Limit max delay between retries to 15 min (#264)

src/petals/client/routing/sequence_manager.py

@@ -40,6 +40,7 @@ class RemoteSequenceManager:
     :param update_period: by default, refresh DHT information once in this many seconds
     :param request_timeout: float, in seconds, default timeout for RPC forward/backward/inference requests
     :param min_backoff: after a repeated failure, sleep for this many seconds times 2 ^ (num_failures - 1)
+    :param max_backoff: limit maximal sleep time between retries to this value
     :param ban_timeout: when a remote peer fails to respond, prevent routing to that peer for this many seconds
     :param sequence_info: optionally, specify pre-generated sequence info. by default, create a new one using dht
     :param rpc_info: optionally, specify rpc info (communicated tensor shapes and compression) to save time
@@ -59,6 +60,7 @@ class RemoteSequenceManager:
         request_timeout: float = 30,
         max_retries: Optional[int] = None,
         min_backoff: float = 1,
+        max_backoff: float = 15 * 60,
         ban_timeout: float = 15,
         sequence_info: Optional[RemoteSequenceInfo] = None,
         rpc_info: Optional[dict] = None,
@@ -70,7 +72,7 @@ class RemoteSequenceManager:
         assert len(block_uids) > 0, "Sequences must contain at least one block"
         self.dht, self.p2p = dht, p2p
         self.request_timeout, self.max_retries = request_timeout, max_retries
-        self.ban_timeout, self.min_backoff = ban_timeout, min_backoff
+        self.ban_timeout, self.min_backoff, self.max_backoff = ban_timeout, min_backoff, max_backoff
         self.lock_changes = threading.Lock()
         self._thread = _SequenceManagerUpdateThread(update_period, WeakMethod(self._update))
         self.policy = NoSpendingPolicy()
@@ -156,6 +158,7 @@ class RemoteSequenceManager:
             request_timeout=self.request_timeout,
             ban_timeout=self.ban_timeout,
             min_backoff=self.min_backoff,
+            max_backoff=self.max_backoff,
             sequence_info=self.sequence_info[ix],
             rpc_info=self._rpc_info,
             allowed_servers=self.allowed_servers,
@@ -296,7 +299,7 @@ class RemoteSequenceManager:
     def get_retry_delay(self, attempt_no: int) -> float:
         if attempt_no == 0:
             return 0
-        return self.min_backoff * 2 ** (attempt_no - 1)
+        return min(self.min_backoff * 2 ** (attempt_no - 1), self.max_backoff)
 
     def get_request_metadata(self, protocol: str, *args, **kwargs) -> Optional[Dict[str, Any]]:
         """