe a problem where sometimes the MQTT connection appears to be alive but
+no messages are being received. To mitigate this, we track consecutive timeouts
+and restart the connection if too many timeouts occur in succession.
+"""
+
+import datetime
+from collections.abc import Awaitable, Callable
+
+# Number of consecutive timeouts before considering the connection unhealthy.
+TIMEOUT_THRESHOLD = 3
+
+# We won't restart the session more often than this interval.
+RESTART_COOLDOWN = datetime.timedelta(minutes=30)
+
+
+class HealthManager:
+    """Manager for monitoring the health of MQTT connections.
+
+    This tracks communication timeouts and can trigger restarts of the MQTT
+    session if too many timeouts occur in succession.
+    """
+
+    def __init__(self, restart: Callable[[], Awaitable[None]]) -> None:
+        """Initialize the health manager.
+
+        Args:
+            restart: A callable to restart the MQTT session.
+        """
+        self._consecutive_timeouts = 0
+        self._restart = restart
+        self._last_restart: datetime.datetime | None = None
+
+    async def on_success(self) -> None:
+        """Record a successful communication event."""
+        self._consecutive_timeouts = 0
+
+    async def on_timeout(self) -> None:
+        """Record a timeout event.
+
+        This may trigger a restart of the MQTT session if too many timeouts
+        have occurred in succession.
+        """
+        self._consecutive_timeouts += 1
+        if self._consecutive_timeouts >= TIMEOUT_THRESHOLD:
+            now = datetime.datetime.now(datetime.UTC)
+            if self._last_restart is None or now - self._last_restart >= RESTART_COOLDOWN:
+                await self._restart()
+                self._last_restart = now
+                self._consecutive_timeouts = 0

roborock/mqtt/roborock_session.py

@@ -49,13 +49,14 @@ class RoborockMqttSession(MqttSession):
 
     def __init__(self, params: MqttParams):
         self._params = params
-        self._background_task: asyncio.Task[None] | None = None
+        self._reconnect_task: asyncio.Task[None] | None = None
         self._healthy = False
         self._stop = False
         self._backoff = MIN_BACKOFF_INTERVAL
         self._client: aiomqtt.Client | None = None
         self._client_lock = asyncio.Lock()
         self._listeners: CallbackMap[str, bytes] = CallbackMap(_LOGGER)
+        self._connection_task: asyncio.Task[None] | None = None
 
     @property
     def connected(self) -> bool:
@@ -72,7 +73,7 @@ async def start(self) -> None:
         """
         start_future: asyncio.Future[None] = asyncio.Future()
         loop = asyncio.get_event_loop()
-        self._background_task = loop.create_task(self._run_task(start_future))
+        self._reconnect_task = loop.create_task(self._run_reconnect_loop(start_future))
         try:
             await start_future
         except MqttError as err:
@@ -85,68 +86,93 @@ async def start(self) -> None:
     async def close(self) -> None:
         """Cancels the MQTT loop and shutdown the client library."""
         self._stop = True
-        if self._background_task:
-            self._background_task.cancel()
-            try:
-                await self._background_task
-            except asyncio.CancelledError:
-                pass
-        async with self._client_lock:
-            if self._client:
-                await self._client.close()
+        tasks = [task for task in [self._connection_task, self._reconnect_task] if task]
+        for task in tasks:
+            task.cancel()
+        try:
+            await asyncio.gather(*tasks)
+        except asyncio.CancelledError:
+            pass
 
         self._healthy = False
 
-    async def _run_task(self, start_future: asyncio.Future[None] | None) -> None:
+    async def restart(self) -> None:
+        """Force the session to disconnect and reconnect.
+
+        The active connection task will be cancelled and restarted in the background, retried by
+        the reconnect loop. This is a no-op if there is no active connection.
+        """
+        _LOGGER.info("Forcing MQTT session restart")
+        if self._connection_task:
+            self._connection_task.cancel()
+        else:
+            _LOGGER.debug("No message loop task to cancel")
+
+    async def _run_reconnect_loop(self, start_future: asyncio.Future[None] | None) -> None:
         """Run the MQTT loop."""
         _LOGGER.info("Starting MQTT session")
         while True:
             try:
-                async with self._mqtt_client(self._params) as client:
-                    # Reset backoff once we've successfully connected
-                    self._backoff = MIN_BACKOFF_INTERVAL
-                    self._healthy = True
-                    _LOGGER.info("MQTT Session connected.")
-                    if start_future:
-                        start_future.set_result(None)
-                        start_future = None
-
-                    await self._process_message_loop(client)
-
-            except MqttError as err:
-                if start_future:
-                    _LOGGER.info("MQTT error starting session: %s", err)
-                    start_future.set_exception(err)
-                    return
-                _LOGGER.info("MQTT error: %s", err)
-            except asyncio.CancelledError as err:
-                if start_future:
-                    _LOGGER.debug("MQTT loop was cancelled while starting")
-                    start_future.set_exception(err)
-                _LOGGER.debug("MQTT loop was cancelled")
-                return
-            # Catch exceptions to avoid crashing the loop
-            # and to allow the loop to retry.
-            except Exception as err:
-                # This error is thrown when the MQTT loop is cancelled
-                # and the generator is not stopped.
-                if "generator didn't stop" in str(err) or "generator didn't yield" in str(err):
-                    _LOGGER.debug("MQTT loop was cancelled")
-                    return
-                if start_future:
-                    _LOGGER.error("Uncaught error starting MQTT session: %s", err)
-                    start_future.set_exception(err)
+                self._connection_task = asyncio.create_task(self._run_connection(start_future))
+                await self._connection_task
+            except asyncio.CancelledError:
+                _LOGGER.debug("MQTT connection task cancelled")
+            except Exception:
+                # Exceptions are logged and handled in _run_connection.
+                # There is a special case for exceptions on startup where we return
+                # immediately. Otherwise, we let the reconnect loop retry with
+                # backoff when the reconnect loop is active.
+                if start_future and start_future.done() and start_future.exception():
                     return
-                _LOGGER.exception("Uncaught error during MQTT session: %s", err)
 
             self._healthy = False
+            start_future = None
             if self._stop:
                 _LOGGER.debug("MQTT session closed, stopping retry loop")
                 return
             _LOGGER.info("MQTT session disconnected, retrying in %s seconds", self._backoff.total_seconds())
             await asyncio.sleep(self._backoff.total_seconds())
             self._backoff = min(self._backoff * BACKOFF_MULTIPLIER, MAX_BACKOFF_INTERVAL)
 
+    async def _run_connection(self, start_future: asyncio.Future[None] | None) -> None:
+        """Connect to the MQTT broker and listen for messages.
+
+        This is the primary connection loop for the MQTT session that is
+        long running and processes incoming messages. If the connection
+        is lost, this method will exit.
+        """
+        try:
+            async with self._mqtt_client(self._params) as client:
+                self._backoff = MIN_BACKOFF_INTERVAL
+                self._healthy = True
+                _LOGGER.info("MQTT Session connected.")
+                if start_future and not start_future.done():
+                    start_future.set_result(None)
+
+                _LOGGER.debug("Processing MQTT messages")
+                async for message in client.messages:
+                    _LOGGER.debug("Received message: %s", message)
+                    self._listeners(message.topic.value, message.payload)
+        except MqttError as err:
+            if start_future and not start_future.done():
+                _LOGGER.info("MQTT error starting session: %s", err)
+                start_future.set_exception(err)
+            else:
+                _LOGGER.info("MQTT error: %s", err)
+            raise
+        except Exception as err:
+            # This error is thrown when the MQTT loop is cancelled
+            # and the generator is not stopped.
+            if "generator didn't stop" in str(err) or "generator didn't yield" in str(err):
+                _LOGGER.debug("MQTT loop was cancelled")
+                return
+            if start_future and not start_future.done():
+                _LOGGER.error("Uncaught error starting MQTT session: %s", err)
+                start_future.set_exception(err)
+            else:
+                _LOGGER.exception("Uncaught error during MQTT session: %s", err)
+            raise
+
     @asynccontextmanager
     async def _mqtt_client(self, params: MqttParams) -> aiomqtt.Client:
         """Connect to the MQTT broker and listen for messages."""
@@ -178,12 +204,6 @@ async def _mqtt_client(self, params: MqttParams) -> aiomqtt.Client:
             async with self._client_lock:
                 self._client = None
 
-    async def _process_message_loop(self, client: aiomqtt.Client) -> None:
-        _LOGGER.debug("Processing MQTT messages")
-        async for message in client.messages:
-            _LOGGER.debug("Received message: %s", message)
-            self._listeners(message.topic.value, message.payload)
-
     async def subscribe(self, topic: str, callback: Callable[[bytes], None]) -> Callable[[], None]:
         """Subscribe to messages on the specified topic and invoke the callback for new messages.
 
@@ -271,6 +291,10 @@ async def close(self) -> None:
         """
         await self._session.close()
 
+    async def restart(self) -> None:
+        """Force the session to disconnect and reconnect."""
+        await self._session.restart()
+
 
 async def create_mqtt_session(params: MqttParams) -> MqttSession:
     """Create an MQTT session.

roborock/mqtt/session.py

@@ -54,6 +54,10 @@ async def publish(self, topic: str, message: bytes) -> None:
         This will raise an exception if the message could not be sent.
         """
 
+    @abstractmethod
+    async def restart(self) -> None:
+        """Force the session to disconnect and reconnect."""
+
     @abstractmethod
     async def close(self) -> None:
         """Cancels the mqtt loop"""

tests/conftest.py

@@ -363,6 +363,7 @@ def __init__(self):
         self.connect = AsyncMock(side_effect=self._connect)
         self.close = MagicMock(side_effect=self._close)
         self.protocol_version = LocalProtocolVersion.V1
+        self.restart = AsyncMock()
 
     async def _connect(self) -> None:
         self._is_connected = True

tests/mqtt/test_health_manager.py

@@ -0,0 +1,73 @@
+"""Tests for the health manager."""
+
+import datetime
+from unittest.mock import AsyncMock, patch
+
+from roborock.mqtt.health_manager import HealthManager
+
+
+async def test_health_manager_restart_called_after_timeouts() -> None:
+    """Test that the health manager calls restart after consecutive timeouts."""
+    restart = AsyncMock()
+    health_manager = HealthManager(restart=restart)
+
+    await health_manager.on_timeout()
+    await health_manager.on_timeout()
+    restart.assert_not_called()
+
+    await health_manager.on_timeout()
+    restart.assert_called_once()
+
+
+async def test_health_manager_success_resets_counter() -> None:
+    """Test that a successful message resets the timeout counter."""
+    restart = AsyncMock()
+    health_manager = HealthManager(restart=restart)
+
+    await health_manager.on_timeout()
+    await health_manager.on_timeout()
+    restart.assert_not_called()
+
+    await health_manager.on_success()
+
+    await health_manager.on_timeout()
+    await health_manager.on_timeout()
+    restart.assert_not_called()
+
+    await health_manager.on_timeout()
+    restart.assert_called_once()
+
+
+async def test_cooldown() -> None:
+    """Test that the health manager respects the restart cooldown."""
+    restart = AsyncMock()
+    health_manager = HealthManager(restart=restart)
+
+    with patch("roborock.mqtt.health_manager.datetime") as mock_datetime:
+        now = datetime.datetime(2023, 1, 1, 12, 0, 0)
+        mock_datetime.datetime.now.return_value = now
+
+        # Trigger first restart
+        await health_manager.on_timeout()
+        await health_manager.on_timeout()
+        await health_manager.on_timeout()
+        restart.assert_called_once()
+        restart.reset_mock()
+
+        # Advance time but stay within cooldown (30 mins)
+        mock_datetime.datetime.now.return_value = now + datetime.timedelta(minutes=10)
+
+        # Trigger timeouts again
+        await health_manager.on_timeout()
+        await health_manager.on_timeout()
+        await health_manager.on_timeout()
+        restart.assert_not_called()
+
+        # Advance time past cooldown
+        mock_datetime.datetime.now.return_value = now + datetime.timedelta(minutes=31)
+
+        # Trigger timeouts again
+        await health_manager.on_timeout()
+        await health_manager.on_timeout()
+        await health_manager.on_timeout()
+        restart.assert_called_once()