@Override public Thread newThread(Runnable r) {
          Thread t = Executors.defaultThreadFactory().newThread(r);
          t.setName("CachedStore-CacheUpdateService: Thread-" + t.getId());
          t.setDaemon(true);
          return t;
        }
This starts a background thread, which initially populates the SharedCache and later
periodically gets updates from the metastore db

@param conf
@param runOnlyOnce
@param shouldRunPrewarm
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/cache/CachedStore.java