Cloudflare Developers•16mo ago

Forgive me, what is a DO?

EEXE KL Forgive me, what is a DO?

Hard@Work•9/19/24, 1:42 PM

https://developers.cloudflare.com/durable-objects/#_top

Cloudflare Docs

Overview | Cloudflare Durable Objects docs

Durable Objects provide a powerful API for coordinating multiple clients or users, each with private, transactional and strongly consistent storage attached.

HHard@Work https://developers.cloudflare.com/durable-objects/#_top

EXE KLOP•9/19/24, 1:44 PM

Ah okay, so this is available through the transactional storage api?

Hard@Work•9/19/24, 1:44 PM

Or well, each DO has a separate KV Store

HHard@Work Or well, each DO has a separate KV Store

EXE KLOP•9/19/24, 1:46 PM

Thanks, I'll take a proper read through it.

EEXE KL Thanks, I'll take a proper read through it.

thomasgauvin•9/19/24, 8:13 PM

This seems like an optimization for an extremely unlikely use case. How many keys do you plan on storing and is it anywhere near risking hash collision?

You could also reduce probably by making a read first, and writing it if it doesn't exist. It won't deterministically guarantee that you aren't overwriting, because it may have been written/propagated to KV since the read, but it wouldn't hurt in reducing chances of collision

If you need stronger unique guarantees, DO/D1 may be better options

Tthomasgauvin This seems like an optimization for an extremely unlikely use case. How many key...

EXE KLOP•9/19/24, 8:35 PM

My plan is to reuse this authentication and session system whenever I can when making Sveltekit projects so I wanted to make something robust enough to handle a large number of users authenticating themselves frequently. I've considered reading before the writing but as you mentioned it only reduces the chances on top of an extra network call. D1 was the only real solution for me before learning about DO.

EXE KLOP•9/19/24, 8:44 PM

As for the use cases. I probably may never generate enough magic tokens to increase the odds of a duplication within a period of time as the size of the tokens is 64 chars generated by the crypto module. I think I just wanted a solution to a hypothetical problem.:NotLikeThis:

EEXE KL My plan is to reuse this authentication and session system whenever I can when m...

hfcRed•9/20/24, 11:09 AM

Make a separate KV for every project and you should be fine

hfcRed•9/20/24, 11:10 AM

If you really want to avoid collision at all cost, then you can append a unix timestamp to the token

hfcRed•9/20/24, 11:11 AM

If you manage to generate two identical 64 char tokens within a single second you would probably be the luckiest human to have ever existed. Heck, even getting a single collision at all would make you the luckiest person of all time

hfcRed•9/20/24, 11:12 AM

You could also generate a UUID7 which has a granularity of up to 50 nanoseconds

EEXE KL My plan is to reuse this authentication and session system whenever I can when m...

thomasgauvin•9/20/24, 12:27 PM

You should probably store your information in D1, then optimize with KV (ie once a user logs in, check hash against db hashed, but then store tokens in kv and use that for auth validation)

Anton•9/20/24, 4:04 PM

Why key-value data storage is so expensive comparing to other resources?

KV read price - $0.50/million
Durable objects (that sounds a lot more complex, "permanent" and expensive) - $0.15/million
D1 database - $0.001 / million rows reads

Why everything else, where I can store some data is cheaper? Isn't kv - a cheap, temporary, cache storage?

AAnton Why key-value data storage is so expensive comparing to other resources? KV rea...

Matt Silverlock•9/20/24, 4:13 PM

KV isn't temporary - KV storage is persistent: https://developers.cloudflare.com/kv/

Cloudflare Docs

Cloudflare Workers KV | Cloudflare Workers KV

Workers KV is a data storage that allows you to store and retrieve data globally. With Workers KV, you can build dynamic and performant APIs and websites that support high read volumes with low latency.

AAnton Why key-value data storage is so expensive comparing to other resources? KV rea...

thomasgauvin•9/20/24, 4:24 PM

And to add on to Matt's response, each key-value pair in KV can handle a much higher throughput than individual rows in D1

Anton•9/20/24, 4:31 PM

Hmm, ok. Is KV the best tool to store and read some cache data? Like I have a complex worker function. During its work, I have to hit several 3rd party API. And I don't want to call them on every worker execution. I want to temporary cache data. On regular server I would use redis or a simple in-memory cache. What about worker? What should I use here? KV?

AAnton Hmm, ok. Is KV the best tool to store and read some cache data? Like I have a co...

thomasgauvin•9/20/24, 4:39 PM

Yes, KV is the tool for this. there's cache api https://developers.cloudflare.com/workers/runtime-apis/cache/ but that is definitely an optimization and might get evicted from cache

AAnton Hmm, ok. Is KV the best tool to store and read some cache data? Like I have a co...

JacobMGEvans•9/21/24, 10:26 PM

Definitely something you can do, I use KV to store Tailwind off the CDN (for funsies), I try weird uses of Cloudflare products in this project all the time just to see if I can and if there is other novel things you can do https://github.com/JacobMGEvans/JacobMGEvans/blob/main/src/index.ts

JacobMGEvans•9/21/24, 10:28 PM

Additionally you can use the Worker Cron to run occasionally and purge anything thats older than a certain age you give them, since you mentioned temporary

Ashish Rawat•9/23/24, 5:50 PM

I think KV is good for storing permission level data on top of D1. Like checking for permissions of a user on each api call before accessing D1 or other db.

TigersWay•9/25/24, 7:41 AM

Still receiving the message "Daily request limit exceeded for Cloudflare Workers" for a "1000 put operations" which is in fact of 226 right now!
More than a week has passed, shouldn't we have more information?

Bọc Link VN•9/25/24, 10:35 AM

Hello every one ! Have anyone know how to rename the KV Namespace?

Bọc Link VN•9/25/24, 10:35 AM

I remember that it could be renamed in the past but now it seems not to work anymore

TTigersWay Still receiving the message "Daily request limit exceeded for Cloudflare Workers...

thomasgauvin•9/25/24, 1:53 PM

Thanks for bringing it up again. This is our top priority fix at the moment. A query that is being made to alert on free quotas is misreporting quotas, so we’re fixing that. I will keep this message thread updated. Note that the query resets every day so you may not encounter this all the time

JJacobMGEvans Additionally you can use the Worker Cron to run occasionally and purge anything ...

thipperz•9/25/24, 11:59 PM

That's interesting, how do you check the current age of a KV key? I would like to set a high cacheTtl for a key while also being able to show a 'refresh' button if the current value is cached but also 3 days old for example

Tthomasgauvin Thanks for bringing it up again. This is our top priority fix at the moment. A q...

TigersWay•9/26/24, 2:13 AM

I somehow understand it needs time to fix it, but shouldn't WE have a test period for this kind of things?

Tthipperz That's interesting, how do you check the current age of a KV key? I would like t...

JacobMGEvans•9/26/24, 2:21 AM

I'd have to look at how I've done it before but my knee jerk (from my phone) reaction without looking is probably timestamp in the Metadata, maybe something like this

async function setKVValueWithTimestamp(key, value, cacheTtl) {
  const timestamp = Date.now();
  const data = JSON.stringify({ value, timestamp });
  await KV_NAMESPACE.put(key, data, { expirationTtl: cacheTtl });
}

async function setKVValueWithTimestamp(key, value, cacheTtl) {
  const timestamp = Date.now();
  const data = JSON.stringify({ value, timestamp });
  await KV_NAMESPACE.put(key, data, { expirationTtl: cacheTtl });
}

JJacobMGEvans I'd have to look at how I've done it before but my knee jerk (from my phone) rea...

thipperz•9/26/24, 3:28 AM

Ahh, sure! Thank you! That will do it

Matt Silverlock•9/26/24, 3:11 PM

In case you missed it — here's the details on the latest Workers KV performance improvements that just shipped! https://blog.cloudflare.com/faster-workers-kv/ @Workers KV

The Cloudflare Blog

We made Workers KV up to 3x faster — here’s the data

Today, we’re announcing up to 3x faster KV hot reads, with all KV operations faster by up to 20ms. And we want to pull back the curtain and show you how we did it.

AZipr•9/26/24, 3:16 PM

Wow!

Thats a massive gain!

Devon•9/26/24, 3:16 PM

that's huge! very nice!

Devon•9/26/24, 3:16 PM

Thank you!

MMatt Silverlock In case you missed it — here's the details on the latest Workers KV performance ...

thomasgauvin•9/26/24, 5:11 PM

We're super excited for this ship, and we're going to continue to make KV super fast for your data globally. The details of how we did it are all in the blog, but the graphs really show the impact

Brian Ball•9/27/24, 6:51 PM

In the kv docs /getting-started

I can't get this command to work:

npx wrangler kv key put --binding=<BINDING_NAME> "<KEY>" "<VALUE>"

just trying to follow the kv-tutorial

I used kv_binding_name - trying to follow the docs.

Though the docs say: name it BINDING_NAME - the very next step shows a create command with kv_binding_name

✘ [ERROR] A namespace with binding name "kv_binding_name" was not found in the configured "kv_namespaces".

✘ [ERROR] A namespace with binding name "kv-tutorial-kv_binding_name" was not found in the configured "kv_namespaces".

Brian Ball•9/27/24, 6:52 PM

It does work with the ID - but, I'm just reporting broken documentation continuity.

JamieD132•9/28/24, 7:01 AM

help I am trying to import kv to my javascript worker with

import { KVNameSpace } from '@cloudflare/kv-name-space'

import { KVNameSpace } from '@cloudflare/kv-name-space'

but it doesn;t work

JJamieD132 help I am trying to import kv to my javascript worker with `import { KVNameSpace...

tadhglewis•9/28/24, 8:38 AM

it doesn;t work

@JamieD132 What is the error you're getting and what do you expect to get?

tadhglewis•9/28/24, 8:39 AM

The package mentioned doesn't even exist

https://www.npmjs.com/package/@cloudflare/kv-name-space

kindaraffy•9/28/24, 3:27 PM

Hi guys! The documentation is a little murky on this one, how do I specify the expiration on the KV PUT REST body? https://developers.cloudflare.com/api/operations/workers-kv-namespace-write-key-value-pair-with-metadata

Cloudflare API Documentation

Interact with Cloudflare's products and services via the Cloudflare API

Kkindaraffy Hi guys! The documentation is a little murky on this one, how do I specify the e...

Marcus•9/28/24, 7:57 PM

Ooh yeah they should have an example body there, for sure. I assume it's the same as the

wrangler kv bulk put

wrangler kv bulk put

entries: https://developers.cloudflare.com/workers/wrangler/commands/#kv-bulk-put

JJamieD132 help I am trying to import kv to my javascript worker with `import { KVNameSpace...

Marcus•9/28/24, 8:02 PM

was that a suggestion from an AI tool? that's my best guess :D anyway, follow https://developers.cloudflare.com/kv/get-started/#3-bind-your-worker-to-your-kv-namespace and https://developers.cloudflare.com/kv/get-started/#5-access-your-kv-namespace-from-your-worker to use a KV namespace with a worker

Kkindaraffy Hi guys! The documentation is a little murky on this one, how do I specify the e...

thomasgauvin•9/30/24, 1:47 PM

Thanks for flagging! let me verify

thomasgauvin•9/30/24, 2:27 PM

@kindaraffy yes, expiration is supported in the REST API, we'll be fix that in docs

You can specify expiration or expirationTtl as a query param

So I can tell the users: https://api.cloudflare.com/client/v4
/accounts/{account_id}/storage/kv/namespaces/{namespace_id}/values/{key_name}?expiration=<secondsSinceEpoch>

or https://api.cloudflare.com/client/v4
/accounts/{account_id}/storage/kv/namespaces/{namespace_id}/values/{key_name}?expirationTtl=<secondsFromNow>

kindaraffy•9/30/24, 2:28 PM

Thank you.

carlos-alberto•10/1/24, 3:22 PM

Hey! Are there documented (or undocumented) rate limits on number of writes to different KV keys from a worker (on the paid plan)? We are seeing 429s when we try to write a few thousand keys within a few seconds.

thomasgauvin•10/1/24, 3:29 PM

KV has 1 write per second per key limit from the binding https://developers.cloudflare.com/kv/platform/limits/ and the APIs have global rate limits https://developers.cloudflare.com/fundamentals/api/reference/limits/#:~:text=The%20global%20rate%20limit%20for,receiving%20a%20HTTP%20429%20response.

carlos-alberto•10/1/24, 3:31 PM

Do the api rate limits apply to calls made from a worker binding?

carlos-alberto•10/1/24, 3:32 PM

We are writing to different keys, so the 1 per second should not apply

thomasgauvin•10/1/24, 3:41 PM

DM'd

ItsWendell•10/1/24, 4:41 PM

Related to the new upcoming cache purging changes, couldn't these also apply to KV?

https://blog.cloudflare.com/instant-purge/

Is it generally possible to purge a specific KV key? I think if a KV value is locally cached, and you update this it could in theory especially with the new purging system 'instantly' purge all regional KV caches right? Think this could bring quite some benefits to keep KV reads latency.

E.g. I need super quick access to a 'configuration' stored in KV, this 'configuration' is updated at most a couple of times a day. If we can keep this in the cache until this value is updated or deleted, it would speed up calls to KV a lot. Currently it's documented that KV updates do not purge KV caches, in this case it would be great if it did!

async function setKVValueWithTimestamp(key, value, cacheTtl) { const timestamp = Date.now(); const data = JSON.stringify({ value, timestamp }); await KV_NAMESPACE.put(key, data, { expirationTtl: cacheTtl }); }

Forgive me, what is a DO?

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