How Kinsta Uses Cloudflare Workers To Improve Cache Hit Rates by 56%

Paulo Paracatu

Since we always read the domain’s Workers KV data, we realized we could route requests and customize the cache key, appending things like the domain’s ID and features that could affect the asset, like Polish. Today, our cache key is heavily customized to quickly reflect every client’s change in our panel or API. By modifying the cache key using Workers KV’s data, nobody needs to worry about clearing the cache anymore. As soon as Workers KV propagates the changes, the cache key also changes, and we request and cache a fresh asset.

However, unlike many applications, we can’t cache Workers KV for extended periods. Kinsta’s customers are constantly trying new features, changing Polish and Auto Minify settings, sometimes excluding pages or extensions from being cached, and they want to see their changes in production as soon as possible.

Of course, you need to check the URL for existing parameters to determine which connector to use — ? or & — and ensure you are using a unique identifier.

const handleKVCache = async (event, myCustomDomain) => {
  // Try to get KV from cache first
  const cache = caches.default;
  let site_data = await cache.match( `https://${myCustomDomain}/some-string-ID-kv-data/` );

  // Valid KV cache match
  if (site_data && site_data.status === 200) {
    // ... modify your cached data if necessary, then return it
    return site_data;
  }

  // Invalid cache (expired, miss, etc), get data from KV namespace
  site_data = await KV_NAMESPACE.get(myCustomDomain.toLowerCase());
  
  // Cache valid KV responses with Cache API
  if (site_data) {
    let kvResponse = new Response(JSON.stringify(site_data), {status: 200});
    kvResponse.headers.set("Cache-Control", "public, s-maxage=30");
    event.waitUntil(cache.put(`https://${myCustomDomain}/some-string-ID-kv-data/`, kvResponse));
  }
  
  return site_data;
};

It’s pretty simple to implement your own Workers KV caching logic. For example:

Get all your applications, databases, and WordPress sites online and under one roof. Our feature-packed, high-performance cloud platform includes:

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• Global audience reach with up to 35 data centers and 260 PoPs worldwide

Workers KV operations are affordable, but the numbers can pile up when you trigger billions of reading operations daily.

That’s when we decided to microcache our Workers KV data — caching dynamic or constantly-changed content for a very short period of time, usually less than 60 seconds.

// Assign KV values to variables
const { customBackend } = kvdata.kinstaConf;

// Override the backend
cf.resolveOverride = customBackend;

Paulo is a seasoned DevOps Engineer at Kinsta with a solid web hosting and optimization background. Equipped with Bash and JavaScript expertise, he uses Cloudflare Workers to continually improve user experiences in hosting.