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by neftaly 898 days ago
R2 was used because it was the only database-like service CF offered at the time.

IIRC the P2pcf client polls the worker for new peers. Pubsub would let you use an ongoing websockets connection, plus all the channel management logic is built-in. The game-changer is that they've said they'll charge per-message as opposed to per-connection-second, unlike everyone else!
2 comments
vlovich123 898 days ago
That’s not true though. DO/D2 are database as well (DO precedes R2 and D2 overlapped). KV is an eventually consistent database.

DO/D2 will likely perform better than R2 unless you’re storing everything in the metadata. KV will perform better than all of them although if the storage is to keep a list of peers the API as exists today won’t work well for that - you’ll have to do 1 key per connection and retrieve via a paged list - otherwise you can lose clients since KV has no mechanism to do durable updates of values stored within keys*. You could also do DO with background refresh of cache to maintain good performance while maintaining better bounds on how long a value stays in the cache.

* actually it is possible if you mediate updates to KV through a DO (with storage as the ground truth or without it and risk occasional lost writes if the CF infrastructure decides to kill and reset/relocate your DO).

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neftaly 897 days ago
Fair enough, I didn't investigate them very far, as IMO only pubsub maps to the "webrtc signalling for misers" problem neatly enough to make it worth adopting (probably -- they haven't actually said how much it will cost).
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gfodor 897 days ago
At the time I wrote this library using websockets on Cloudflare would have been prohibitively expensive compared to this polling method. Has that changed?
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neftaly 897 days ago
From my understanding, yes. I asked about the billing model on the CF Discord 6-12? months ago. I don't know how much it costs per message, or if there is a catch wrt cheap wrtc signalling, however my understanding is that you won't be paying per user or per hour etc. To be clear this is through their MQTT 5.0 service only.
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kentonv 897 days ago
Yes, in the last year Durable Objects introduced "hibernation", in which the server object can shut down with WebSocket connections still active, to be started back up when a new message arrives. This largely solves cost issues with WebSockets on Workers / DO.
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gfodor 897 days ago
Yeah this might be a better solution now for sure.
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neftaly 896 days ago
I think it'll work pretty well! I might keep something cloud portable cooking away in the background.
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