Hi, I need some clarifications regarding DO billing: - [1] "Each Durable Object stays alive as long

Hi, I need some clarifications regarding DO billing:

[1] "Each Durable Object stays alive as long as requests are being processed, and remains alive for several seconds after being idle before hibernating"
[2] "Once your Object finishes responding to all requests, it will stop incurring duration charges"
So assume if for my use-case, I only use RPC to query/migrate sqlite, does this mean I will get duration charges only for the RPC session, which is probably a few milliseconds, or also for the whole "alive duration" which includes "several seconds after being idle before hibernating"?

[1] https://developers.cloudflare.com/durable-objects/what-are-durable-objects/#durable-objects-highlights
[2] https://developers.cloudflare.com/durable-objects/platform/pricing

Eelunesarrow Hi, I need some clarifications regarding DO billing: - [1] "Each Durable Object ...

1984 Ford Laser•2/3/25, 9:49 AM

Only the few milliseconds is billed, the few seconds of aliveness is mostly a runtime consideration and doesn't really matter for most development architectures, unless you need to persist the DO state specifically between calls

jed•2/3/25, 12:22 PM

hey all, i've got a setup in which a worker serves an app (html / js) and an api (websocket). to prevent app deployment from resetting connections, i've got the app on a service binding. my question is this: what's the best way for the api to report app deployment events in realtime? if outgoing DO websockets could hibernate, i'd have the app server host a websocket that just reported its version on connection, but given that's not possible, what's the easiest way to achieve this? i'd rather not use the DO list API or open two websockets from the browser... would long polling from DO to app server be viable? i'd like the events to be as realtime as possible to allow instant reloads. thanks!

Ggeg @quan @1984 Ford Laser It was definitely because I didn't send pings when not se...

quan•2/3/25, 2:07 PM

oh, how long do you do the interval now? i am trying a timeout of 15 seconds to send a ws.send("") from react client to the websocket server, then server response back

i had more success with SSE before, but not sure why on ws it keeps disconnecting me from the server after around 30seconds

Qquan oh, how long do you do the interval now? i am trying a timeout of 15 seconds to ...

geg•2/3/25, 2:15 PM

If your client is in the browser this shouldn't be necessary. I was talking about websocket pings (not messages).

Rahul gangotri•2/3/25, 3:22 PM

I am running a browser rendering that goto a url and fetch text content from the page inside a durable object

i also reuse sessions and pick any free random session to decrease the load time

still many url's are taking upto 15 sec. i am waiting until networkidle0

can someone please help me optimize this?

Rahul gangotri•2/3/25, 3:23 PM

when i used to run playwright on my own machine and scrape using that, it takes 2-3 sec for page to load

Rahul gangotri•2/3/25, 3:23 PM

same page here is taking 10-15 sec.

DDiamondDragon I'd also be curious to learn more about how people are building apps where you h...

James•2/3/25, 4:06 PM

I read aggregate data a lot more than write transactional, so I usually aggregate to central DB on writes to source tables (in DO) in real time.

For example, rather than query all DOs for some cross DO action like, 'last updated TS', I'll sync up a central log of all 'last updated TS' mapped to the DO.

Llambrospetrou First of all `await setAnotherAlarm()` does not set a new alarm, it overrides th...

lambrospetrou•2/3/25, 7:00 PM

Circling back to this, if in your alarm handler you set a new alarm, and your handler throws AFTER, there won't be a retry since a new alarm has been successfully set.

Best practice for alarms, always set the new alarm AFTER your processing is done, so that exceptions are retried properly, if you need the retries.

RRahul gangotri I am running a browser rendering that goto a url and fetch text content from the...

Rahul gangotri•2/3/25, 10:56 PM

Anyone help on this?

Nnil wrote a util to help with maximum 6 concurrent network requests... has anyone do...

lambrospetrou•2/3/25, 11:53 PM

I have a similar, but simpler approach in my DO helper package: https://github.com/lambrospetrou/durable-utils/blob/main/src/do-sharding.ts#L154-L187

That's a bit specific to the specific class logic, but it does the same thing as yours, limit processing among N things with a given concurrency. Check it out in case it simplifies anything on your side.
I didn't know about the

p-limit

p-limit

package you used though, so maybe that's enough already.

1984 Ford Laser•2/4/25, 5:45 AM

I wish that stubs would automatically proxy calls to things like

get()

get()

put()

put()

to be able to access instance storage from another worker/DO directly

Llambrospetrou I have a similar, but simpler approach in my DO helper package: https://github.c...

森

森@VerseLink (RW)•2/4/25, 6:57 AM

@nil p-limit should work, it's pretty much the same logic, it does what you want, I've used it before to queue up subrequests

Exception•2/4/25, 8:04 AM

I want to do some analysis on the values stored in a DO object. I current do, one DO per user session uniquely identified by an id. Is it wise to create another DO that keeps a list of all created sessions/DO and have it retrieve the data for all sessions? I'm also thinking I can forward the session data to a central DO that holds the data for all sessions. Or is there a better approach?

Nnil @lambrospetrou Does using a DO get around the simultaneous open connections of 6...

lambrospetrou•2/4/25, 9:37 AM

Probably, but you do pay all those DOs being active, so it depends on your use-case if it's better.

11984 Ford Laser I wish that stubs would automatically proxy calls to things like `get()`/`put()`...

lambrospetrou•2/4/25, 9:39 AM

You mean instead of adding the 2 lines yourself, or is there something else in this?

SnowBall•2/4/25, 10:07 AM

SnowBall•2/4/25, 10:08 AM

有中国的哥们吗

Llambrospetrou You mean instead of adding the 2 lines yourself, or is there something else in t...

1984 Ford Laser•2/4/25, 10:22 AM

I mean when you put it like that...

Nnil wrote a util to help with maximum 6 concurrent network requests... has anyone do...

sathoro•2/4/25, 11:05 AM

why do you need to do this? it will queue the requests automatically

Nnil Might have been a wrangler dev issue but I ran into a resource limit: "Response ...

Isaac McFadyen•2/4/25, 7:16 PM

Yeah I've gotten this as well in production

iLearn•2/4/25, 8:43 PM

Are the options "options: { expiration?: number, expirationTtl?: number, metadata?: object }" available for Workers-KV available for DO-KV storage ?

Checked the link "https://developers.cloudflare.com/durable-objects/api/storage-api/#supported-options-1" and could not find the aforesaid options and hence wanted to confirm.

Cloudflare Docs

Durable Object Storage · Cloudflare Durable Objects docs

The Durable Object Storage API allows Durable Objects to access transactional and strongly consistent storage. A Durable Object's attached storage is private to its unique instance and cannot be accessed by other objects.

IiLearn Are the options "options: { expiration?: number, expirationTtl?: number, metadat...

1984 Ford Laser•2/4/25, 8:47 PM

Nah I don't think so, Workers KV and DO KV are technically different. Like Workers KV will show a

list()

list()

as the keys, whereas DO KV returns the k:v pairs

11984 Ford Laser Nah I don't think so, Workers KV and DO KV are technically different. Like Worke...

iLearn•2/4/25, 8:50 PM

Thanks for sharing your understanding.

iLearn•2/4/25, 8:55 PM

Since, expirationTtl (option in Workers-KV) is not an option for DO-KV, what are the ways to achieve the same functionality where the Key need to be deleted after, say 10 minutes ?

iLearn•2/4/25, 8:56 PM

Since, expirationTtl (option in Workers-KV) is not an option for DO-KV, what are the ways to achieve the same functionality where the Key need to be deleted after, say 10 minutes ?

Original message was deleted

iLearn•2/4/25, 9:03 PM

Thanks for sharing your understanding.
now i am in catch-22 situation .. wanted to use DO-KV to use ready-made infra for race-condition-avoidance and all goodies of Workers-KV .. but, now with the missing option of expirationTtl .. considering to go back to Workers-KV ..

choice is either manage race-condition or manage auto delete of key using expirationTtl

ssandler•2/4/25, 9:44 PM

Has anyone run into troubles using otel-cf-workers for tracing with the latest durable objects sdk? workers-observability

iLearn•2/5/25, 6:01 AM

QQ regarding pricing behaviour of DO-KV :
While exercising Option "get(keys)", where keys will be an array .. assume 10 Keys are requested and 10 K-V are returned (assume total size of complete read is less than 4KB) .. my cost will 1 Read request units (and NOT 10 Keys x Price per Key Read, as behaved by Workers-KV) ? Please confirm.

IiLearn QQ regarding pricing behaviour of DO-KV : While exercising Option "get(keys)", w...

1984 Ford Laser•2/5/25, 7:57 AM

Nah

get()

get()

is a storage operation per key,

list()

list()

is per 4KB. If a single key in a get is over 4KB that will obvs be multiple ops

1984 Ford Laser•2/5/25, 7:59 AM

Learnt this one the hard way after I'd already determined a KV schema I liked. Will go back and optimise later, taking advantage of namespacing helps here. For example, if you had a number fields that belonged to a 'config' object, you might store each key as 'config-{key_name}' so then you're able to either pull the key itself, or all keys under 'config-' using list which is cheaper for reads

IiLearn Thanks for sharing your understanding. now i am in catch-22 situation .. wanted ...

lambrospetrou•2/5/25, 11:04 AM

Handling expiration after a TTL is quite trivial though if you need the single threaded coordination of DOs.
Attach a timestamp + a TTL on your values, and when reading them just check them against the current timestamp. If it's expired assume it didn't exist, and optionally delete it for cleanup. That's it.

Hard@Work•2/5/25, 11:06 AM

Hey @lambrospetrou, I forget, is there a way to push arbitrary objects into SQLite? I know that the backend can do it for SQLiteKV, but is there a way to do it when directly querying tables?

11984 Ford Laser Nah `get()` is a storage operation per key, `list()` is per 4KB. If a single key...

lambrospetrou•2/5/25, 11:06 AM

Check also the new SQLite DOs, since they could be much cheaper in terms of storage operations, depending on your access patterns: https://developers.cloudflare.com/durable-objects/platform/pricing/#sqlite-storage-backend

HHard@Work Hey @lambrospetrou, I forget, is there a way to push arbitrary objects into SQLi...

lambrospetrou•2/5/25, 11:07 AM

What do you mean by push arbitrary objects?

Llambrospetrou What do you mean by push arbitrary objects?

Hard@Work•2/5/25, 11:07 AM

Like how DOKV can store anything that can be

structuredClone

structuredClone

HHard@Work Like how DOKV can store anything that can be `structuredClone`d

lambrospetrou•2/5/25, 11:09 AM

SQLite supports bytes, so you could store anything if you convert it to bytes, or just serialize them on your own and store it as a blob or text. The conversion is not automatic though, you do it when you

INSERT

INSERT

rows.

Llambrospetrou SQLite supports bytes, so you could store anything if you convert it to bytes, o...

Hard@Work•2/5/25, 11:10 AM

That would require access to the V8 Serializer(or a custom one) within the runtime, which doesn't exist yet, right?

HHard@Work That would require access to the V8 Serializer(or a custom one) within the runti...

lambrospetrou•2/5/25, 11:13 AM

I am not sure if the Workers runtime provides that serializer for users, to be honest.

geg•2/5/25, 12:41 PM

I asked about it before

mentioned here:
durable-objects

Llambrospetrou SQLite supports bytes, so you could store anything if you convert it to bytes, o...

Hard@Work•2/5/25, 12:43 PM

Actually, Kenton has a good point about giving users access to serialisers directly(being that upgradability is nigh-on impossible if the user has to serialize data themselves). I'm not too familiar with SQLite Extensions/Plugins, but would it be possible to somehow add a serialiser to the SQLite API, so it wouldn't require direct access?

Original message was deleted

Hello, I’m Allie!•2/5/25, 12:53 PM

Not necessarily? I was thinking that it would be some kind of extension where, if it recognizes an “object” column, then all modifications pass through the serializer, so you can’t ever directly touch the bytes

Hard@Work•2/5/25, 12:55 PM

Yeah idk

Original message was deleted

lambrospetrou•2/5/25, 2:52 PM

Keep in mind this is your database, in your application, and your business logic is really tied to it. I personally wouldn't depend on some abstract serialization for putting data in my SQL database. For the KV API it's fine since that's abstracted from you higher up, you "put" an object and you "get" that object back. You don't have direct access to the underlying bytes.

With SQLite, you do since you say what goes into each row. It's your database tables. In that case I would favor using serialization that I control. You can migrate from one to another if you change your mind, or want better compression in size vs time, etc.

Hi, I need some clarifications regarding DO billing: - [1] "Each Durable Object stays alive as long

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