fix(ollama): cooldown provider health probes

apps/api/src/services/ollama_endpoint_circuit_breaker.py

@@ -1,9 +1,9 @@
 """
 Lightweight in-process cooldown for noisy Ollama endpoint failures.
 
-This does not change ADR-110 policy order. It only suppresses endpoints that
-just failed for short-lived high-volume callers such as embedding/RAG, while
-leaving health checks and failover status free to probe the full topology.
+This does not change ADR-110 policy order. It suppresses endpoints that just
+failed for short-lived callers while still returning explicit offline/cooldown
+state to health and route-status surfaces.
 """
 
 from __future__ import annotations
@@ -60,6 +60,26 @@ def is_ollama_endpoint_blocked(url: str, *, now: float | None = None) -> bool:
     return True
 
 
+def get_ollama_endpoint_cooldown_remaining_seconds(
+    url: str,
+    *,
+    now: float | None = None,
+) -> float:
+    """Return remaining cooldown seconds for display/debug surfaces."""
+    if not url:
+        return 0.0
+    current_time = time.monotonic() if now is None else now
+    normalized = _normalize_url(url)
+    blocked_until = _blocked_until_by_url.get(normalized)
+    if blocked_until is None:
+        return 0.0
+    remaining = blocked_until - current_time
+    if remaining <= 0:
+        _blocked_until_by_url.pop(normalized, None)
+        return 0.0
+    return remaining
+
+
 def filter_ollama_urls_with_cooldown(
     urls: Iterable[str],
     *,

apps/api/src/services/ollama_health_monitor.py

@@ -29,6 +29,11 @@ import httpx
 import structlog
 
 from src.core.config import get_settings
+from src.services.ollama_endpoint_circuit_breaker import (
+    get_ollama_endpoint_cooldown_remaining_seconds,
+    record_ollama_endpoint_failure,
+    record_ollama_endpoint_success,
+)
 
 logger = structlog.get_logger(__name__)
 
@@ -206,9 +211,21 @@ class OllamaHealthMonitor:
 
     async def _run_checks(self, host: str) -> HealthReport:
         """依序執行三層檢查"""
+        cooldown_remaining = get_ollama_endpoint_cooldown_remaining_seconds(host)
+        if cooldown_remaining > 0:
+            return HealthReport(
+                status=HealthStatus.OFFLINE,
+                host=host,
+                reason=(
+                    "recent_endpoint_failure_cooldown:"
+                    f"{cooldown_remaining:.0f}s"
+                ),
+            )
+
         # 層 1：連通性
         connectivity_ok = await self._check_connectivity(host)
         if not connectivity_ok:
+            record_ollama_endpoint_failure(host)
             return HealthReport(
                 status=HealthStatus.OFFLINE,
                 host=host,
@@ -217,6 +234,7 @@ class OllamaHealthMonitor:
 
         # 層 2：推理測試
         report = await self._check_inference(host)
+        record_ollama_endpoint_success(host)
         return report
 
     async def _check_connectivity(self, host: str) -> bool: