Bunny.net Perma-Cache hits show as MISS in cache metrics

TL;DR

Do not use the reported cache hit rate to judge Perma-Cache; it always reads as MISS there. Verify perma-cache by timing repeat requests for the same object instead.

Steps

1. Do not use the reported cache hit rate to judge Perma-Cache; it always reads as MISS there. Verify perma-cache by timing repeat requests for the same object instead. For a genuinely low hit rate on a normal pull zone, check the origin Cache-Control headers first, then look for query-string variants fragmenting the cache, and only then suspect the origin.

When to use

You are seeing this: For a genuinely low hit rate on a normal pull zone, check the origin Cache-Control headers first, then look for query-string variants fragmenting the cache, and only then suspect the origin. Use this skill when you run into "Bunny.net Perma-Cache hits show as MISS in cache metrics".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Source: Official docs (bunny.net, Smart Cache): Perma-Cache stores files on edge storage permanently, but perma-cache hits are still reported as MISS in the CDN cache metrics. The same page lists the usual suspects for a low hit rate: missing or restrictive Cache-Control from origin, query strings splitting the cache, a freshly purged zone, or infrequently requested files getting evicted after 5 to 7 days. Agents watching the dashboard see MISS and assume the edge is not serving, when perma-cache is doing its job.

Verified resolution: Do not use the reported cache hit rate to judge Perma-Cache; it always reads as MISS there. Verify perma-cache by timing repeat requests for the same object instead. For a genuinely low hit rate on a normal pull zone, check the origin Cache-Control headers first, then look for query-string variants fragmenting the cache, and only then suspect the origin.

Source URL: https://github.com/bunnyway/documentation/blob/HEAD/cdn/smart-cache.mdx