Cloudflare Developers•3y ago

I guess this was before alarms

johtsoOP•3/12/23, 12:40 PM

And now alarms are basically the tool for all lifecycle related things?

Jjohtso I guess this was before alarms

Hello, I’m Allie!•3/12/23, 12:41 PM

This is probably the answer, from the thread:

You can build a TTL using alarms. Whenever your object is accessed, you would use setAlarm()setAlarm() to set the alarm time to Date.now() + timeoutDate.now() + timeout. There is only one alarm per object, so each call to setAlarm()setAlarm() replaces the previous alarm with the new alarm time. When that time is reached, the alarm handler will be invoked. In your alarmalarm handler, you would use storage.deleteAll()storage.deleteAll() to delete your object.

Since it’s possible to build TTL using alarms, we probably won’t be adding a separate TTL feature.

- Kenton

johtsoOP•3/12/23, 12:45 PM

Ah well spotted

johtsoOP•3/12/23, 12:46 PM

I guess better that energy is put towards stuff that can't be done in user land

SSubh Hey team, I removed one DO call and one Queue call, my api response time down fr...

Larry•3/12/23, 6:28 PM

I don't think you provided enough details to make a full diagnosis and even if you did, I have no experience with queues and I'm far from knowing all the ins and outs of DO performance. One wild ass guess though... do you use env.MY_DO_NAMESPACE.idFromName(name)env.MY_DO_NAMESPACE.idFromName(name)? Those require a global lookup on object creation and should be avoided.

johtsoOP•3/13/23, 1:12 AM

just found this too https://github.com/ticket-bridge/hyper-durable

johtsoOP•3/13/23, 1:14 AM

the extra layer of abstraction it proposes makes my head hurt though

Chaika•3/13/23, 4:04 PM

You can use location hints to "hint" that it should be within a specific region: https://developers.cloudflare.com/workers/runtime-apis/durable-objects/#providing-a-location-hint, as well as restricting objects to a specific jurisdiction (like for GDPR), but nothing direct to a specific colo. Not all colos support Durable Objects either (https://where.durableobjects.live/)

Jacob Wright•3/13/23, 5:15 PM

Does anyone know if a DO connects to another via websocket, will they both stay open until one of them closes the socket connection, or will they shut down after no external requests have been made to them?

Jacob Wright•3/13/23, 6:13 PM

Is there a possible race condition if 2 requests call idFromNameidFromName with the same never-before-used name? Or are there guards around that?

JJacob Wright Is there a possible race condition if 2 requests call `idFromName` with the same...

DaniFoldi•3/13/23, 6:18 PM

I've tested that and it was fine, the first one (1-2ms apart) got it, and if my memory serves me right, idFromName first checks with a global coordinator before "assigning" it to the closest colo, hence the increased perceived latency of the first request

DaniFoldi•3/13/23, 6:19 PM

I'm assuming all colos have a map of ids stored so subsequent accesses are faster, so it's just a first-time thing

DDaniFoldi I've tested that and it was fine, the first one (1-2ms apart) got it, and if my ...

Jacob Wright•3/13/23, 10:51 PM

So you think the global coordinator is able to ensure only 1 DO by name exists, even if 2 requests come in at the same time for a new name? Thank you for your feedback. I'll also be sure to test it, but that's good to know.
It's interesting idFromNameidFromName doesn't return a promise since it can be async.

JJacob Wright So you think the global coordinator is able to ensure only 1 DO by name exists, ...

Hello, I’m Allie!•3/13/23, 10:52 PM

That’s because the check doesn’t actually occur until the stub is fetched the first time

HHello, I’m Allie!That’s because the check doesn’t actually occur until the stub is fetched the fi...

Jacob Wright•3/13/23, 10:59 PM

Ah. So if a worker in NA calls idFromName('new-name')idFromName('new-name') and a worker in EU calls idFromName('new-name')idFromName('new-name') at the same time, they'll both have different ids. When they call fetch(req)fetch(req) will they both get a different DO instance, or will the system ensure they are routed to the same DO? I'm looking at using the DO mechanism so that multiple players of an AI text game who are hitting the same un-generated branch of that game will be able to request it and have a unique DO for that branch ensure the request to generate the AI response only happens once and is returned to both players and caches the response in R2 for future players who go down that particular branch. I'm not sure if the guarantee for 1 DO in the world for a given name extended to this case when 2 clients could be asking for the same new name at the same moment.

JJacob Wright Ah. So if a worker in NA calls `idFromName('new-name')` and a worker in EU calls...

Larry•3/14/23, 12:18 PM

The intention is that the initial NA and EU idFromNameidFromName calls will meet up somewhere in the ether and one will win so that there will only ever be one DO that matches that "name". This cross coordination occurs before a fetch can be called, so they will be "routed to the same DO". That said, I don't know if anyone on this channel has seen the actual code and sequence diagrams that confirm it achieves this intention, but if it doesn't work this way, it's a bug, not expected.

Cckoeninger you don't need global coordination to get a consistent id from a given name. th...

Hello, I’m Allie!•3/14/23, 2:19 PM

Might have asked this before, but any plans to have a way to get the current “region” from within a DO?

Cckoeninger aside from the previously widely discussed unsupported hack that will likely be ...

Hello, I’m Allie!•3/14/23, 2:20 PM

Do tell?

Cckoeninger aside from the previously widely discussed unsupported hack that will likely be ...

DaniFoldi•3/14/23, 2:21 PM

Hello, I’m Allie!•3/14/23, 2:21 PM

I’m just wondering for having a regional coordinator, it would be nice to know “this DO is in ENAM”

Hello, I’m Allie!•3/14/23, 2:21 PM

I don’t need the exact colo, just the locationHint region

Cckoeninger oh locationHint region as opposed to the actual region an arbitary DO is running...

Hello, I’m Allie!•3/14/23, 2:22 PM

Maybe on the ID, have a location property with the region attached. Doesn’t have to be the region provided when creating the DO, just the region the DO was actually spawned in

Cckoeninger or the equivalent naming convention as locationHint, regardless of whether you g...

Hello, I’m Allie!•3/14/23, 2:24 PM

This one, I think. I don’t need it externally available, it would just be nice to have a DO be able to recognize that it spawned in North America(or whatever the region code is)

Cckoeninger what's the use case?

Hello, I’m Allie!•3/14/23, 2:26 PM

Having a regional coordinator for a group of DOs. It would allow the DOs to communicate from one region to another efficiently, without manually having to have connections to/from every DO

Hello, I’m Allie!•3/14/23, 2:27 PM

Also to apply filters to incoming messages at the regional level. Basically, a message bus, where instead of having every DO process every message, then instead have a few regional filters, that then pass to the individual DOs as necessary

I guess this was before alarms

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