Am getting `error setting identifier TypeError: this.parent.setName is not a function` when running

Am getting

error setting identifier TypeError: this.parent.setName is not a function

error setting identifier TypeError: this.parent.setName is not a function

error setting identifier TypeError: this.parent.setName is not a function

error setting identifier TypeError: this.parent.setName is not a function
when running

await this.alarms.alarm();

await this.alarms.alarm();

await this.alarms.alarm();

await this.alarms.alarm();

the alarm seems to still work actually. Not sure what the setName function is for since it's not in any of the examples. (https://github.com/cloudflare/actors/blob/e910e86ac1567fe58e389d1938afbdf1e53750ff/examples/durable-objects/src/index.ts)

GitHub

actors/examples/durable-objects/src/index.ts at e910e86ac1567fe58e3...

An easier way to build with Cloudflare Durable Objects - cloudflare/actors

1984 Ford Laser•11/5/25, 4:59 AM

Assuming that the DO is not processing any other requests in between, will a 1second alarm interval always execute as close to 1000 milliseconds as possible (also assuming everything else in the universe works as expected)? Has anyone benchmarked performance here? I have a counting timer that I want to synchronize between clients, my current process tells all clients when to start counting (providing a datetime ground truth), then each client handles their own timeouts to manage counting up. I would prefer to sync over WS but only if I can keep the interval as close to 1000ms as possible. The timer is used for tracking state in sports matches, so if each tick is more than 10ms out of sync then it'll add up very quickly

11984 Ford Laser Assuming that the DO is not processing any other requests in between, will a 1se...

PhoenixSpace•11/5/25, 5:33 AM

I would prefer to sync over WS

No idea about the timer precision (I'd imagine there is some variability there), but websocket jitter would be more then 10ms, right?

1984 Ford Laser•11/5/25, 5:43 AM

I'll be lucky to have more than 5 clients connected at a time, in my experience sending simple WS messages can be completed in single millisecond timeframes. I can also do an interval of under 1second (say 975ms) if I know I'm going to have a semi predictable delay with each tick (I do this currently with awful accuracy lmao)

11984 Ford Laser Assuming that the DO is not processing any other requests in between, will a 1se...

lambrospetrou•11/5/25, 9:36 AM

I don't know the numbers off my head, but I can easily see it breaching the 1s throughout the day. Also, keep in mind that a single retry starts with a 2s exponential backoff, so you already are way ahead of your limit there. That is if there is a possibility your handler will fail.

Llambrospetrou I don't know the numbers off my head, but I can easily see it breaching the 1s t...

Larry•11/5/25, 1:18 PM

Is this a troublesome use case for Alarms? Just by listening to people talk about on here, including you, I'm getting the feeling that anything less than a minute, might be troublesome?

LLarry Is this a troublesome use case for Alarms? Just by listening to people talk abou...

lambrospetrou•11/5/25, 2:00 PM

I know many users do Alarms with such low frequencies, I do a few seconds myself too, but requiring every second accuracy seems a very easy thing to go wrong, in my opinion.
At that rate the DO is always active anyway, so probably using a larger alarm and then setTimeout could give you more accuracy. The alarm would only be for making sure you get external retries in case of a crash.
At least that's my current approach for few things. But, as always it depends on the use-case. I don't know if there is a hard guarantee on alarm invocation time at the tens of milliseconds level.

NNeed_Not Am getting `error setting identifier TypeError: this.parent.setName is not a fun...

Need_NotOP•11/5/25, 5:29 PM

any idea about this?

Llambrospetrou I know many users do Alarms with such low frequencies, I do a few seconds myself...

gruntlord6•11/5/25, 6:00 PM

in general you need to be careful with alarms. Its very easy to accidentally have them loop with short timers or by having a memory error in something tied to an alarm. I generally do every 10 seconds if being in memory already would benefit the task or 30+ seconds if it doesn't or if I don't want to have a huge rush of requests

gruntlord6•11/5/25, 6:01 PM

I also use them all the time since its an extremly usefull way to handle long running tasks entirely in code, but its a double edged sword and can add complexity if not properly setup

gruntlord6•11/5/25, 6:05 PM

I haven't tried it yet, but if anyone is trying to do a lot with durable objects then its probably worth looking into using lumenize to have workers handle the actual fetch etc to be more efficient and save on billing https://lumenize.com/docs/proxy-fetch/

Proxy Fetch | Lumenize

Offload Requests to a Worker and/or a Durable Object and have it execute a handler when the fetch is done

Ggruntlord6 I haven't tried it yet, but if anyone is trying to do a lot with durable objects...

PhoenixSpace•11/5/25, 6:12 PM

(I think your link is malformed)

PPhoenixSpace (I think your link is malformed)

gruntlord6•11/5/25, 6:46 PM

you don't visit the .com root every day? Thanks

Llambrospetrou I don't know the numbers off my head, but I can easily see it breaching the 1s t...

1984 Ford Laser•11/5/25, 9:46 PM

Appreciate the discussion on this. My use case only needs to stay within a few seconds for around 30 minutes at a time. I'm also not fussed about forcing the DO active as it will only be for a few hours a week per DO (maybe 20 DO instances total) so not any decent scale. Sounds like I need to not stress so much about syncing every second, will have a bit of a think about it

1534980751438970153470891543•11/5/25, 10:04 PM

does the durable object jurisdiction param only matter upon creation

1534980751438970153470891543•11/5/25, 10:06 PM

i.e. create the DO with the eu jurisdiction param (once), then omit the param forever afterwards

1534980751438970153470891543•11/5/25, 10:07 PM

knowing this will either be a few or many lines of change

11534980751438970153470891543 i.e. create the DO with the eu jurisdiction param (once), then omit the param fo...

Hard@Work•11/5/25, 10:07 PM

I would just keep it, there isn't really a reason not to send it

1534980751438970153470891543•11/5/25, 10:08 PM

im just wondering if its redundant

11534980751438970153470891543 im just wondering if its redundant

Hard@Work•11/5/25, 10:09 PM

It shouldn't be? Though actually, it might error if you don't provide it?

1534980751438970153470891543•11/5/25, 10:10 PM

1534980751438970153470891543•11/5/25, 10:10 PM

so it isnt redundant

Hard@Work•11/5/25, 10:11 PM

Yeah

1534980751438970153470891543•11/5/25, 10:11 PM

thanks

boop•11/5/25, 10:45 PM

If you generate and query by name, you have to supply the jurisdiction. If you use durable object IDs, the jurisdiction is embedded in the ID so you don't have to limit the namespace. This has been my experience

calvinfo•11/5/25, 10:47 PM

hey folks, supposing I wanted to bind a sandbox to an internal service (separate DO), is that possible? I was digging around the docs and didn't find anything too promising, but wanted to double check here.

basically I want to be able to do something like:

worker → create sandbox, execute commands in a loop → sandbox-backend (handles things like auth)

feel free to also redirect me if there's a better channel

Ccalvinfo hey folks, supposing I wanted to bind a sandbox to an internal service (separate...

Hard@Work•11/5/25, 11:30 PM

?crossposting

SuperHelpflare•11/5/25, 11:30 PM

Please do not post your question in multiple channels/post it multiple times per the rules at #

welcome-and-rules. It creates confusion for people trying to help you and doesn't get your issue or question solved any faster.

Ccalvinfo hey folks, supposing I wanted to bind a sandbox to an internal service (separate...

Larry•11/5/25, 11:33 PM

The Worker to DO pattern is the norm, but I'm uncertain what you mean by "sandbox". Is it untrusted code?

LLarry The Worker to DO pattern is the norm, but I'm uncertain what you mean by "sandbo...

1984 Ford Laser•11/5/25, 11:43 PM

Probably the CF Sandbox SDK https://developers.cloudflare.com/sandbox/ which is basically containers with a wrapper

11984 Ford Laser Probably the CF Sandbox SDK https://developers.cloudflare.com/sandbox/ which is ...

Larry•11/6/25, 12:04 AM

Ahh, makes sense. I'm unfamiliar with that product, although I think it would be cool to get my AI Coding Agent to run in one of them. Just not sure how I'd see the output.

LLarry Ahh, makes sense. I'm unfamiliar with that product, although I think it would be...

1984 Ford Laser•11/6/25, 12:05 AM

Stream it back via WebSockets

11984 Ford Laser Stream it back via WebSockets

Larry•11/6/25, 12:34 AM

Would need something like that. I'm sure someone has already built that or will soon.

mau•11/6/25, 2:50 AM

Request/Question:

I was wondering if there’s a way to perform a cross join between data stored in different Durable Object tables — similar to how PostgreSQL uses foreign data wrappers (FDWs). It would be game changer.

Mmau Request/Question: I was wondering if there’s a way to perform a cross join betw...

Larry•11/6/25, 3:41 AM

That would be a neat trick, but I've never heard of anything like that, and I probably would have if it existed.

LLarry Would need something like that. I'm sure someone has already built that or will ...

ALECKS•11/6/25, 4:13 AM

It's built in, you can open a ws to anything insider your sandbox
https://developers.cloudflare.com/sandbox/guides/websocket-connections/

AALECKS It's built in, you can open a ws to anything insider your sandbox https://devel...

Larry•11/6/25, 4:19 AM

It's good to know that the WebSocket part is already built in. Do you know anyone who is using it as a remote AI coding platform? I'd love to hear more about the setup.

ALECKS•11/6/25, 4:21 AM

No I just recently found out about this myself. Looks like a killer offering tho... docker container, with DO-like ergonomics

ALECKS•11/6/25, 4:29 AM

Does anyone happen to know, if you call a DurableObject via RPC, does that implicitly also wake up its associated Worker?

To ask differently. Do I get billed more if I do:
CallerA -> WorkerB.rpc() -> DO-B.rpc()
vs
CallerA -> DO-B.rpc()

AALECKS Does anyone happen to know, if you call a DurableObject via RPC, does that impli...

Larry•11/6/25, 5:08 AM

What is CallerA? Is it client-side (browser or app)? Workers RPC is between Workers, DOs, and RpcTargets. If you want all the way to the client, you need something like Cap'n Web or Lumenize RPC. If you are just using Workers RPC, the called DO is accessed directly without the involvement of the Worker in the module where that DO is defined.

Kunal Verma•11/6/25, 7:31 AM

how can I view storage.kv/_cf_KV items for remote durable objects?

scruffy•11/6/25, 10:35 AM

Hihi! If I spin up a Durable Object to store session data via the KV API and give the data an expiry via TTL, will the Durable Object still exist after the data's expired? If so, is there any residual wrapper that might incur storage costs?

Sscruffy Hihi! If I spin up a Durable Object to store session data via the KV API and giv...

Larry•11/6/25, 12:19 PM

Workers KV has expiration dates but the KV inside a DO does not. You'd have to implement that yourself, or use Workers KV.

KKunal Verma how can I view storage.kv/_cf_KV items for remote durable objects?

Larry•11/6/25, 12:30 PM

You can add a method on the remote DO that returns it and then call that method remotely using Workers RPC. So, this.env.REMOTE_DO.getByName('remote-instance-name').get_cf_KV()this.env.REMOTE_DO.getByName('remote-instance-name').get_cf_KV(). If you are going to call the remote DO more times, I recommend that you two-step it and put the the remote DO stub in a variable. So:

const remoteStub = this.env.REMOTE_DO.getByName('remote-instance-name');
const remote_cf_KV = remoteStub.get_cf_KV();

const remoteStub = this.env.REMOTE_DO.getByName('remote-instance-name');
const remote_cf_KV = remoteStub.get_cf_KV();

if you are using id's instead of instance names its:

const remoteId = this.env.REMOTE_DO.getIdFromString('23abc...');  // 64 byte opaque hex
const remoteStub = this.env.REMOTE_DO.get(remoteId);
const remote_cf_KV = remoteStub.get_cf_KV();

const remoteId = this.env.REMOTE_DO.getIdFromString('23abc...');  // 64 byte opaque hex
const remoteStub = this.env.REMOTE_DO.get(remoteId);
const remote_cf_KV = remoteStub.get_cf_KV();

The only tricky part most of the time is knowing the id or name of the remote DO.

LLarry Workers KV has expiration dates but the KV inside a DO does not. You'd have to i...

scruffy•11/6/25, 12:56 PM

thanks for the info. in terms of how to implement in DO, is this only doable via alarms or are there other alternatives?

Bboop If you generate and query by name, you have to supply the jurisdiction. If you u...

1534980751438970153470891543•11/6/25, 6:04 PM

that wouldve saved me a lot of work lol....

1534980751438970153470891543•11/6/25, 6:06 PM

at least it looks consistent... i added jurisdiction even when using the DO IDs

WWallslide When I'm running a worker locally, how can I clear out my local durable objects

Hard@Work•11/6/25, 11:55 PM

You can nuke the

.wrangler

.wrangler

directory, or find the specific DO namespace folder and delete it