How Decentralized Is Bluesky Really? https://dustycloud.org/blog/how-decentralized-is-bluesky/

A technical deep-dive, since people have been asking me for my thoughts. I'll expand a bit on some of the key points here in a thread. 🧵

First of all, before I say anything else, my goal here is NOT to be mean to Bluesky's devs. I know there's a lot of fediverse-Bluesky rivalry, but I have enormous respect for Jay Graber and her team and I know they believe in their vision!

This started because I got some very kind encouragement by @bnewbold to write something. I'm trying to be technical in my analysis, not unkind. I hope that can be recognized, really and truly.

That said, let's get to the summary: Bluesky / ATProto are not decentralized or federated, according to my analysis.

However, the "credible exit" goal is worth perusing, and does use decentralization techniques! But it is not decentralization/federation without moving the goalposts on those terms.

Furthermore, I think Bluesky is providing something valuable: a lot of people are trying to leave X-Twitter *right now* because it has become a completely toxic place.

The fact that Bluesky's team has managed to scale to receive such users is incredible, nearly feeling miraculous.

On the fediverse we also see a lot of accusations of Bluesky being owned by Jack Dorsey, and this isn't true. My understanding is that Jay performed an impressive amount of negotiation to allow Bluesky to receive funding independently.

These days Jack Dorsey is instead focusing on Nostr, which I can only describe as "a sequel to Secure Scuttlebutt with extremely bad vibes where bitcoin people talk about bitcoin"

I participated a bit in the process of when Bluesky was Jack Dorsey and Parag Agrawal's personal project. I also believe Jack and Parag were sincere about Bluesky as a decentralized social network protocol that Twitter would adopt, which is the directive that Bluesky was given as an organization.

When Jay Graber was awarded the position to lead Bluesky, I was not surprised. To me, Jay was the obvious choice to deliver what Bluesky was being directed, and I do think Jay is an excellent leader

There is also something which Bluesky gets right which the fediverse does not. I mentioned that Bluesky uses decentralization *techniques*, and the most important of those is content-addressing. This allows content to exist even when a server goes down.

This is a great decision and I have advocated that the fediverse do so as well. In fact several years ago I wrote a demo in @spritely's early days showing off how one could build a content-addressed ActivityPub in a spec-compatible way.

So I have opened here with the things that Bluesky does well. As you may guess, we are about to move into critiques territory, and it's a lot of critiques from a *decentralization*/*federation* perspective. It doesn't erase the "credible exit" goals, which I think are good still.

Let's dive in...

A frequent way of describing Bluesky's decentralization, including by Bluesky's team, is "it's like a bunch of blogs (Personal Data Stores), and then the relay/appview/etc pieces are like search engines"

This is a reasonable starting point for thinking about things, so let's run with it.

In fact ATProto's own tutorial even says "Think of our app like a Google": https://atproto.com/guides/applications

And indeed this is a good way to think about things. But it doesn't seem so bad, because we have Personal Data Stores like blogs, so probably things are fine, right?

While most people would argue that blogs and websites are open, few would argue that *Google* is open. So this is a curious place to begin thinking, and yet structually, it is actually quite apt.

PDS'es are like blogs, the rest is like Google. But relays/appviews/etc do a lot *more* than Google.

Relays, AppViews, etc don't just index information. Blogs and their interactions are generally slow-moving, but social media is direct and responsive. Notifications and fast interactions are key. So search engines, yes, but we should also think of these components of doing much more.

But let's stay on this blog/search engine analogy for a while before we unpack what it means on a *technical* level, which is interesting. Let's analyze for the moment from a power dynamics level.

Building a web search engine is actually pretty easy these days, you can do so with off-the-shelf tools. And yet there are only a couple of search engines *really*, Google and Bing (DDG mostly uses Bing). And yet the information is right there. *Anyone* could run their own engine. Why don't they?

Furthermore there is an interesting connection between blogs and social media: the death of blogs + feed aggregation directly aligns with the death of social media.

How many of you were around for the birth and awkward death of blog engine feeds? Because I was! Oh, remember Google Reader?

Feed readers are also simple, and in fact they were even easy to self host, even on the desktop! But Google Reader came in and was such a good design that everyone used it.

When it went away, blogs were still *there*. But blogging as a *syndication medium* died. One big player left, and it's gone.

This was sad for me especially; my favorite medium on the internet ever was webcomics. Webcomics still exist, sort of, but the loss of independent publishing and aggregation meant that they had to change to survive.

The shape of webcomics started to get shaped to the shape of Twitter's image box.

This may seem like an enormous aside, but it isn't. The big sell currently is that "you don't need to run a relay because you can run your own PDS!" but as I have illustrated here, the distribution and syndication power dynamics matter a lot.

So. It isn't enough to self-host your own PDS. Whether or not people can run their own relays/appviews/etc actually matters *a lot* if we want this stuff to survive.

So, can we? How hard is it to run your own AppView/Relay/etc?

Today, there is only one real organization running a Relay that really matters or an AppView that people use for anything other than fun aggregation of statistics. Nothing that resembles meaningful decentralization of the network. It's all run by one company: Bluesky.

But could we change that?

People are trying; most notably alice has done some great work recently: https://alice.bsky.sh/post/3laega7icmi2q

So now someone *can* run their own Relay (not the AppView yet, but maybe soon), and we're getting a sense of the cost and scale. This is good news; we didn't know before.

In fact we also have an idea of the rate of growth. Approximately 4 months prior, @bnewbold.net posted an article detailing how to run a Bluesky relay: https://whtwnd.com/bnewbold.net/entries/Notes%20on%20Running%20a%20Full-Network%20atproto%20Relay%20(July%202024)

This is great. We need more people trying to do so to get a sense of how decentralized things can be.

Just focusing on storage, in July @bnewbold.net estimated the amount of storage expected to run a Bluesky relay is approx 1 terabyte. In just 4 months at start of this month (November), alice estimates nearly 5 terabytes.

This is a fast growth rate and this is *before* the big post-election influx.

I tried estimating how much this would cost; as a lazy approximation I dumped a 5 terabyte machine into seeing what Linode would cost to self-host, and it was approximately 55k a year: https://bsky.app/profile/dustyweb.bsky.social/post/3lah5n3kld42q

That's a lazy estimate, but that's also what many people make in the US every year

However @bnewbold.net pointed out, correctly!, that there were cheaper options available. If we used even Linode's block storage, it would be cheaper (but still expensive) for the storage component, and this is true https://bsky.app/profile/dustyweb.bsky.social/post/3lah5n3kld42q

In fact @bnewbold and alice had gotten the server down to just close to $200/month in their estimate, much much cheaper than I had, by choosing a dedicated server plan. Much cheaper!

But there's a problem though; that's cheap because you've got a server that has a dedicated disk...

Even if we look at the dedicated hosting provider that @bnewbold provided in June and scale the cost to the pre-election storage requirements, we are adding on a massive amount of cost every month, over $400/month more.

But worse, we have reached the limits of what is possible to do with a dedicated server. We *have to* move to abstracted storage from this point forward because we're starting to hit the limits of what's offered for cheap dedicated storage on one machine. And this number will only grow, and as said previously, is growing at an enormous rate.

I have spent a lot of time focusing on the cost of storage, but storage is only one cost required. These estimates have been done so far against servers that *nobody is actually using*. The cost of servers that people are using will be much higher, because more needs to happen than just store things.

And that is not even to mention the challenges with administrating, dealing with takedown requests, illegal content, etc, which are probably much more serious.

Let's take a break, the analysis of server costs is boring and I don't like doing it, and I'm sure people will throw numbers at me of the absolute race-to-the-bottom hosting numbers they can find to store and run all this stuff, but really that's not interesting to me.

Let's do a comparison.

Remember that the idea of "fully self-hosting" on Bluesky/ATProto at this point is primarily abstract; nobody is really doing it. But of course there's a place where tens of thousands of people are running their own servers for millions of users, and that's the fediverse/ActivityPub.

As said, tens of thousands of people are self-hosting *today*. Fediverse software doesn't just scale up, it scales *down*.

GotoSocial is cheap enough on resources where you can run it for family and friends on a raspberry pi or spare laptop you have sitting around.

Now you're hitting the point in this thread where some of you may be thinking "aha! this is where Christine is saying that the fediverse/activitypub are awesome and atproto is terrible!"

you have NO IDEA HOW MUCH I CRITICIZE THE FEDIVERSE ALL THE TIME, I do it all the time, and will later here

The fediverse has a lot of flaws. Oh trust me, we're gonna get to that.

But comparison-wise: what I mean to say is that architectural decisions matter, and scaling up isn't the only thing that's important, *scaling down matters too*.

If you care about decentralization, anyway.