fix(bridge): 429 Rate Limit 무한 루프 방지 — 지수 백오프 + Collector 폴링 보호 + rate limit 완화

bridge.py

@@ -173,6 +173,12 @@ class RemoteTransport(BridgeTransport):
         self._consecutive_failures = 0
         self._max_failures_before_warning = 3
 
+        # Rate limit backoff
+        self._rate_limited_until = 0.0  # timestamp until which we should not send requests
+        self._backoff_seconds = 0.0  # current backoff duration (exponential)
+        self._BACKOFF_BASE = 1.0
+        self._BACKOFF_MAX = 60.0
+
         # Retry queue: list of (method, path, data) tuples
         self._retry_queue: list[tuple[str, str, dict | None]] = []
         self._retry_queue_max = 100
@@ -194,8 +200,35 @@ class RemoteTransport(BridgeTransport):
         if self._session and not self._session.closed:
             await self._session.close()
 
+    @property
+    def is_rate_limited(self) -> bool:
+        """Check if we are currently in a rate-limit backoff period."""
+        return time.time() < self._rate_limited_until
+
+    def _apply_backoff(self, retry_after: float = 0):
+        """Apply exponential backoff for rate limiting."""
+        if retry_after > 0:
+            self._backoff_seconds = min(retry_after, self._BACKOFF_MAX)
+        else:
+            if self._backoff_seconds == 0:
+                self._backoff_seconds = self._BACKOFF_BASE
+            else:
+                self._backoff_seconds = min(self._backoff_seconds * 2, self._BACKOFF_MAX)
+        self._rate_limited_until = time.time() + self._backoff_seconds
+        logger.warning(f"RemoteTransport: backing off {self._backoff_seconds:.0f}s (until +{self._backoff_seconds:.0f}s)")
+
+    def _reset_backoff(self):
+        """Reset backoff after a successful request."""
+        if self._backoff_seconds > 0:
+            self._backoff_seconds = 0
+            self._rate_limited_until = 0
+
     async def _arequest(self, method: str, path: str, data: dict | None = None) -> dict | None:
         """Async non-blocking HTTP request to Gateway API."""
+        # Skip if in backoff period (except health checks)
+        if self.is_rate_limited and path != "/health":
+            return None
+
         session = await self._get_session()
         url = f"{self.base_url}{path}"
         try:
@@ -207,7 +240,8 @@ class RemoteTransport(BridgeTransport):
                     if resp.status == 401:
                         logger.error("RemoteTransport: 401 Unauthorized — check GATEWAY_API_KEY")
                     elif resp.status == 429:
-                        logger.warning("RemoteTransport: 429 Rate limited")
+                        retry_after = float(resp.headers.get("Retry-After", 0))
+                        self._apply_backoff(retry_after)
                     else:
                         logger.warning(f"RemoteTransport: {method} {path} → {resp.status}")
                     return None
@@ -216,6 +250,7 @@ class RemoteTransport(BridgeTransport):
                     logger.info("RemoteTransport: ✅ Gateway connected")
                 self.connected = True
                 self._consecutive_failures = 0
+                self._reset_backoff()
                 return result
         except Exception as e:
             self._consecutive_failures += 1
@@ -224,6 +259,9 @@ class RemoteTransport(BridgeTransport):
             elif self._consecutive_failures < self._max_failures_before_warning:
                 logger.warning(f"RemoteTransport: {method} {path} → {e}")
             self.connected = False
+            # Apply backoff on connection failures too
+            if self._consecutive_failures >= self._max_failures_before_warning:
+                self._apply_backoff()
             return None
 
     async def _arequest_retry(self, method: str, path: str, data: dict | None = None) -> dict | None: