feat: reduce MongoDB buffer logging verbosity and disable processing rate calculation

Author: ZhangYongguang5467

pkg/api/monitor_handler.go

@@ -464,7 +464,7 @@ ORDER BY task_id, collection_name
 	if totalActiveStreams > 0 && totalExecuted > 0 {
 		// Simple calculation: assume data represents recent activity
 		// For more accurate rate, we would need time-based windows
-		processingRate = fmt.Sprintf("~%d/min", totalExecuted)
+		// processingRate = fmt.Sprintf("~%d/min", totalExecuted)
 	}
 
 	// Prepare response

pkg/syncer/mongodb/mongodb.go

@@ -718,13 +718,13 @@ func (s *MongoDBSyncer) watchChanges(ctx context.Context, sourceColl, targetColl
 
 					if buffSize >= batchSize {
 						if s.bufferEnabled {
-							s.logger.Infof("[MongoDB] buffer reached %d => storing to persistent buffer => %s.%s", batchSize, sourceDB, collectionName)
+							s.logger.Debugf("[MongoDB] buffer reached %d => storing to persistent buffer => %s.%s", batchSize, sourceDB, collectionName)
 							tokenMutex.RLock()
 							currentToken := latestToken
 							tokenMutex.RUnlock()
 							s.storeToBuffer(ctx, &buffer, sourceDB, collectionName, currentToken)
 						} else {
-							s.logger.Infof("[MongoDB] buffer reached %d => flush now => %s.%s", batchSize, sourceDB, collectionName)
+							s.logger.Debugf("[MongoDB] buffer reached %d => flush now => %s.%s", batchSize, sourceDB, collectionName)
 							tokenMutex.RLock()
 							currentToken := latestToken
 							tokenMutex.RUnlock()