I use Durable Objects in remix and I made it so there is a backend worker handling the Durable Objec

I use Durable Objects in remix and I made it so there is a backend worker handling the Durable Object for each customer (they get a unique instance each), and the remix app uses RPC to interface with the worker

Ggruntlord6 I use Durable Objects in remix and I made it so there is a backend worker handli...

Silvan•5/7/25, 7:50 PM

out of curiosity. can you use

using

using

or Symbol.dipose in remix to dispose the rpc stub?

SSilvan out of curiosity. can you use `using` or [Symbol.dipose]() in remix to dispose t...

gruntlord6OP•5/7/25, 7:52 PM

dispose the stub?

Ggruntlord6 dispose the stub?

Silvan•5/7/25, 7:54 PM

https://developers.cloudflare.com/workers/runtime-apis/rpc/lifecycle/#explicit-resource-management

Cloudflare Docs

Lifecycle

Memory management, resource management, and the lifecycle of RPC stubs.

gruntlord6OP•5/7/25, 7:54 PM

I don't explicitly manage it because the durable object runs on alarms until it completes the queued work

gruntlord6OP•5/7/25, 7:55 PM

generally it could be as few as one task to tens of thousands, and remix is not designed for managing that nor would it really make sense given the context

Silvan•5/7/25, 9:07 PM

well its still good practice and sadly dosent really work in that environment

SSilvan well its still good practice and sadly dosent really work in that environment

gruntlord6OP•5/8/25, 1:14 AM

likely, but we only use the RPC to initiate the worker so we end the context very quickly and the documentation says that automatically disposes of it

gruntlord6OP•5/8/25, 1:15 AM

doing it cleanly is always ideal, but using remix with bindings wasn't super well documentated from what I could find

gruntlord6OP•5/8/25, 1:15 AM

I'd love if cloudflare had official demos for these platforms with remix next js etc, showing basic things like database bindings, r2 access etc

Fernando Barroso•5/8/25, 2:21 PM

Hey all! Do you know of any observability service that could show spans across a worker and a DO? I know baselime used to be the best option in past but idk what the latest is on that since acquisition.

Alex•5/8/25, 2:28 PM

I have not tried it but I do know Sentry recently released DO support which looks like it supports connected traces: https://github.com/getsentry/sentry-javascript/pull/16180

Fernando Barroso•5/8/25, 4:46 PM

This is coool!

CiRCUiT•5/9/25, 11:44 AM

I'm using Vercel's AI SDK, specifically the streamText function along with createDataStreamResponse, to send custom streaming data. I'd like to integrate this with a Cloudflare WebSocket setup using Durable Objects. What would be the best approach to achieve this integration?

Coshmar Tabletowy V•5/9/25, 12:32 PM

Hi all, whenever I try to write to Durable Object I have in live preview of the logs:

"executionModel": "durableObject", "outcome": "canceled",

Coshmar Tabletowy V•5/9/25, 12:32 PM

Is there any way to get the information why?

Elliot Hesp•5/9/25, 1:40 PM

Hey,

I believe I've found a prod vs local discrepancy with Durable Objects - where would I go about reporting this?

EElliot Hesp Hey, I believe I've found a prod vs local discrepancy with Durable Objects - wh...

lambrospetrou•5/9/25, 3:15 PM

Create a github issue in the wrangler repo if by local you mean

wrangler

wrangler

: https://github.com/cloudflare/workers-sdk/

Elliot Hesp•5/9/25, 3:15 PM

Thanks - well actually things work as expected locally, just not in prod

EElliot Hesp Thanks - well actually things work as expected locally, just not in prod

lambrospetrou•5/9/25, 3:24 PM

Describe the issue here, then. Without knowing what the discrepancy is I can't help.

Elliot Hesp•5/9/25, 3:32 PM

Ok so it does trigger in production

I think some code is erroring but I've no idea where logs are if an alarm throws an error

EElliot Hesp Ok so it does trigger in production 😮‍💨 I think some code is erroring but I've...

lambrospetrou•5/9/25, 3:39 PM

You can enable Observability logs for your worker project and you will be able to see your logs in the cloudflare dashboard. https://developers.cloudflare.com/workers/observability/logs/workers-logs/#enable-workers-logs

Elliot Hesp•5/9/25, 3:43 PM

Hmm, I do have that enabled, but I've just seen what's happening:

I have an endpoint setup which I am calling which accesses the DO (to logs the alarm)
If I don't call this endpoint, the alarm doesn't trigger
If I then call the endpoint, the alarm triggers - so accessing the DO seems to kick it off

Elliot Hesp•5/9/25, 3:43 PM

And I can see the RPC call which kicks it off includes the logs of the alarm call

EElliot Hesp Hmm, I do have that enabled, but I've just seen what's happening: - I have an e...

Milan•5/9/25, 4:14 PM

Maybe this? durable-objects

Elliot Hesp•5/9/25, 4:19 PM

@lambrospetrou @Milan

Ok so finally figured it out, I think:

My alarm calls a function

await doSomething()

await doSomething()

which is outside of the class (import function) which does an external async fetch call.

If that function thows an error (e.g.

if (!res.ok) throw new Error()

if (!res.ok) throw new Error()

) then the alarm just dies and no logs appear in console (hence me thinking it wasn't being triggered)

If I catch the error inline within the alarm

await doSomething().catch(e => console.error(e))

await doSomething().catch(e => console.error(e))

and return early, the alarm logs show up

So my issue was that I didn't think the alarm was being triggered because the alarm swallowed the errors/logs

EElliot Hesp @lambrospetrou @Milan Ok so finally figured it out, I think: My alarm calls a...

lambrospetrou•5/9/25, 4:24 PM

Yeah, as a guideline anything you do inside the

alarm()

alarm()

handler should be wrapped in a try-catch.

Elliot Hesp•5/9/25, 8:44 PM

Ok I've boiled the issue down to the following:

    this.ctx.blockConcurrencyWhile(async () => {
      await this.migrate();
    });

    this.ctx.blockConcurrencyWhile(async () => {
      await this.migrate();
    });

This is taken from; https://orm.drizzle.team/docs/connect-cloudflare-do

Seems like when the alarm tries to init the DO, it just explodes for some reason trying to the migration

Drizzle ORM - Cloudflare Durable Objects

Drizzle ORM is a lightweight and performant TypeScript ORM with developer experience in mind.

Elliot Hesp•5/9/25, 8:46 PM

The above was just a red herring it seems

jcheese•5/9/25, 11:03 PM

Is there a way to “re-instantiate” a specific do?

Jjcheese Is there a way to “re-instantiate” a specific do?

1984 Ford Laser•5/9/25, 11:10 PM

What do you mean by that exactly? you can delete its storage which essentially resets it

11984 Ford Laser What do you mean by that exactly? you can delete its storage which essentially r...

jcheese•5/9/25, 11:14 PM

theres some DOs that just give "internal error; reference = moh644b953d9vckab1seqm9a" and I cant access it at all

jcheese•5/9/25, 11:14 PM

like i want to delete them and re-make it from scratch

1984 Ford Laser•5/9/25, 11:14 PM

Is that just by running the constructor? What is the instance trying to do when it errors like that

1984 Ford Laser•5/9/25, 11:15 PM

You can only delete them from within

Victor•5/10/25, 12:26 AM

Does anyone know the exact error message when a SQLite DO exceeds the 10gb of storage?

Victor•5/10/25, 1:02 AM

I made a random generator and filled a local DO, but it appears wrangler local doesn't simulate the 10GB cap

sathoro•5/10/25, 1:23 PM

my guess is RangeError

planet•5/10/25, 4:13 PM

could look at databaseSize

aza547•5/10/25, 6:51 PM

Hello, I'm looking at using Durable Objects as a Websocket server. I'm a bit confused by the Hibernate API, and this SO post.

Since DurableObjects are basically in-memory classes, their long-term state cannot be guaranteed - especially in cases which involve the Hibernation API. When the DurableObject hibernates, the existing websocket connections are kept alive "outside" of the class - and when one wakes up, the Workers runtime will reinstantiate the DurableObject with a new state.

My confusion is that I thought the whole point of DO was to be a "stateful worker". But this comment seems to claim the opposite (might just be bogus). That said, the docs also claim that:

// ... During periods of inactivity, the Durable Object can be evicted
// from memory, but the WebSocket connection will remain open. If at some later point the
// WebSocket receives a message, the runtime will recreate the Durable Object
// (run the
constructor
constructor
) and deliver the message to the appropriate handler.

Am I misunderstanding the point of DOs? Or is this just an edge case with the hibernate API and I should use

serializeAttachment

serializeAttachment

deserializeAttachment

deserializeAttachment

to store persistent state?

Aaza547 Hello, I'm looking at using Durable Objects as a Websocket server. I'm a bit con...

Unsmart•5/10/25, 7:48 PM

Durable objects are not exclusive in memory storage and can absolutely store stuff permanently (that is indeed the entire point of them wouldnt be durable otherwise).

The attachments on a websocket connection will exist as long as the client is connected regardless of the DO being evicted and then reinstated down the line. However, if the client disconnects then the attachment will go away.

You can use memory only state that doesnt get durably stored if you wanted but you can also use durable storage.

aza547•5/10/25, 9:58 PM

Ah I see. Seems the bit I was missing is that that durable storage is separate from the memory state. RTFM I guess. Thanks for the help.

veeque•5/11/25, 2:24 PM

if a durable object is "hot" (so if i was to make a new request now the constructor would not run) and I deploy a new version in the meantime, would the constructor run again (kinda like "shutting down" the DO)?

Wwilb.me Hi! I'm trying to figure out if a singleton Durable Object makes sense as a cons...

1984 Ford Laser•5/12/25, 9:52 AM

If its 24/7 operation then yeah VPS will probably be best at the moment, Containers are coming to CF :soontm: which might be a better solution that's on-platform

Wwilb.me Thanks! I was hoping some magic around "idle but active websocket connection" wo...

1984 Ford Laser•5/12/25, 10:00 AM

My hope is that using DOs as a hibernatable client will be possible in the future, but nothing specific has been hinted at yet. I'm super keen for containers, I have so many interesting use cases

Wwilb.me Hi! I'm trying to figure out if a singleton Durable Object makes sense as a cons...

Larry•5/12/25, 1:19 PM

Have you considered using the "backfill window" capability of ATProto combined with an alarm that is shorter than that window to accomplish the same thing. I'm not familiar with Jetstream, but maybe it supports this.

Alternatively, you could use CBOR-X over WebSockets to subscribe directly to ATProto. It seems like the only thing Jetstream provides is converting CBOR to JSON, but that's what CBOR-X does as a library instead of a service.

echoes221•5/12/25, 3:13 PM

With durable object migrations, do I need to do migrations for each env? Or just a top level one?