@Override
  public void init() {
    ShutdownHookManager.addShutdownHook(() -> save());
    initSavePath();
    if (llapIo == null) {
      llapIo = LlapProxy.getIo();
    }
  }
Simple cache hydration strategy which saves the content info of the cache to a file on the local filesystem on
shutdown, and loads it when the daemon starts.
llap-server/src/java/org/apache/hadoop/hive/llap/cache/BasicLlapCacheHydration.java