fix(api): keep provider degradation out of healthz

Co-authored-by: Codex <noreply@openai.com>

backend/crates/gateway-api/src/health.rs

@@ -1,4 +1,4 @@
-//! `/healthz` 对 Core、Store 与 Host worker 健康事实的聚合。
+//! `/healthz` 对 Core、Store 与 Host 关键 worker 健康事实的聚合。
 
 use std::sync::Arc;
 use std::time::Duration;
@@ -6,8 +6,10 @@ use std::time::Duration;
 use axum::{extract::State, http::StatusCode};
 use futures::future::join_all;
 use gateway_core::health::{
-    HealthProbe, HealthState, WorkerHealthSnapshot, WorkerHealthSource, WorkerRuntimeState,
+    HealthProbe, HealthState, WorkerHealthKey, WorkerHealthSnapshot, WorkerHealthSource,
+    WorkerRuntimeState,
 };
+use gateway_core::task::WorkerKind;
 
 use crate::ApiState;
 
@@ -32,7 +34,13 @@ impl HealthStatus {
     }
 
     pub(crate) async fn healthy(&self) -> bool {
-        if !self.workers.snapshot().iter().all(worker_is_healthy) {
+        if !self
+            .workers
+            .snapshot()
+            .iter()
+            .filter(|worker| worker_affects_healthz(worker))
+            .all(worker_is_healthy)
+        {
             return false;
         }
         let checks = self.probes.iter().map(|probe| probe.check());
@@ -54,6 +62,16 @@ pub(crate) async fn healthz(State(state): State<ApiState>) -> StatusCode {
     }
 }
 
+fn worker_affects_healthz(worker: &WorkerHealthSnapshot) -> bool {
+    let WorkerHealthKey::Task(id) = &worker.key else {
+        return false;
+    };
+    !matches!(
+        id.kind(),
+        WorkerKind::OAuthRefresh | WorkerKind::QuotaCatalogHealth
+    )
+}
+
 fn worker_is_healthy(worker: &WorkerHealthSnapshot) -> bool {
     match worker.state {
         WorkerRuntimeState::Disabled | WorkerRuntimeState::Standby => true,

backend/crates/gateway-api/tests/health.rs

@@ -11,7 +11,9 @@ use gateway_core::{
         StartedExecution,
     },
     error::GatewayError,
+    health::{WorkerHealthKey, WorkerHealthSnapshot, WorkerHealthSource, WorkerRuntimeState},
     routing::PublicModelId,
+    task::{WorkerId, WorkerKind},
 };
 use tower::ServiceExt;
 
@@ -31,6 +33,75 @@ async fn healthz_should_return_no_content_when_all_inputs_are_healthy() {
     assert_eq!(response.status(), StatusCode::NO_CONTENT);
 }
 
+#[tokio::test]
+async fn healthz_should_ignore_provider_maintenance_worker_failure() {
+    let worker_health = StaticWorkerHealth(vec![worker_snapshot(
+        WorkerKind::QuotaCatalogHealth,
+        WorkerRuntimeState::BackingOff,
+    )]);
+    let response = crate::openai::api_router_with_worker_health(
+        Arc::new(UnusedExecution),
+        Arc::new(worker_health),
+    )
+    .await
+    .oneshot(
+        Request::builder()
+            .uri("/healthz")
+            .body(Body::empty())
+            .expect("health request"),
+    )
+    .await
+    .expect("health response");
+
+    assert_eq!(response.status(), StatusCode::NO_CONTENT);
+}
+
+#[tokio::test]
+async fn healthz_should_reject_critical_worker_failure() {
+    let worker_health = StaticWorkerHealth(vec![worker_snapshot(
+        WorkerKind::RuntimeSnapshotReconciliation,
+        WorkerRuntimeState::BackingOff,
+    )]);
+    let response = crate::openai::api_router_with_worker_health(
+        Arc::new(UnusedExecution),
+        Arc::new(worker_health),
+    )
+    .await
+    .oneshot(
+        Request::builder()
+            .uri("/healthz")
+            .body(Body::empty())
+            .expect("health request"),
+    )
+    .await
+    .expect("health response");
+
+    assert_eq!(response.status(), StatusCode::SERVICE_UNAVAILABLE);
+}
+
+#[derive(Clone)]
+struct StaticWorkerHealth(Vec<WorkerHealthSnapshot>);
+
+impl WorkerHealthSource for StaticWorkerHealth {
+    fn snapshot(&self) -> Vec<WorkerHealthSnapshot> {
+        self.0.clone()
+    }
+}
+
+fn worker_snapshot(kind: WorkerKind, state: WorkerRuntimeState) -> WorkerHealthSnapshot {
+    let id = WorkerId::try_new(kind, "health-test").expect("worker ID");
+    WorkerHealthSnapshot {
+        key: WorkerHealthKey::Task(id),
+        state,
+        consecutive_failures: 1,
+        completed_cycles: 0,
+        last_fencing_token: None,
+        last_success_at: None,
+        last_failure_at: None,
+        last_error: Some("test worker failure".to_owned()),
+    }
+}
+
 struct UnusedExecution;
 
 impl ExecutionService for UnusedExecution {

backend/crates/gateway-api/tests/openai/mod.rs

@@ -44,9 +44,29 @@ pub(super) async fn api_router(execution: Arc<dyn ExecutionService>) -> axum::Ro
     api_router_with_origins(execution, Vec::new()).await
 }
 
+pub(super) async fn api_router_with_worker_health(
+    execution: Arc<dyn ExecutionService>,
+    worker_health: Arc<dyn WorkerHealthSource>,
+) -> axum::Router {
+    api_router_with_origins_and_worker_health(execution, Vec::new(), worker_health).await
+}
+
 pub(super) async fn api_router_with_origins(
     execution: Arc<dyn ExecutionService>,
     cors_allowed_origins: Vec<String>,
+) -> axum::Router {
+    api_router_with_origins_and_worker_health(
+        execution,
+        cors_allowed_origins,
+        Arc::new(EmptyWorkerHealth),
+    )
+    .await
+}
+
+async fn api_router_with_origins_and_worker_health(
+    execution: Arc<dyn ExecutionService>,
+    cors_allowed_origins: Vec<String>,
+    worker_health: Arc<dyn WorkerHealthSource>,
 ) -> axum::Router {
     let admin = crate::admin::AdminTestFixture::new().await;
     gateway_api::initialize(
@@ -59,7 +79,7 @@ pub(super) async fn api_router_with_origins(
         execution,
         admin.services,
         Vec::new(),
-        Arc::new(EmptyWorkerHealth),
+        worker_health,
         Arc::new(TestLifecycle::default()),
     )
     .expect("API bundle")