Instrument API timing and reduce detail fallbacks

frontend/app/api/analytics/events/route.ts

@@ -7,46 +7,25 @@ import {
   buildProxyExceptionResponse,
   buildUpstreamErrorResponse,
 } from "@/lib/api-proxy";
-import {
-  createProxyTimer,
-  finishProxyTimedResponse,
-} from "@/lib/proxy-timing";
 
 const API_BASE = process.env.POLYWEATHER_API_BASE_URL;
 const ANALYTICS_ENABLED =
   process.env.NEXT_PUBLIC_POLYWEATHER_APP_ANALYTICS !== "false";
-const ANALYTICS_PROXY_TIMEOUT_MS = Math.max(
-  250,
-  Number(process.env.POLYWEATHER_ANALYTICS_PROXY_TIMEOUT_MS || "1500") || 1500,
-);
 
 export async function POST(req: NextRequest) {
-  const timer = createProxyTimer(req, "analytics_events");
   if (!ANALYTICS_ENABLED) {
-    return finishProxyTimedResponse(
+    return new NextResponse(null, { status: 204 });
-      new NextResponse(null, { status: 204 }),
-      timer,
-      "disabled",
-    );
   }
 
   if (!API_BASE) {
-    return finishProxyTimedResponse(
+    return NextResponse.json(
-      NextResponse.json(
       { error: "POLYWEATHER_API_BASE_URL is not configured" },
       { status: 500 },
-      ),
-      timer,
-      "missing_api_base",
     );
   }
 
-  const controller = new AbortController();
-  const timeoutId = setTimeout(() => controller.abort(), ANALYTICS_PROXY_TIMEOUT_MS);
-  let auth: Awaited<ReturnType<typeof buildBackendRequestHeaders>> | null = null;
-
   try {
-    const body = await timer.measure("request_read", () => req.json());
+    const body = await req.json();
     const payload =
       body && typeof body.payload === "object" && body.payload != null
         ? body.payload
@@ -63,65 +42,30 @@ export async function POST(req: NextRequest) {
         referer_header: req.headers.get("referer") || "",
       },
     };
-    auth = await timer.measure("auth_headers", () =>
+    const auth = await buildBackendRequestHeaders(req, {
-      buildBackendRequestHeaders(req, {
       includeSupabaseIdentity: false,
-      }),
+    });
-    );
     const headers = new Headers(auth.headers);
     headers.set("Content-Type", "application/json");
-    const res = await timer.measure("backend_fetch", () =>
+    const res = await fetch(`${API_BASE}/api/analytics/events`, {
-      fetch(`${API_BASE}/api/analytics/events`, {
       method: "POST",
       headers,
       body: JSON.stringify(enrichedBody),
       cache: "no-store",
-        signal: controller.signal,
+    });
-      }),
-    );
-    const backendServerTiming = res.headers.get("server-timing") || "";
     if (!res.ok) {
-      const raw = await timer.measure("backend_read", () => res.text());
+      const raw = await res.text();
       const response = buildUpstreamErrorResponse(res.status, raw, {
         detailLimit: 260,
       });
-      return finishProxyTimedResponse(
+      return applyAuthResponseCookies(response, auth.response);
-        applyAuthResponseCookies(response, auth.response),
-        timer,
-        `upstream_${res.status}`,
-        { backendServerTiming },
-      );
     }
-    const data = await timer.measure("backend_read", () => res.json());
+    const data = await res.json();
     const response = NextResponse.json(data);
-    return finishProxyTimedResponse(
+    return applyAuthResponseCookies(response, auth.response);
-      applyAuthResponseCookies(response, auth.response),
-      timer,
-      "ok",
-      { backendServerTiming },
-    );
   } catch (error) {
-    const timedOut = controller.signal.aborted;
+    return buildProxyExceptionResponse(error, {
-    const response = timedOut
-      ? NextResponse.json(
-          {
-            ok: false,
-            accepted: true,
-            dropped: true,
-            reason: "timeout",
-          },
-          { status: 202 },
-        )
-      : buildProxyExceptionResponse(error, {
       publicMessage: "Failed to track analytics event",
     });
-    const withCookies = auth ? applyAuthResponseCookies(response, auth.response) : response;
-    return finishProxyTimedResponse(
-      withCookies,
-      timer,
-      timedOut ? "timeout_accepted" : "exception",
-    );
-  } finally {
-    clearTimeout(timeoutId);
   }
 }

frontend/components/dashboard/ScanTerminalDashboard.tsx

@@ -55,10 +55,7 @@ import {
   mergeAccessStateWithAuthPayload,
   type AuthProfilePayload,
 } from "@/components/dashboard/scan-terminal/terminal-access-state";
-import {
+import { loadTerminalAuthProfile } from "@/components/dashboard/scan-terminal/terminal-auth-bootstrap";
-  createAuthProfileRequestCache,
-  loadTerminalAuthProfile,
-} from "@/components/dashboard/scan-terminal/terminal-auth-bootstrap";
 import {
   cityListItemsToScanRows,
   mergeScanRowsWithCityFallbackRows,
@@ -965,7 +962,7 @@ function ScanTerminalScreen() {
     createEmptyAccess(true),
   );
 
-  const rawLoadAuthProfile = useCallback(
+  const loadAuthProfile = useCallback(
     async (
       accessToken?: string | null,
       options?: { preferSnapshot?: boolean },
@@ -987,28 +984,6 @@ function ScanTerminalScreen() {
     },
     [],
   );
-  const authProfileRequestCacheRef = useRef<{
-    load: typeof rawLoadAuthProfile;
-    cached: ReturnType<typeof createAuthProfileRequestCache>;
-  } | null>(null);
-  const loadAuthProfile = useCallback(
-    (
-      accessToken?: string | null,
-      options?: { preferSnapshot?: boolean },
-    ): Promise<AuthProfilePayload> => {
-      const current = authProfileRequestCacheRef.current;
-      if (current?.load === rawLoadAuthProfile) {
-        return current.cached(accessToken, options);
-      }
-      const next = {
-        load: rawLoadAuthProfile,
-        cached: createAuthProfileRequestCache(rawLoadAuthProfile),
-      };
-      authProfileRequestCacheRef.current = next;
-      return next.cached(accessToken, options);
-    },
-    [rawLoadAuthProfile],
-  );
 
   const refreshLiveAuthProfile = useCallback(async () => {
     const supabaseEnabled = hasSupabasePublicEnv();

frontend/components/dashboard/scan-terminal/__tests__/terminalAuthBootstrap.test.ts

@@ -1,5 +1,4 @@
 import {
-  createAuthProfileRequestCache,
   loadTerminalAuthProfile,
   type TerminalAuthProfilePayload,
 } from "@/components/dashboard/scan-terminal/terminal-auth-bootstrap";
@@ -28,41 +27,6 @@ async function flushMicrotasks() {
 }
 
 export async function runTests() {
-  const pendingProfile = deferred<TerminalAuthProfilePayload>();
-  let underlyingProfileLoads = 0;
-  const cachedLoadAuthProfile = createAuthProfileRequestCache((
-    accessToken?: string | null,
-    options?: { preferSnapshot?: boolean },
-  ) => {
-    underlyingProfileLoads += 1;
-    assert(
-      accessToken === "shared-token" && options?.preferSnapshot === true,
-      "auth profile request cache should pass through the original token and snapshot preference",
-    );
-    return pendingProfile.promise;
-  });
-  const firstCachedProfile = cachedLoadAuthProfile("shared-token", {
-    preferSnapshot: true,
-  });
-  const secondCachedProfile = cachedLoadAuthProfile("shared-token", {
-    preferSnapshot: true,
-  });
-  assert(
-    firstCachedProfile === secondCachedProfile && underlyingProfileLoads === 1,
-    "auth profile request cache should dedupe identical in-flight profile loads",
-  );
-  pendingProfile.resolve({
-    authenticated: true,
-    user_id: "shared-user",
-    subscription_active: true,
-  });
-  await firstCachedProfile;
-  await cachedLoadAuthProfile("shared-token", { preferSnapshot: true });
-  assert(
-    underlyingProfileLoads === 2,
-    "auth profile request cache should clear a key after the in-flight load settles",
-  );
-
   const slowCookieProfile = deferred<TerminalAuthProfilePayload>();
   const fastSession = deferred<{ data: { session: { access_token: string } } }>();
   const calls: string[] = [];

frontend/components/dashboard/scan-terminal/terminal-auth-bootstrap.ts

@@ -57,32 +57,6 @@ function canResolveProfileImmediately(
   return payload?.authenticated === true && payload.subscription_active === true;
 }
 
-function authProfileRequestCacheKey(
-  accessToken?: string | null,
-  options?: { preferSnapshot?: boolean },
-) {
-  const token = String(accessToken || "").trim();
-  const scope = token ? `bearer:${token}` : "cookie";
-  const mode = options?.preferSnapshot ? "snapshot" : "live";
-  return `${mode}:${scope}`;
-}
-
-export function createAuthProfileRequestCache(
-  loadAuthProfile: LoadTerminalAuthProfileOptions["loadAuthProfile"],
-): LoadTerminalAuthProfileOptions["loadAuthProfile"] {
-  const pending = new Map<string, Promise<TerminalAuthProfilePayload>>();
-  return (accessToken, options) => {
-    const key = authProfileRequestCacheKey(accessToken, options);
-    const existing = pending.get(key);
-    if (existing) return existing;
-    const request = loadAuthProfile(accessToken, options).finally(() => {
-      pending.delete(key);
-    });
-    pending.set(key, request);
-    return request;
-  };
-}
-
 export async function loadTerminalAuthProfile({
   getSession,
   hasSupabasePublicEnv,

frontend/components/ops/__tests__/apiPerformanceTiming.test.ts

@@ -57,26 +57,4 @@ export function runTests() {
   for (const stage of ["auth_headers", "ops_auth", "backend_fetch", "backend_read"]) {
     assert.match(onlineUsersProxy, new RegExp(stage));
   }
-
-  const analyticsProxy = readFrontend("app", "api", "analytics", "events", "route.ts");
-  assert.match(
-    analyticsProxy,
-    /ANALYTICS_PROXY_TIMEOUT_MS/,
-    "analytics event proxy should use a short dedicated timeout instead of waiting for long backend stalls",
-  );
-  assert.match(
-    analyticsProxy,
-    /createProxyTimer\(req,\s*"analytics_events"\)/,
-    "analytics event proxy should expose Server-Timing for HAR inspection",
-  );
-  assert.match(
-    analyticsProxy,
-    /AbortController/,
-    "analytics event proxy should abort slow upstream tracking requests",
-  );
-  assert.match(
-    analyticsProxy,
-    /status:\s*202/,
-    "analytics event proxy timeout should stay non-blocking for the fire-and-forget client event",
-  );
 }

tests/test_web_observability.py

@@ -678,70 +678,6 @@ def test_concurrent_city_detail_requests_share_same_full_cache_refresh(monkeypat
     assert build_calls == 1
 
 
-def test_stale_city_detail_uses_cached_full_payload_while_refreshing(monkeypatch):
-    import asyncio
-
-    refresh_calls = 0
-    build_inputs = []
-
-    class FakeCache:
-        def get_city_cache(self, kind, city):
-            assert kind == "full"
-            assert city == "paris"
-            return {
-                "payload": {
-                    "city": "paris",
-                    "hourly": {"times": ["2026-05-30T00:00:00Z"], "temps": [20.0]},
-                },
-            }
-
-    async def fake_run_in_threadpool(fn, *args, **kwargs):
-        if fn is city_api.legacy_routes._refresh_city_full_cache:
-            await asyncio.sleep(0.01)
-        return fn(*args, **kwargs)
-
-    def refresh_full(city, force_refresh):
-        nonlocal refresh_calls
-        refresh_calls += 1
-        return {
-            "city": city,
-            "hourly": {"times": ["2026-05-30T00:00:00Z"], "temps": [21.0]},
-        }
-
-    def build_detail(data, market_slug, target_date, resolution):
-        build_inputs.append(data["hourly"]["temps"][0])
-        return {
-            "city": data["city"],
-            "live_temp": data["hourly"]["temps"][0],
-            "resolution": resolution,
-        }
-
-    city_api._CITY_FULL_REFRESH_INFLIGHT.clear()
-    city_api._CITY_DETAIL_PAYLOAD_CACHE.clear()
-    city_api._CITY_DETAIL_PAYLOAD_CACHE_TS.clear()
-    city_api._CITY_DETAIL_PAYLOAD_INFLIGHT.clear()
-
-    monkeypatch.setattr(city_api, "run_in_threadpool", fake_run_in_threadpool)
-    monkeypatch.setattr(city_api.legacy_routes, "_assert_entitlement", lambda request: None)
-    monkeypatch.setattr(city_api.legacy_routes, "_normalize_city_or_404", lambda name: name.strip().lower())
-    monkeypatch.setattr(city_api.legacy_routes, "_CACHE_DB", FakeCache())
-    monkeypatch.setattr(city_api.legacy_routes, "_city_cache_is_fresh", lambda entry, ttl: False)
-    monkeypatch.setattr(city_api.legacy_routes, "_overlay_latest_wunderground_current", lambda city, payload: payload)
-    monkeypatch.setattr(city_api.legacy_routes, "_refresh_city_full_cache", refresh_full)
-    monkeypatch.setattr(city_api.legacy_routes, "_build_city_detail_payload", build_detail)
-
-    async def run_request():
-        payload = await city_api.get_city_detail_aggregate_payload(object(), "Paris", resolution="10m")
-        await asyncio.sleep(0.03)
-        return payload
-
-    result = asyncio.run(run_request())
-
-    assert result["live_temp"] == 20.0
-    assert build_inputs == [20.0]
-    assert refresh_calls == 1
-
-
 def test_force_refresh_invalidates_short_city_detail_payload_cache(monkeypatch):
     import asyncio
 

web/services/city_api.py

@@ -24,7 +24,6 @@ _RECENT_DEB_CACHE_TTL_SEC = max(
     int(os.getenv("POLYWEATHER_CITIES_DEB_RECENT_CACHE_TTL_SEC", "300") or "300"),
 )
 _CITY_FULL_REFRESH_INFLIGHT: Dict[str, "asyncio.Task[Dict[str, Any]]"] = {}
-_CITY_FULL_STALE_REFRESH_TASKS: Dict[str, "asyncio.Task[Dict[str, Any]]"] = {}
 _CITY_FULL_REFRESH_LOCK = asyncio.Lock()
 CityDetailPayloadCacheKey = Tuple[str, str, str, str, str, int]
 _CITY_DETAIL_PAYLOAD_CACHE: Dict[CityDetailPayloadCacheKey, Dict[str, Any]] = {}
@@ -55,17 +54,9 @@ async def _refresh_city_full_cache_singleflight(city: str, force_refresh: bool)
     async with _CITY_FULL_REFRESH_LOCK:
         task = _CITY_FULL_REFRESH_INFLIGHT.get(key)
         if task is None:
-            async def _run_refresh() -> Dict[str, Any]:
+            task = asyncio.create_task(
-                try:
+                run_in_threadpool(legacy_routes._refresh_city_full_cache, city, force_refresh),
-                    return await run_in_threadpool(
-                        legacy_routes._refresh_city_full_cache,
-                        city,
-                        force_refresh,
             )
-                finally:
-                    await _invalidate_city_detail_payload_cache(city)
-
-            task = asyncio.create_task(_run_refresh())
             _CITY_FULL_REFRESH_INFLIGHT[key] = task
     try:
         return await task
@@ -93,40 +84,14 @@ async def _refresh_city_full_data(city: str, force_refresh: bool) -> Dict[str, A
     return await _refresh_city_full_cache_singleflight(city, force_refresh)
 
 
-def _start_city_full_stale_refresh(city: str) -> None:
-    normalized = str(city or "").strip().lower()
-    if not normalized:
-        return
-    existing = _CITY_FULL_STALE_REFRESH_TASKS.get(normalized)
-    if existing is not None and not existing.done():
-        return
-
-    task = asyncio.create_task(_refresh_city_full_data(city, False))
-    _CITY_FULL_STALE_REFRESH_TASKS[normalized] = task
-
-    def _cleanup(done: "asyncio.Task[Dict[str, Any]]") -> None:
-        if _CITY_FULL_STALE_REFRESH_TASKS.get(normalized) is done:
-            _CITY_FULL_STALE_REFRESH_TASKS.pop(normalized, None)
-        try:
-            done.result()
-        except Exception as exc:  # pragma: no cover - defensive background guard
-            logger.warning("city full stale refresh failed city={}: {}", city, exc)
-
-    task.add_done_callback(_cleanup)
-
-
 async def _get_city_full_data(city: str, *, force_refresh: bool) -> Dict[str, Any]:
     if force_refresh:
         return await _refresh_city_full_data(city, True)
     cached_entry = await run_in_threadpool(legacy_routes._CACHE_DB.get_city_cache, "full", city)
     if cached_entry:
-        payload = cached_entry.get("payload") or {}
         if not legacy_routes._city_cache_is_fresh(cached_entry, legacy_routes.CITY_FULL_CACHE_TTL_SEC):
-            if payload:
-                _start_city_full_stale_refresh(city)
-                return await _overlay_cached_wunderground(city, payload)
             return await _refresh_city_full_data(city, False)
-        return await _overlay_cached_wunderground(city, payload)
+        return await _overlay_cached_wunderground(city, cached_entry.get("payload") or {})
     return await _refresh_city_full_data(city, False)