Re replacement policy - that&#x27;s why I mentioned that the file can be changed. You&#x27;ll need an mtime&#x2F;inode&#x2F;time check on each request &#x2F; periodically.<p>Cache can miss? I don&#x27;t think that&#x27;s required. It can miss in a general sense, as in it needs to be lazy loaded. But I&#x27;d still call it caching if you&#x27;re getting a single value. For example, you can still cache whole front page with server-side push into the cache. You also can&#x27;t miss in that case.<p>But yeah, that&#x27;s just details. Cache&#x2F;memory structure is a rather vague separation.