Is there a way for a DO instance to know what binding name was used to connect to it without explici

LLarry Is there a way for a DO instance to know what binding name was used to connect t...

H

Not yet. The tricky part is that names aren’t bounded by size, so theoretically you could have a 50 MB name, which is not great to be shipping around the world. Though iirc the team is looking into supporting it somehow

A

ALECKS•10/27/25, 3:35 PM

I'm seeing some strange behavior after destroying a durable object.

I have this destory method():

async destroy() {
    // drop all tables
    this.sql`DROP TABLE IF EXISTS state`;
    this.sql`DROP TABLE IF EXISTS alarms`;
    this.sql`DROP TABLE IF EXISTS jobs`;

    // delete all alarms
    try {
      await this.ctx.storage.deleteAlarm();
      await this.ctx.storage.deleteAll();
      this.logger.info(`Destroying Durable Object ${this.ctx.id.toString()}`);
      this.logger.info(`Alarm: ${await this.ctx.storage.getAlarm()}`);
      this.ctx.abort("destroyed");
    } catch (_) {}
  }

async destroy() {
    // drop all tables
    this.sql`DROP TABLE IF EXISTS state`;
    this.sql`DROP TABLE IF EXISTS alarms`;
    this.sql`DROP TABLE IF EXISTS jobs`;

    // delete all alarms
    try {
      await this.ctx.storage.deleteAlarm();
      await this.ctx.storage.deleteAll();
      this.logger.info(`Destroying Durable Object ${this.ctx.id.toString()}`);
      this.logger.info(`Alarm: ${await this.ctx.storage.getAlarm()}`);
      this.ctx.abort("destroyed");
    } catch (_) {}
  }

async destroy() {
    // drop all tables
    this.sql`DROP TABLE IF EXISTS state`;
    this.sql`DROP TABLE IF EXISTS alarms`;
    this.sql`DROP TABLE IF EXISTS jobs`;

    // delete all alarms
    try {
      await this.ctx.storage.deleteAlarm();
      await this.ctx.storage.deleteAll();
      this.logger.info(`Destroying Durable Object ${this.ctx.id.toString()}`);
      this.logger.info(`Alarm: ${await this.ctx.storage.getAlarm()}`);
      this.ctx.abort("destroyed");
    } catch (_) {}
  }

async destroy() {
    // drop all tables
    this.sql`DROP TABLE IF EXISTS state`;
    this.sql`DROP TABLE IF EXISTS alarms`;
    this.sql`DROP TABLE IF EXISTS jobs`;

    // delete all alarms
    try {
      await this.ctx.storage.deleteAlarm();
      await this.ctx.storage.deleteAll();
      this.logger.info(`Destroying Durable Object ${this.ctx.id.toString()}`);
      this.logger.info(`Alarm: ${await this.ctx.storage.getAlarm()}`);
      this.ctx.abort("destroyed");
    } catch (_) {}
  }

When it executes, I see normal logs:

Destroying Durable Object 130f15d64c383661002b1c10796016628280fda1f20c1557eb8ff89543479444
Alarm: null 
✘ [ERROR] Uncaught Error: destroyed

Destroying Durable Object 130f15d64c383661002b1c10796016628280fda1f20c1557eb8ff89543479444
Alarm: null 
✘ [ERROR] Uncaught Error: destroyed

Destroying Durable Object 130f15d64c383661002b1c10796016628280fda1f20c1557eb8ff89543479444
Alarm: null 
✘ [ERROR] Uncaught Error: destroyed

Destroying Durable Object 130f15d64c383661002b1c10796016628280fda1f20c1557eb8ff89543479444
Alarm: null 
✘ [ERROR] Uncaught Error: destroyed

Then strangely, a few seconds later I see this:

Creating DO tables (alarms, jobs, state)   // this is logged from my DO's constructor
NOSENTRY SQLite alarm handler canceled with requestScheduledAlarm.; scheduledTime = 1761578532s; localAlarmState.orDefault(kj::UNIX_EPOCH) = 0ns; actorId = 130f15d64c383661002b1c10796016628280fda1f20c1557eb8ff89543479444

Creating DO tables (alarms, jobs, state)   // this is logged from my DO's constructor
NOSENTRY SQLite alarm handler canceled with requestScheduledAlarm.; scheduledTime = 1761578532s; localAlarmState.orDefault(kj::UNIX_EPOCH) = 0ns; actorId = 130f15d64c383661002b1c10796016628280fda1f20c1557eb8ff89543479444

Creating DO tables (alarms, jobs, state)   // this is logged from my DO's constructor
NOSENTRY SQLite alarm handler canceled with requestScheduledAlarm.; scheduledTime = 1761578532s; localAlarmState.orDefault(kj::UNIX_EPOCH) = 0ns; actorId = 130f15d64c383661002b1c10796016628280fda1f20c1557eb8ff89543479444

Creating DO tables (alarms, jobs, state)   // this is logged from my DO's constructor
NOSENTRY SQLite alarm handler canceled with requestScheduledAlarm.; scheduledTime = 1761578532s; localAlarmState.orDefault(kj::UNIX_EPOCH) = 0ns; actorId = 130f15d64c383661002b1c10796016628280fda1f20c1557eb8ff89543479444

After it's destroyed, something else wakes up the DO only to warn me that an alarm was replaced. Why is this happening?

A

ALECKS•10/27/25, 5:01 PM

Yes, the destroy() is called from within an alarm.. it's a sort of TTL where I tell the DO to destroy itself sometime in teh future. I do catch the exception thrown by abort() tho...

A

ALECKS•10/27/25, 5:02 PM

and the destory is working, i can see everything wiped in the sqlite file

A

ALECKS•10/27/25, 5:04 PM

that I don't know, just following code i saw in some examples

HHello, I’m Allie!Not yet. The tricky part is that names aren’t bounded by size, so theoretically ...

L

LarryOP•10/27/25, 5:11 PM

Thanks, while we're on the subject, is

ctx.id

ctx.id

ctx.id

ctx.id always valid even when you got to the DO via

getByName()

getByName()

getByName()

getByName(), meaning I can use it as a "return address" for in-Cloudflare communication even if my client-side application always uses the name?

LLarry Thanks, while we're on the subject, is `ctx.id` always valid even when you got t...

H

Hard@Work•10/27/25, 5:27 PM

It should be, since

getByName

getByName

getByName

getByName is just a convenience utility mapping to

.get(DO.idFromName()

.get(DO.idFromName()

.get(DO.idFromName()

.get(DO.idFromName() I think

LLarry Thanks, while we're on the subject, is `ctx.id` always valid even when you got t...

L

lambrospetrou•10/27/25, 5:45 PM

Yes, the ID is always populated and correct. And you can route to a DO by the ID even if other callers route by name.

L

LarryOP•10/27/25, 5:51 PM

I don't see a channel for Cloudflare Queues but please excuse me if this is the wrong channgel to ask on, but what's the expected latency for Cloudflare Queues between the time you push a message in and the time your Queue consumer is called?

LLarry I don't see a channel for Cloudflare Queues but please excuse me if this is the ...

C

Chaika•10/27/25, 6:00 PM

#queues

C

Chaika•10/27/25, 6:01 PM

it can def take a few seconds though How to make queues pick up messages

L

LarryOP•10/27/25, 6:28 PM

I am never sure I get the unit conversions correct. I've seen folks say it costs about $4/month to run a DO 24/7, but I've also seen $0.34/day which works out to about $10/month. Can someone show me the math?

LLarry I am never sure I get the unit conversions correct. I've seen folks say it costs...

L

lambrospetrou•10/27/25, 6:37 PM

1 DO running 24/7 needs:

0.128 GB-s * 3600 seconds_per_hour * 744 hours_in_month = 342_835 GB-s/month

0.128 GB-s * 3600 seconds_per_hour * 744 hours_in_month = 342_835 GB-s/month

0.128 GB-s * 3600 seconds_per_hour * 744 hours_in_month = 342_835 GB-s/month

0.128 GB-s * 3600 seconds_per_hour * 744 hours_in_month = 342_835 GB-s/month and at the price

$12.50/million GB-s

$12.50/million GB-s

$12.50/million GB-s

$12.50/million GB-s that's 4.285 USD/month (

342_835/1_000_000*12.50

342_835/1_000_000*12.50

342_835/1_000_000*12.50

342_835/1_000_000*12.50).
You get 400,000 GB-s for free.

The above is duration only charges.

edit: using the correct

0.128 GB-s

0.128 GB-s

0.128 GB-s

0.128 GB-s vs

0.125GB-s

0.125GB-s

0.125GB-s

0.125GB-s

L

LarryOP•10/27/25, 6:38 PM

Thanks! I only need duration charge help. I can count requests, just not unit convert.

P

PhoenixSpace•10/27/25, 6:53 PM

Is there any way to get a hook to run code before a DO is evicted from memory? Would love to use it to flush in memory stuff to sql storage rather than needing to write a value that will be modified often in short bursts.

PPhoenixSpace Is there any way to get a hook to run code before a DO is evicted from memory? W...

L

LarryOP•10/27/25, 6:56 PM

There is no such hook and even if there were, it wouldn't always work because it can evicted for crazy reasons. The saving grace is that reading from and writing to storage is very fast due to caching and locality. I have switched to a coding style where I don't have instance variables unless the in-memory representation is an expensive transformation from the in-storage representation. It's counter-intuitive but think of storage like you used to think of instance variables.

L

LarryOP•10/27/25, 7:04 PM

For the cases where the in-memory transformation is expensive, I have also adopted a coding style where I save and retrieve that largish structure in one whole shot using the fact that the KV API let's you store just about everything (objects with cycles or aliases, Date, Map, Set, Infinity, NaN, etc.). See the complete list in the second column here

LLarry There is no such hook and even if there were, it wouldn't always work because it...

P

PhoenixSpace•10/27/25, 7:05 PM

That's pretty fair, wishful thinking I guess. Wanted to avoid the $1/million write charges because it's an extremely bursty workflow (counting a rapid stream of events), but honestly not that bad

P

PhoenixSpace•10/27/25, 7:05 PM

the storage backend KV-like API for sqlite is OP though

L

LarryOP•10/27/25, 7:08 PM

Reads are so inexpensive I ignore the cost. Write costs can add up.

P

PhoenixSpace•10/27/25, 7:08 PM

Yup, that's why I was wondering if I could just flush it with a handle

P

PhoenixSpace•10/27/25, 7:09 PM

Guess this might be a better task for a container

L

LarryOP•10/27/25, 7:10 PM

I don't know the costs for containers but I find it hard to image it would be less under the vast majority of circumstances.

P

PhoenixSpace•10/27/25, 7:56 PM

On average it will undergo ~250,000 events in a 8 minute span, and then go silent for up to a month, so about $0.25 in writes vs probably a couple cents for the container

P

PhoenixSpace•10/27/25, 7:56 PM

very niche/weird usecase lol

PPhoenixSpace On average it will undergo ~250,000 events in a 8 minute span, and then go silen...

1

1984 Ford Laser•10/27/25, 8:24 PM

Could the events be grouped in some way? Store groups of events per write request

L

LarryOP•10/27/25, 8:27 PM

For $0.25, I wouldn't bother optimizing. Not even for $25. Maybe at $250 if it was simple to implement and manage but containers are generally harder to manage in my experience.

11984 Ford Laser Could the events be grouped in some way? Store groups of events per write reques...

P

PhoenixSpace•10/27/25, 8:39 PM

Unfortunately I don’t control that side. Been asking for that, but they don’t want to do it

LLarry For $0.25, I wouldn't bother optimizing. Not even for $25. Maybe at $250 if it w...

P

PhoenixSpace•10/27/25, 8:41 PM

I totally agree, but I’m basically donating the cost to manage this out of pocket currently. I was originally going to just spin up a VPS but figured scale to zero could save a bit (and scale horizontally since I don’t know how many events per month will be happening initially)

P

PhoenixSpace•10/27/25, 8:42 PM

It’s for managing some stuff for a highschool competition being spun up. Infra is a bit of a mess but until it goes public and gets sponsored basically just doing it for free.

PPhoenixSpace It’s for managing some stuff for a highschool competition being spun up. Infra i...

1

1984 Ford Laser•10/27/25, 8:44 PM

If it is actually only once a month then you'll stay within the included limits with workers paid anyway

1

1984 Ford Laser•10/27/25, 8:45 PM

Doing lots of writes sucks but I wouldnt worry unless your use case would easily push you over included limits

11984 Ford Laser If it is actually only once a month then you'll stay within the included limits ...

P

PhoenixSpace•10/27/25, 8:45 PM

It’s once a month per team per event

1

1984 Ford Laser•10/27/25, 8:45 PM

ahhh

P

PhoenixSpace•10/27/25, 8:45 PM

And I have no clue what the number of teams or events will be

1

1984 Ford Laser•10/27/25, 8:45 PM

THat might be an issue lol

P

PhoenixSpace•10/27/25, 8:46 PM

Yeah

1

1984 Ford Laser•10/27/25, 8:46 PM

What are you doing with the data afterwards?

P

PhoenixSpace•10/27/25, 8:46 PM

It gets processed into a leaderboard, basically

P

PhoenixSpace•10/27/25, 8:46 PM

Hmm. It just occurred to me this could totally be done with WAE

P

PhoenixSpace•10/27/25, 8:47 PM

Probably much simpler

1

1984 Ford Laser•10/27/25, 8:47 PM

I wonder if you could store the entire 300k events as a single object in R2 then just process them when you need them via streaming into a Worker?

PPhoenixSpace Hmm. It just occurred to me this could totally be done with WAE

1

1984 Ford Laser•10/27/25, 8:47 PM

or this maybe

P

PhoenixSpace•10/27/25, 8:48 PM

Yeah, I’ll probably just use WAE lmao

1

1984 Ford Laser•10/27/25, 8:48 PM

300k events for a leaderboard is wild to me, what are you doing exactly lol? If youre allowed to talk a bit more about it

1

1984 Ford Laser•10/27/25, 8:49 PM

ahh I see WAE is only 0.25 per mil writes

P

PhoenixSpace•10/27/25, 8:50 PM

Honestly I don’t know a lot of details. Friend came to me and asked for help with the data pipeline. As far as I know it’s some tech related challenge thing, and certain events generate milestones they have to track with some light validation in worker. AFAIK their reasoning for not batching was concern someone would be able to edit it on the computer before the batch is pushed (this seems like something you can design around but I’m not making that part)

11984 Ford Laser ahh I see WAE is only 0.25 per mil writes

1

1984 Ford Laser•10/27/25, 8:52 PM

oh and you only get charged per read query not per row thats kinda crazy

P

PhoenixSpace•10/27/25, 8:53 PM

tbh it sounded like a fun excuse to do more with cloudflare and that’s all I really paid attention to

PPhoenixSpace tbh it sounded like a fun excuse to do more with cloudflare and that’s all I rea...

1

1984 Ford Laser•10/27/25, 8:53 PM

Honestly if you ignored costs there's probably a dozen different ways to use CF products to do this