what does `cf-cache-status: hit` header mean in workers, i thought you had to handle caching on your

what does

cf-cache-status: hit

cf-cache-status: hit

cf-cache-status: hit

cf-cache-status: hit header mean in workers, i thought you had to handle caching on your own using the cache runtime api?

MastonOP•11/22/23, 1:33 AM

i still get the log for the worker invocation if i enable realtime logs but the cf-cache-status header is "hit" so i dont really get it

MMaston what does `cf-cache-status: hit` header mean in workers, i thought you had to ha...

Chaika•11/22/23, 1:36 AM

You do. If you're fetching an origin behind CF you might be getting the cache status from the origin you're fetching

MMaston i still get the log for the worker invocation if i enable realtime logs but the ...

Chaika•11/22/23, 1:36 AM

Workers will always be invocated, they run in front of cache

MastonOP•11/22/23, 1:37 AM

interesting

MastonOP•11/22/23, 1:37 AM

im not fetching anything though

Unsmart•11/22/23, 1:39 AM

Whats your code then? Either doing a fetch or adding the cf-cache-status header yourself is the only ways you'd get a cache status header returned from a worker

MastonOP•11/22/23, 1:40 AM

https://github.com/mastondzn/cdn/blob/main/src/routes/images.ts this is everything that happens on this route note the header is x-cache-status not cf-cache-status

GitHub

cdn/src/routes/images.ts at main · mastondzn/cdn

Personal image/file uploader, built with Cloudflare Workers & R2. To be used mainly with ShareX. - mastondzn/cdn

MastonOP•11/22/23, 1:41 AM

this is a worker route

MastonOP•11/22/23, 1:41 AM

you can see the header right

Unsmart•11/22/23, 1:41 AM

That code is adding the header x-cache-status.

MastonOP•11/22/23, 1:41 AM

MastonOP•11/22/23, 1:42 AM

yeah i see that which is intended

MastonOP•11/22/23, 1:42 AM

but the cf-cache-status also appears

MastonOP•11/22/23, 1:42 AM

which is what i find odd

Unsmart•11/22/23, 1:43 AM

It might be automatically added by the cache api since you are using that

MMaston https://github.com/mastondzn/cdn/blob/main/src/routes/images.ts this is everythi...

Erisa•11/22/23, 1:45 AM

If you return a response directly from the cache api then its going to give cf-cache-status: HITcf-cache-status: HIT

MastonOP•11/22/23, 1:46 AM

ohh okay that makes sense

Erisa•11/22/23, 1:46 AM

But if theres nothing in there then youre not going to get a MISS because Workers doesn't know what you intended, so it will just have no header

Erisa•11/22/23, 1:47 AM

Adding your own header is smart if you want to be sure whats happening, then you can add your own extra states as well if you find a need to

Erisa•11/22/23, 1:47 AM

Since you cant modify cf-cf- headers

MastonOP•11/22/23, 1:48 AM

okay thanks that makes sense actually

MastonOP•11/22/23, 1:49 AM

and also i wanna say i was using wrangler before v3 and now this is way better dx with the local dev mode great work guys

EErisa Since you cant modify `cf-` headers

Chaika•11/22/23, 2:20 AM

minor but you can return your own cf-cache-status header from a worker, probably not a good idea, but I mean if you wanted to, could fake a miss

Erisa•11/22/23, 2:21 AM

Fun, okay then

Unsmart•11/22/23, 2:23 AM

Yeah workers can add cf-<anything> just the rules stuff cant. or at the very least a few of the cf-<things> I tried worked

Chaika•11/22/23, 2:24 AM

can't override cf-ray but lots of other things you can fake

MastonOP•11/22/23, 3:16 AM

this cache api is actually nice you can upload stuff and instantly insert in your cache aswell so even the first request can be cached, very cool

Ottomated•11/22/23, 4:16 AM

Does anyone have recommendations for a rate limiting library backed by D1 or KV?

Unsmart•11/22/23, 4:21 AM

KV shouldnt really be used for rate limiting as theres a limit to writes on the same key to 1 per second. Not aware of any rate limiting libraries with D1 though, only rate limiter I am really aware of is this repo with the code for making one with durable objects: https://github.com/honzabit/durable-limiter

Unsmart•11/22/23, 4:23 AM

Of course would highly recommend using cloudflare waf rate limiting rules if you can (they are free and unmetered now they used to be paid)

quambo•11/23/23, 12:56 PM

Quick question around durable objects and setAlarm. Since Date.now() will only return the time of the last IO, the below example may set the alarm to a past time. Is this correct? Is the alarm still guaranteed to execute in that case?

  async alarm() {
    // Perform something that could take up to 15 seconds
    await doSomething();
    // Schedule task for the next second
    this.state.storage.setAlarm(Date.now() + parseDuration('1s'));
  }

  async alarm() {
    // Perform something that could take up to 15 seconds
    await doSomething();
    // Schedule task for the next second
    this.state.storage.setAlarm(Date.now() + parseDuration('1s'));
  }

Qquambo Quick question around durable objects and setAlarm. Since Date.now() will only r...

DaniFoldi•11/23/23, 1:02 PM

Your observation is correct, fortunately the documentation says that setting an alarm for a past date triggers immediately

DaniFoldi•11/23/23, 1:08 PM

Aha, found the docs: https://developers.cloudflare.com/durable-objects/api/transactional-storage-api/

If setAlarm() is called with a time equal to or before Date.now(), the alarm will be scheduled for asynchronous execution in the immediate future. If the alarm handler is currently executing in this case, it will not be canceled. Alarms can be set to millisecond granularity and will usually execute within a few milliseconds after the set time, but can be delayed by up to a minute due to maintenance or failures while failover takes place.

Transactional Storage · Cloudflare Durable Objects docs

The Transactional Storage API allows you to achieve consistent key-value storage.