private int bucketSizesAboveThresholdCount(float minFactor) {
    if (!isCacheInitialized("BucketCache::bucketSizesAboveThresholdCount")) {
      return 0;
    }

    BucketAllocator.IndexStatistics[] stats = bucketAllocator.getIndexStatistics();
    int fullCount = 0;
    for (int i = 0; i < stats.length; i++) {
      long freeGoal = (long) Math.floor(stats[i].totalCount() * (1 - minFactor));
      freeGoal = Math.max(freeGoal, 1);
      if (stats[i].freeCount() < freeGoal) {
        fullCount++;
      }
    }
    return fullCount;
  }
Return the count of bucketSizeinfos still need free space
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java