private boolean isHighLevelCacheEnable() {
		if (highLevelCache == null) {
			return false;
		}

		// 如果上一次连接不成功，则判断是否超过重连时间
		boolean reconnect = false;
		if (!highLevelCacheReachable) {
			long interval = System.currentTimeMillis() - lastUnreachableTime;
			if (interval > reconnectTime) {
				reconnect = true;
			}
		}

		return (highLevelCacheReachable || reconnect);
	}