public long getIOHitsPerSecond() {
    long now = EnvironmentEdgeManager.currentTime();
    long took = (now - lastLogTime) / 1000;
    lastLogTime = now;
    return took == 0 ? 0 : ioHitCount.sum() / took;
  }
Class that implements cache metrics for bucket cache.
hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCacheStats.java