chore: auth check

Author: hash-data

drivers/mongodb/internal/backfill.go

@@ -268,7 +268,8 @@ func (m *Mongo) splitChunks(ctx context.Context, collection *mongo.Collection, s
 		return timestampStrategy()
 	default:
 		chunks, err := splitVectorStrategy()
-		if err != nil {
+		// check if authorization error occurs
+		if err != nil && strings.Contains(err.Error(), "not authorized") {
 			logger.Warnf("failed to get chunks via split vector strategy: %s", err)
 			return bucketAutoStrategy()
 		}