cdc,regionspan(ticdc): more logs about eventfeed retry rate limit (pi…

…ngcap#4008)

cdc/kv/client.go

@@ -518,6 +518,8 @@ func (s *eventFeedSession) eventFeed(ctx context.Context, ts uint64) error {
 		}
 	})
 
+	tableID, tableName := util.TableIDFromCtx(ctx)
+	cfID := util.ChangefeedIDFromCtx(ctx)
 	g.Go(func() error {
 		checkRateLimitInterval := 50 * time.Millisecond
 		timer := time.NewTimer(checkRateLimitInterval)
@@ -533,7 +535,13 @@ func (s *eventFeedSession) eventFeed(ctx context.Context, ts uint64) error {
 				s.errChSizeGauge.Dec()
 				allowed := s.checkRateLimit(errInfo.singleRegionInfo.verID.GetID())
 				if !allowed {
-					// rate limit triggers, add the error info to the rate limit queue
+					// rate limit triggers, add the error info to the rate limit queue.
+					log.Info("EventFeed retry rate limited",
+						zap.Uint64("regionID", errInfo.singleRegionInfo.verID.GetID()),
+						zap.Uint64("ts", errInfo.singleRegionInfo.ts),
+						zap.String("changefeed", cfID), zap.Stringer("span", errInfo.span),
+						zap.Int64("tableID", tableID), zap.String("tableName", tableName),
+						zap.String("addr", errInfo.singleRegionInfo.rpcCtx.Addr))
 					s.rateLimitQueue = append(s.rateLimitQueue, errInfo)
 				} else {
 					err := s.handleError(ctx, errInfo)
@@ -980,15 +988,11 @@ func (s *eventFeedSession) handleRateLimit(ctx context.Context) {
 }
 
 // checkRateLimit checks whether a region can be reconnected based on its rate limiter
-func (s *eventFeedSession) checkRateLimit(regionID uint64) (allowed bool) {
+func (s *eventFeedSession) checkRateLimit(regionID uint64) bool {
 	limiter := s.client.getRegionLimiter(regionID)
 	// use Limiter.Allow here since if exceed the rate limit, we skip this region
 	// and try it later.
-	allowed = limiter.Allow()
-	if !allowed {
-		log.Info("EventFeed retry rate limited", zap.Uint64("regionID", regionID))
-	}
-	return
+	return limiter.Allow()
 }
 
 // handleError handles error returned by a region. If some new EventFeed connection should be established, the region