public void printCacheStats() {
    double hitRate = ambryCache.stats().requestCount() == 0 ? 0 : ((100f * ambryCache.stats().hitCount())/ambryCache.stats().requestCount());
    double evictionRate = ambryCache.stats().requestCount() == 0 ? 0 : ((100f * ambryCache.stats().evictionCount())/ambryCache.stats().requestCount());
    long numEntries = ambryCache.estimatedSize();
    logger.info("[{}] hit rate = {}, eviction rate = {}, size = {}", cacheId, hitRate, evictionRate, numEntries);
  }
Deletes a value associated with a key
@param key Object for indexing the cache
@return True, if delete succeeded. Else, false.
ambry-commons/src/main/java/com/github/ambry/commons/AmbryCache.java