fix(proxy): clear stale session affinity after failures

Author: DeliciousBuding

auth/session_affinity_test.go

@@ -123,3 +123,27 @@ func TestWaitForSessionAvailableRespectsExcludeSet(t *testing.T) {
 		t.Fatalf("proxyURL = %q, want empty fallback proxy", proxyURL)
 	}
 }
+
+func TestUnbindSessionAffinityRemovesMatchingBinding(t *testing.T) {
+	store := &Store{
+		accounts: []*Account{
+			{DBID: 1, AccessToken: "tok-1"},
+			{DBID: 2, AccessToken: "tok-2"},
+		},
+		maxConcurrency: 1,
+	}
+	store.bindSessionAffinity("session-1", store.accounts[1], "http://proxy-2")
+
+	store.UnbindSessionAffinity("session-1", 2)
+
+	acc, proxyURL := store.NextForSession("session-1", nil)
+	if acc == nil {
+		t.Fatal("expected fallback account")
+	}
+	if acc.DBID != 1 {
+		t.Fatalf("account DBID = %d, want %d", acc.DBID, 1)
+	}
+	if proxyURL != "" {
+		t.Fatalf("proxyURL = %q, want empty fallback proxy", proxyURL)
+	}
+}

auth/store.go

@@ -1313,6 +1313,23 @@ func (s *Store) bindSessionAffinity(key string, account *Account, proxyURL strin
 	s.sessionMu.Unlock()
 }
 
+// UnbindSessionAffinity removes a session binding when it still points to the failed account.
+func (s *Store) UnbindSessionAffinity(key string, accountID int64) {
+	if s == nil || accountID == 0 {
+		return
+	}
+	key = strings.TrimSpace(key)
+	if key == "" {
+		return
+	}
+
+	s.sessionMu.Lock()
+	if binding, ok := s.sessionBindings[key]; ok && binding.accountID == accountID {
+		delete(s.sessionBindings, key)
+	}
+	s.sessionMu.Unlock()
+}
+
 // NextForSession 优先复用已绑定的账号和代理，失败时回退到普通选号。
 func (s *Store) NextForSession(key string, exclude map[int64]bool) (*Account, string) {
 	if s == nil {

proxy/handler.go

@@ -497,6 +497,7 @@ func (h *Handler) Responses(c *gin.Context) {
 				h.store.ReportRequestFailure(account, kind, time.Duration(durationMs)*time.Millisecond)
 			}
 			h.store.Release(account)
+			h.store.UnbindSessionAffinity(sessionID, account.ID())
 			excludeAccounts[account.ID()] = true
 
 			// 不可重试的结构化错误直接返回
@@ -520,6 +521,7 @@ func (h *Handler) Responses(c *gin.Context) {
 			errBody, _ := io.ReadAll(resp.Body)
 			resp.Body.Close()
 			h.store.Release(account)
+			h.store.UnbindSessionAffinity(sessionID, account.ID())
 			excludeAccounts[account.ID()] = true
 
 			log.Printf("上游返回错误 (attempt %d, status %d): %s", attempt+1, resp.StatusCode, string(errBody))
@@ -866,6 +868,7 @@ func (h *Handler) ChatCompletions(c *gin.Context) {
 				h.store.ReportRequestFailure(account, kind, time.Duration(durationMs)*time.Millisecond)
 			}
 			h.store.Release(account)
+			h.store.UnbindSessionAffinity(sessionID, account.ID())
 			excludeAccounts[account.ID()] = true
 
 			// 不可重试的结构化错误直接返回
@@ -889,6 +892,7 @@ func (h *Handler) ChatCompletions(c *gin.Context) {
 			errBody, _ := io.ReadAll(resp.Body)
 			resp.Body.Close()
 			h.store.Release(account)
+			h.store.UnbindSessionAffinity(sessionID, account.ID())
 			excludeAccounts[account.ID()] = true
 
 			log.Printf("上游返回错误 (attempt %d, status %d): %s", attempt+1, resp.StatusCode, string(errBody))

proxy/handler_anthropic.go

@@ -165,6 +165,7 @@ func (h *Handler) Messages(c *gin.Context) {
 				h.store.ReportRequestFailure(account, kind, time.Duration(durationMs)*time.Millisecond)
 			}
 			h.store.Release(account)
+			h.store.UnbindSessionAffinity(sessionID, account.ID())
 			excludeAccounts[account.ID()] = true
 
 			if !IsRetryableError(reqErr) && classifyTransportFailure(reqErr) == "" {
@@ -187,6 +188,7 @@ func (h *Handler) Messages(c *gin.Context) {
 			errBody, _ := io.ReadAll(resp.Body)
 			resp.Body.Close()
 			h.store.Release(account)
+			h.store.UnbindSessionAffinity(sessionID, account.ID())
 			excludeAccounts[account.ID()] = true
 
 			log.Printf("上游返回错误 (attempt %d, status %d, /v1/messages): %s", attempt+1, resp.StatusCode, string(errBody))