Email or username:

Password:

Forgot your password?
Top-level
Christine Lemmer-Webber

Things are NOT good, if I'm correct above, as we make things more decentralized in the atproto-public-shared-heap model. The more self-hosting and indeed the more "full nodes" join, the more it gets expensive for each of the nodes and the network EXPLODES!

Truly self-hosted atproto is NOT POSSIBLE!

12 comments
Christine Lemmer-Webber replied to Christine

And there is no solution to this without adding directed message passing. Another way to say this is: to fix a system like ATProto to allow for self-hosting, you have to ultimately fundamentally change it to be a lot more like a system like ActivityPub!

Christine Lemmer-Webber replied to Christine

Now I left more of the precise analytical explanation in my blogpost. But social media isn't great for that, so go check out my blogpost if you want to go through all that (eg if you're more like @dthompson and less like me, I'm a narrative person) dustycloud.org/blog/re-re-blue

Christine Lemmer-Webber replied to Christine

Here's our story:
- We have 26 users: [Alice, Bob, Carol, ... Zack].
- Each user sends one message per day, which is intended to have one recipient. (This may sound unrealistic, but it's fine for modeling.)
- Each user sends a message in a ring: Alice => Bob, Bob => Carol, ... Zack => Alice

Christine Lemmer-Webber replied to Christine

Now just before you say "wait but ATProto isn't for DMs", yes, but one way this could happen is that eg Bob follows Alice, Carol follows Bob, etc.

What I'm saying is, messages can have an "intended audience". That's what we're using here.

Christine Lemmer-Webber replied to Christine

Before we get into this, remember, the main difference between "message passing" and the "shared heap" is the former has directed and delivered messages, the latter does not. See prev blogpost for explainer.

So, what happens in a day for both systems? Because that's what we really want to find out.

Christine Lemmer-Webber replied to Christine

Under message passing, Alice sends her message to Bob. Only Bob need *receive* the message. So on and so forth.

- For an individual self-hosted node, messages passed per day: 1.
- Per the decentralized network, total messages passed zooming out: 26.

That's about what we'd expect.

Christine Lemmer-Webber replied to Christine

Under the public-gods-eye-view-shared-heap model, each user must know of all messages to know what may be relevant. Each user must *receive* all messages.
- Individual self-hosted server, 26 messages must be received per day.
- Zoom out on whole decentralized network: 26*26: 676!

Christine Lemmer-Webber replied to Christine

Sounds survivable with 26 users though, right?
Let's try just adding 5 more users.

Message passing:
- Per node per day: no change.
- Per the network: 5 more messages.

Public gods-eye-view-shared-heap-model:
- Per node per day: 5 more per day
- Per network: ((31 * 31) - (26 * 26)): 285!

Christine Lemmer-Webber replied to Christine

Now, could we handle a million self hosted users? Is it possible? No problem in message passing. EXPLOSIVE with atproto.

What if we had a million users and added just 5 more? How many more messages must the network bear?

5 new messages in message passing.
*10,000,025* new messages sent in atproto!

Christine Lemmer-Webber replied to Christine

"Christine that's ridiculous, we're not expecting a million self-hosted users"

Well I think it would be nice!

But regardless, ActivityPub has 27,000 servers on it, all meaningfully participating in the network.

ATProto, in its current design, would be crushed to DEATH

Christine Lemmer-Webber replied to Christine

"But Christine", you may say, "I heard gossip might fix this!"

No. It cannot.

In fact, I was being more generous than a gossip network, and assumed you only *received* a message once.

With gossip you might *receive* more than once.

But you need to receive a message to know it.

Christine Lemmer-Webber replied to Christine

ATProto was designed for a "big world" view. That's fine! But I'm trying to show seriously what happens if it was actually, really decentralized.

*Every* fully participating node added to the network makes the network explosively more expensive.

ATProto doesn't scale towards decentralization.

Go Up