private boolean isBacklog(long now, OneMerge merge) {
    double mergeMB = bytesToMB(merge.estimatedMergeBytes);
    for (MergeThread mergeThread : mergeThreads) {
      long mergeStartNS = mergeThread.merge.mergeStartNS;
      if (mergeThread.isAlive() && mergeThread.merge != merge &&
          mergeStartNS != -1 &&
          mergeThread.merge.estimatedMergeBytes >= MIN_BIG_MERGE_MB*1024*1024 &&
          nsToSec(now-mergeStartNS) > 3.0) {
        double otherMergeMB = bytesToMB(mergeThread.merge.estimatedMergeBytes);
        double ratio = otherMergeMB / mergeMB;
        if (ratio > 0.3 && ratio < 3.0) {
          return true;
        }
      }
    }

    return false;
  }