https://semikolan.me/tags/caching/ Recent content in caching on semikolan Hugo en Mon, 27 Jul 2026 21:19:11 +0530 https://semikolan.me/blog/cache-invalidation-mostly-naming/ Tue, 12 May 2026 00:00:00 +0000 https://semikolan.me/blog/cache-invalidation-mostly-naming/ <p>The joke is that there are two hard problems in computer science: cache invalidation and naming things. I&rsquo;ve come to think they&rsquo;re the same problem wearing two hats.</p> <h2 id="what-a-key-really-is">What a key really is <a class="anchor" href="#what-a-key-really-is" aria-label="Link to this section">#</a></h2> <p>A cache key is a name for a claim: &ldquo;the answer to <em>this question</em> is <em>that value</em>.&rdquo; Invalidation is just noticing the claim stopped being true. The reason invalidation is hard is almost never the eviction mechanics — it&rsquo;s that the key doesn&rsquo;t actually name the claim.</p>