fix(observability): 治理SSE慢请求虚报、客户端取消日志污染、退款重试刷屏与会话计数慢查询

backend/internal/database/gorm_logger.go

@@ -72,9 +72,12 @@ func (l *structuredGormLogger) Trace(ctx context.Context, begin time.Time, query
 	}
 	elapsed := time.Since(begin)
 	switch {
-	case err != nil && !errors.Is(err, gorm.ErrRecordNotFound) && l.level >= gormLogger.Error:
+	case err != nil && !errors.Is(err, gorm.ErrRecordNotFound) && !errors.Is(err, context.Canceled) && l.level >= gormLogger.Error:
 		sql, rows := query()
 		l.withContext(ctx).Error("数据库查询失败", queryFields(sql, rows, elapsed, err)...)
+	case errors.Is(err, context.Canceled) && l.level >= gormLogger.Info:
+		sql, rows := query()
+		l.withContext(ctx).Debug("数据库查询被客户端取消", queryFields(sql, rows, elapsed, err)...)
 	case elapsed >= l.slowThreshold && l.level >= gormLogger.Warn:
 		sql, rows := query()
 		l.withContext(ctx).Warn("数据库慢查询", queryFields(sql, rows, elapsed, nil)...)

backend/internal/jobs/refundretry/job.go

@@ -123,7 +123,7 @@ func (j *Job) run(ctx context.Context) {
 	if err != nil {
 		j.logger.Warn("退款重试任务扫描缺失退款单失败", zap.Error(err))
 	}
-	if processed > 0 || missing > 0 {
+	if processed > 0 || rebuilt > 0 {
 		j.logger.Info("退款重试任务处理完成",
 			zap.Int("processed", processed),
 			zap.Int("missing_refund_orders", missing),

backend/internal/middleware/request_logger.go

@@ -1,6 +1,8 @@
 package middleware
 
 import (
+	"context"
+	"errors"
 	"net/http"
 	"strings"
 	"time"
@@ -72,6 +74,10 @@ func RequestLogger(logger *zap.Logger) gin.HandlerFunc {
 		}
 
 		switch {
+		case errors.Is(c.Request.Context().Err(), context.Canceled):
+			if logger.Core().Enabled(zap.DebugLevel) {
+				logger.Debug("HTTP 客户端中断连接", fields...)
+			}
 		case status >= 500:
 			logger.Error("HTTP 请求失败", fields...)
 		case status == http.StatusTooManyRequests:
@@ -113,7 +119,7 @@ func shouldSkipHTTPLog(path, route string, status int, latencyMs float64) bool {
 		return false
 	}
 	// SSE 的请求耗时就是连接存活时间，由 chathub 单独记录连接生命周期。
-	if isChatSSEPath(path, route) {
+	if isSSEPath(path, route) {
 		return true
 	}
 	if latencyMs >= slowRequestThresholdMs {
@@ -122,9 +128,10 @@ func shouldSkipHTTPLog(path, route string, status int, latencyMs float64) bool {
 	return true
 }
 
-func isChatSSEPath(path, route string) bool {
+func isSSEPath(path, route string) bool {
-	return path == "/api/chats/events" || path == "/api/admin/chats/events" ||
+	return path == "/api/auth/events" || route == "/api/auth/events" ||
-		route == "/api/chats/events" || route == "/api/admin/chats/events"
+		path == "/api/chats/events" || route == "/api/chats/events" ||
+		path == "/api/admin/chats/events" || route == "/api/admin/chats/events"
 }
 
 func meaningfulAuthFailure(c *gin.Context) bool {

backend/internal/middleware/request_logger_test.go

@@ -19,6 +19,7 @@ func TestShouldSkipHTTPLog(t *testing.T) {
 		{name: "轮询 500 不跳过", path: "/api/wallet/balance", status: 500, latencyMs: 1, wantSkip: false},
 		{name: "限流请求不跳过", path: "/api/auth/sms", status: 429, latencyMs: 1, wantSkip: false},
 		{name: "慢请求不跳过", path: "/api/orders", status: 200, latencyMs: 500, wantSkip: false},
+		{name: "用户全局通知 SSE 长连接跳过", path: "/api/auth/events", route: "/api/auth/events", status: 200, latencyMs: 60_000, wantSkip: true},
 		{name: "用户 SSE 长连接跳过", path: "/api/chats/events", route: "/api/chats/events", status: 200, latencyMs: 60_000, wantSkip: true},
 		{name: "后台 SSE 长连接跳过", path: "/api/admin/chats/events", route: "/api/admin/chats/events", status: 200, latencyMs: 600_000, wantSkip: true},
 		{name: "SSE 服务端错误不跳过", path: "/api/admin/chats/events", route: "/api/admin/chats/events", status: 500, latencyMs: 600_000, wantSkip: false},

backend/internal/modules/chat/handler_error.go

@@ -1,6 +1,7 @@
 package chat
 
 import (
+	"context"
 	"errors"
 	"net/http"
 
@@ -10,6 +11,9 @@ import (
 )
 
 func writeChatError(c *gin.Context, err error) {
+	if errors.Is(err, context.Canceled) || errors.Is(c.Request.Context().Err(), context.Canceled) {
+		return
+	}
 	response.RecordError(c, err)
 	switch {
 	case errors.Is(err, ErrDependencyUnavailable):

backend/internal/modules/chat/support.go

@@ -229,6 +229,7 @@ func (r *Repository) listAdminConversations(ctx context.Context, principal Princ
 	var rows []conversationRow
 	offset := (page - 1) * pageSize
 	queryDB := r.adminConversationBase(ctx, principal, keyword).
+		Joins("LEFT JOIN chat_messages AS lm ON lm.id = c.last_message_id").
 		Select(`c.id, c.order_id, c.listing_id, c.type, c.support_scene, c.title, c.status, c.last_message_id,
 			c.last_message_preview, c.last_message_at, c.created_at, c.updated_at,
 			COALESCE(cp_me.role, 'admin') AS role,
@@ -302,7 +303,6 @@ func (r *Repository) adminConversationBase(ctx context.Context, principal Princi
 	db := r.db.WithContext(ctx).Table("chat_conversations AS c").
 		Joins("LEFT JOIN chat_participants AS cp_me ON cp_me.conversation_id = c.id AND cp_me.participant_type = ? AND cp_me.participant_id = ?", principal.Type, principal.ID).
 		Joins("LEFT JOIN chat_admin_conversation_states AS cas ON cas.conversation_id = c.id AND cas.admin_user_id = ?", principal.ID).
-		Joins("LEFT JOIN chat_messages AS lm ON lm.id = c.last_message_id").
 		Joins("LEFT JOIN rental_orders AS explicit_lo ON explicit_lo.id = c.order_id").
 		Joins("LEFT JOIN rental_listings AS l ON l.id = COALESCE(explicit_lo.listing_id, c.listing_id)")
 	if keyword != "" {

backend/pkg/response/response.go

@@ -1,6 +1,7 @@
 package response
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"net/http"
@@ -45,7 +46,7 @@ func Error(c *gin.Context, status int, code, message string) {
 
 // RecordError 保存原始错误，供统一请求日志记录服务端故障原因。
 func RecordError(c *gin.Context, err error) {
-	if c == nil || err == nil {
+	if c == nil || err == nil || errors.Is(err, context.Canceled) {
 		return
 	}
 	for _, item := range c.Errors {