(1)Caching is a last resort
招数1：
缓存是最后的手段
Projects that use multiple levels of cache often demonstrate a misunderstanding of why caching is required in the first place.
项目中使用多重缓存经常会表现会产生误会，为什么缓存是第一步必须的。
Caching is not synonymous with performance. Your code should already be efficient. Caching should only be used as a last resort, after you’ve made all possible (and sensible) code optimizations.
缓存不是性能的同义词。你的代码应该已经很高效。缓存仅仅用于你尝试过所有可能的（你能想到的）代码优化后的最后手段。