Show HN: Pumpkin – A Modern Minecraft server written in Rust

Hello. I recently developed Pumpkin, Its a efficent and fast Minecraft server completely written in Rust from the ground up, Check it out :D

> What Pumpkin will not

> Be a drop-in replacement for vanilla or other servers

It seems to me that unless it's a drop-in replacement its not a Minecraft server? Akin to how say an Uno deck isn't a drop-in replacement for a Hearts deck but still both card games but not both Uno decks.

Or is it just meaning that Pumpkin (besides the network) do things differently than vanilla and so you might not be able to open a vanilla created world using Pumpkin?

Cool! Would be interesting to understand how to multithreading works? Is it just the "easy" parts or actual operations related to the world as well?

Similar projects:

- Feather (Rust, abandoned) https://github.com/feather-rs/feather

- Valence (Rust) https://github.com/valence-rs/valence

- Cuberite (C++) https://github.com/cuberite/cuberite

Love the idea. Especially as a learning example. Always fun to learn a language by implementing a popular game.

Am confused by these two lines. Maybe it is just difference between the 'goal' and the 'current state'.

Goal:

"Compatibility: Supports the latest Minecraft server version and adheres to vanilla game mechanics. "

But NOT:

"Be a drop-in replacement for vanilla or other servers "

Will it be a replacement for Vanilla or not?

Reminded me of this existing https://dayssincelastrustmcserver.com/

this person is going gods work

Are there any benchmarks for it? How much faster is it than a vanilla server?

I know Minecraft servers tend to get extremely resource intensive as the player count creep and people run extremely beefy servers to handle the load and still offer poor TPS.

Compatibility: refers to the ability for client of the latest mincraft server version to be able to connect to the server (pumpkin) unmodified with all mechanics working.

Drop-in replacement: refer to the ability of a server operator to simply exchange the current installation/executable of the server (be vanilla, paper, cuberite, etc...) for pumpkin while maintaining data, configuration, scripts and mods installed.

edit: grammar

Are you sharding the main thread into regions (ie. Like paper folia) or is this just breaking of non block-entities to their own threads.

The common problem with Minecraft server implementations is that they are not bug-for-bug compatible, which will lead to certain techniques (especially redstone contraptions) breaking. The technical Minecraft community depends on many implementation details which not all servers support

This looks great! Can't wait to check out the code in detail.

Tell you the truth, that doesn't help clarify to me much.

If it is compatible, then can't I 'drop it in'.

They sound like they are saying the same thing.

It is compatible so clients can connect to the server and be fully operational, and thus, I should be able to drop in this server, and use it as a server?

How can it be compatible if it doesn't maintain data, configuration, etc..

Edit: or is this about Pumpkin files. Pumpkin will maintain it's own files, data, configuration. So it can't just use existing Minecraft data files.

So if it was a new world, Pumpkin would generate new pumpkin formatted files. But couldn't just 'drop it in' on an existing world and use the existing Minecraft data files.

Not sure of long term viability as far as effort, but if it is files, couldn't a converter from MineCraft to Pumpkin file structure, make the server 'drop in'?

It has now been 0 days since a new minecraft server was written in Rust https://dayssincelastrustmcserver.com/

Pumpkin is already on that list.

Drop-in means replacing an existing thing with a new one without changing anything.

This is not compatible with other servers plugins/data/configurations, so just replacing the binary and expecting to continue where you left off is not possible.

This weeks Minecraft server! Nice!

looks good

I would say that Minecraft servers by some qualities are really hard to implement (for example generate world as Java would - using Java's random number generator to generate exactly the same world in Rust) or even impossible. But other usages, like walking through existing world with 1000 of your colleagues might be worth of writing a very fast but not a "drop in replacement" server. Or a massive minigame maybe?

Compatible: You start a Pumpkin server, vanilla clients can join and play.

Drop-in: You run a server for some time. You decide to switch the software by replacing the executable. Everything works as before.

Maybe some more concrete examples may help:

* nginx is not a drop in replacement for apache

But from a client perspective, both implement HTTP/1.1.

* podman is not a drop in replacement for docker

But from a client perspective connecting to a service hosted in docker, that connection can still occur over TCP.

On the other hand:

* pkgconf is a drop in replacement for pkg-config

* cronie is a drop in replacement for vixie-cron

"Drop-in" is what enterprise software calls "bug-for-bug compatible" - e.g., replacing RedHat with CentOS (RIP) should work exactly the same, even if the CentOS team found bugs - they report them upstream and do NOT fix them themselves, because code may be relying on the bugs.

This is especially true with complicated vanilla Minecraft setups and red stone machines (Java Minecraft red stone has "bugs" that "shouldn't be there" but cannot be removed now since so much depends on it).

But the world generation is already deterministic with seeds

In addition to the hundreds of blocks and mobs that would need to be implemented properly and rarely are, the lack of mod support is a killer.

The only "complete" reimplementation of Java Minecraft that I'm aware of is Bedrock.

Far from it. The versions lack a lot of parity and Bedrock is called "bugrock" by the community for a reason

It's pretty funny how many of these are "Is it a Minecraft server? No. It's a framework with which you can build your own rewrite of Minecraft server."

Hey, With Compatibility i mean be compatible with existing Minecraft vanilla client's and also use vanilla logic. With "Be a drop-in replacement for vanilla or other servers" i mean that if you just replace the existing server file with pumpkin, pumpkin will not load configs/plugins from vanilla/other servers

thank you :3

I would love to hear some feedback, tried my best so code is clean :D

i wish minecraft was open source, i'd be able to fix their inefficient protocol

What does "modern" mean in this context?

I edited in scare quotes for "complete" to make that clearer, but I mean in terms of at least having matching blocks/mobs despite many differing details.

Its written from the ground up and has a clean foundation (which is not the case in vanilla minecraft server code). We also want to use cool modern features like multi-threading or the rust language which is a modern language designed to fix mistakes from older languages

Downvoter, go check this: https://wiki.vg/Protocol, let me know if that's a good way to sync a lot of fast moving entities across a TCP network

This is why people struggle with their servers, not because the game was written in java

"Modern" seems to be used a loose adjective these days for "I rewrote $thing [in Rust]". Minecraft was created in 2011, and is Wikipedia says the last version of the 'classic' edition was released in 2017. So anything after 2017 is now defunct.

I don't mind people rewriting things in <insert-name-of-tech-I-like> but "modern" as a value seems pretty loose, and it's often at least arguable whether it's objectively better!

See also https://github.com/valence-rs/valence A "clean room" implementation of the Minecraft server written in Rust

"But from a client perspective, both implement HTTP/1.1."

This seems too low level example to apply for Minecraft.

Minecraft has a lot going on, back and forth. For something to be 'compatible' it would need to be so detailed an implementation of the server, that it could potentially also be a 'drop in'.

“Modern” more usually means some new JavaScript thing. In JS land, they consider anything that hasn’t had a commit on main branch in over 3 days to be a dead old project in need of being replaced with something new and “modern” that is up to date with the latest trends and breaking changes from the previous 24 hours of their world.

Usually the hyperbolic superlative for Rust projects is “blazing fast”. Of course, any kind of benchmarks or comparisons with other implementations are completely optional. It is simply enough to “cargo init” and start hammering out code. You don’t even need to consider the characteristics of the algorithms you choose to use! If it’s Rust, it’s “blazing fast”.

Guess this gets to my other point.

By the time you are 'compatible' then you have implemented everything needed to also be a 'drop-in' but data file formats might need a conversion.

So convert from Minecraft data files to Pumpkin data files. Then it could drop in.

I was thinking it would be cool to have a Minecraft server built with Bevy, but that has also already been done: https://github.com/valence-rs/valence

This got me thinking - is Rust really the right tool for the job? And I thought, Elixir/Erlang feels like the perfect tool. Sure enough, someone did it! Great reference material for someone learning how to do things on the beam https://github.com/thecodeboss/minecraft

> cool modern features like multi-threading

Java 6 had multi-threading

As someone who knew about this project from earlier (I had even joined their discord) (currently have just deleted my discord account for better state of mind) Its really made me happy that hackernews really liked this project (140 upvotes is pretty good in my opinion)

From what I remember , there was one other server as well which also was written in rust but I am not exactly sure

Also , the last time I was at it , it was really really alpha software but it was getting developed at good rate , so I am not sure about its current state (I was there when the author had gone to take his exams IIRC)

I read this in the most satirical way possible like as if a godly narrator said it calmly.

It was really funny. It felt like a Satire LMAO

yes , I was also thinking about this . +1

Minecraft has a lot of bugs or otherwise surprising behaviours that parts of the community have come to rely upon. This means that most non-vanilla minecraft servers aren't 100% drop in replacements. You have to make a decision what behaviours you want vs the performance and simplicity gains you will gain.

For example there there are tricks that allow you to delete bedrock blocks. Which then lets you either get onto the roof of the nether, or drop below the bottom of the world. Not all of these tricks will then work depending upon the specific minecraft server.

Another example is that in vanilla you can "bomb" people with experience orbs, the sheer number of orbs on the screen will grind their game to a halt since there are too many objects to track and render. Some minecraft servers work around this by grouping up experience orbs into a single bigger orb. That way you have fewer orbs on screen at once.

Lmao it is funny how we have daysinceX websites. is there a list of all such websites of daysinceXofY like dayssincelatestframeworkofnode I guess?

Minecraft Server (Zig) https://github.com/regenerativep/zig-mc-server

Where's that meme of the guy painting demons then laying down on the floor in fear when you need it.

Hey, Your lucky, i just made benchmarks all this time :D. Check them out https://snowiiii.github.io/Pumpkin/about/benchmarks.html

Hi, Valence is a framework (similar to Minestom in Java). You have to build everything you self. Pumpkin is not a framework :D. Also Valence is bit unactive (look commits)

There are no bugs in Minecraft, only features that have yet to be fully documented.

Hey, Sorry Im not native english speaker, I will try to fix all grammer issues now thanks :D

The limitation isn't the Java version, it's the way the MC code was architected.

Iirc part of original Minecraft's performance limitations were high object create/destroy rate leading to lots of garbage collection. With that in mind, picking a non-GCd language isn't completely crazy.

While Java does, the Minecraft server architecture does not.

Your most starred repo is inferior to a shell one-liner lol. Talk about pot calling the kettle black. Just use the system dict, shuf, grep, and head.

It’s bad form to badmouth someone’s earnest work for sure. I wouldn’t do it normally since I think it’s nice that you actually did something. But if you’re going to sit in a glass house and throw stones you should expect some back.

Fortunately, my house is an underground burrow so I can throw stones with impunity. As ugly as it is to do.

> i mean that if you just replace the existing server file with pumpkin, pumpkin will not load configs/plugins from vanilla/other servers

Will it ever though? Is this a goal?

Curious what protocol you would use, or how you would do it differently? Are there small enhancements to the existing protocol you would do? Genuine open question for the sake of learning.

Sorry, I may should not used the term Modern, Lets say the foundation is newer and more optimized than from the Original Minecraft server. Mojang developers have strict deadlines and do not care about performance (like basicly any big Studio today). This results in bad ugly code which only purpose it is to work nothing more. Minecraft was created 2009 btw

I will give it a try, Thanks for this project. The performance of pure vanilla server jar is so bad. Thats one thing I wish mojang would improve. I know new chunk generation is multithread at least. I also wish they'd officially support some basic control for SMP servers. Something as basic as areas defined by two corner coordinates and basic permissions like place, break, interact. Just a basic config file is fine I can manage the requests/updates ot it using other tools - or a simple commandline utilities in game to ops. Something that lets me not have to always only use an excluse whitelist. I know Paper/waterfall and the others have plugsins for this but theres just something nice about staying pure vanilla. Ive been keep servers alive for a long time now.

I would prefer the UDP Protocol over TCP like in Bedrock edition. Im pretty sure many PVP players would love this. Here is much non sense in the Minecraft protocol and things made to work not to be optimized (deadlines). At our discord we even already have a sticker :mojang_nonsense: which will be used quiet often. I also don't understand Mojang's tactic with packet changes, It sometimes looks like they care about Packets not being broken and being backwards compatible but them sometimes they change the whole Networking system (1.20)

The performance differences look pretty impressive from the benchmarks. I do notice that world generation and saving features are missing though, and these tend to be pretty expensive operations. Chunk gen especially can bring a weaker VPS to its knees. I'm sure the benchmarks were taken at an idle state, but I'd be curious to see how it compares once those features are included and being used.

I don't see it listed, but is there support for block breaking/placing yet? Presumably this would require light recalculation and a chunk update on the server.

Finally, do you plan to add advanced features like scoreboard, teams, or command block parsing in general? Mojang has at least open-sourced Brigadier for that.

Cool project. Hope to see it mature to the point of making servers easier to run on low-end hardware.

Hi. Im so happy there are so many people liking the project, The Project is still pretty WIP but im really working hard on this, i finished my exmans last week and currently in holidays so commits are again back to normal :D

I literally said Holy Shit out loud. This is an incredible improvement, and I'll refer to this in the future when I'm asked if we should make something new in Java.

I'd argue they care about performance, but they also care about a whole slew of other things that also require prioritization to maintain the game and its cottage industry. Not a huge fan of the constant dogging on mojang everyone loves to engage in...

Yes but also consider the extensibility accessibility Java gave us. EVERYONE was building Minecraft mods back in the beta days. I might go as far as to say that extensibility is what made Minecraft so great.

Hey. Im impressed with the benchmarks myself tbh.

Yep block placing and breaking is already supported, but light currently don't so everything is dark :/, We are working on it. Yep, We want to add all cool features like scoreboards, teams and we already have a API which is similar to use to Brigadier for our Commands.

Thanks, I would love to give players on low-end hardware the possibility to host servers. I think i may test Pumpkin on a raspberry PI or something one day

Maybe it's cuberite? written in C I believe

I was suprised myself thats its that bad. Well optimized binary is that what your CPU loves not a big JVM runtime

I think they are being sarcastic because the vanilla Minecraft server is heavily single threaded.

People seem to forget that if you already know where the finish line is, the journey on getting there can be made quicker and more efficient.

This, at least in my experience, applies greatly to software and hardware.

Hey, Im happy you want to try it out just keep in mind its not done yet many features are missing, We want to have all the things you listed be configurable in a config file, so i think you will like it. If you have any problems may worth to take a look at https://snowiiii.github.io/Pumpkin/troubleshooting/common_is... or just ask for help on our discord, Have fun :D

Currently Pumpkin has not much multi-threading but we want to go all in. There is already a good structure for multi-threading, We want to make everything multi-threaded what benefits from it

I remember Notch talking about the lighting calculations being one of the hardest parts to program, so I can understand that being a challenge.

Mojang made large improvements to the lighting engine in 1.20, bringing it in line with the performance mods Phosphor[1] and Starlight[2]. Despite being deprecated now, they might still offer some useful insight into how to approach such a system in a performant way. You'll need to be mindful of the licenses, but it's likely easier than reverse-engineering Minecraft (even with mappings).

[1] https://github.com/CaffeineMC/phosphor-fabric

[2] https://github.com/PaperMC/Starlight

Will definitely take a look at this, Thank you. Im btw studied the Minecraft code already so i often use the decompiled code as reference.

Please, just use one measurement unit across all measurements for easier comparison (i.e. RAM in MB, time in ms).

Wow. Pumpkin's runtime is way better (faster, much less RAM used) than the Java versions. Congrats.

I wonder what the Kotlin-based Minestom is doing differently that causes it to have numbers between Pumpkin and the Java versions.

For comparison's sake, do you have build times for Pumpkin? I'll assume that's where critics may target.

omfg haha.

How does this compare to Dragonfly (IIUC, basically the same thing, but in Go)? https://github.com/df-mc/dragonfly

It was the other way around: say, the original code as written by Notch had functions like setPosition(x,y,z) and it was okay. When Jeb got in charge, he said "it's not object-oriented enough" and rewrote everything to setPosition(position). And boom, 1GB/sec allocations...

Just to be clear this sever only works with the current vanilla version of Minecraft? I've been interested in playing again, but on the older Beta builds (1.7.3) prior to the full release versions. These versions aren't supported are they?

This looks like its for java while dragonfly seems to be for bedrock

No doubt about it. I don't think Minecraft would have gotten as far as fast in the public consciousness without content creators like Yogscast being able to produce so much novel content from modded Minecraft.

> a shell one-liner lol

Dig a little deeper in the repos and you may eventually find that this is exactly what that started as :^)

> badmouth someone’s earnest work for sure

Was speaking generally. Not meant at OP. I think it’s awesome that they are making a Minecraft server in Rust.

> Talk about pot calling the kettle black

Of course! Anything else would be bad form.

> my house is an underground burrow so I can throw stones with impunity

Sneaky, sneaky ;)

One bug abuse that blew my mind recently is the ability to have wireless redstone in vanilla [1]. I fell deep into that rabbit hole after a previous post on here about Bad Apple in Minecraft [2].

[1] https://www.youtube.com/watch?v=FLynwXDnETI [2] https://news.ycombinator.com/item?id=41798369

Your right

Haha fair play if you’re in the “we’re all clowns here” camp.

Chunk gen makes sense to implement last or never. If you want a performant Minecraft server you need to pregen all the chunks anyway. You can still later regen chunks that have never been visited to get new chunkgen on updates since chunks store the inhabited time.

I think Minecraft server re-implementations are pretty neat and I like to see when a new one comes out. There are also specific purpose server impls like MCHPRS for doing fast redstone compilation for technical minecraft.

Keeping in mind that this server appears to implement only a tiny subset of the features the ones it is benchmarked against do... No lighting, mob spawning, mob ai, redstone functionality, tree or plant growth, water/lava flow, etc.

Just waiting for Minecraft to be so reverse engineered as to be its own protocol with multiple server and client implementations that just work.

What I always found surprising was how many minecraft mods there were despite mojang having absolutely no mod support for the game.

After learning that to make a minecraft mod the process was basically decompile minecraft fight the terrible names provided by the decompiler to make your changes then recompile it, I lost all interest.

If you need to separately convert files yourself, then it is by definition not drop in

it already is, the entire protocol is reverse engineered, there are tools to automatically deobfuscate the code and there is already a full reimplementation of minecraft that also supports servers

Yarn[1] has pretty much fixed this along with fabric.

[1] https://github.com/FabricMC/yarn

Didn't really mean 'myself'. But if Pumpkin detects an existing world, and does the conversion to their own format. Then it is drop-in.

Even if they supply a tool, isn't it drop-in.

Otherwise I'd so no software in existence is really drop-in. Most of them have some update that has to happen.

How horrifying!

Does that mean there are open source clients that can connect to servers without a microsoft account?

When it comes to game servers, especially for highly modified games like minecraft, there's the client facing side, including how the game behaves, and then there's the server administration side.

If I were to interpret the statement made here I would assume that not-a-drop-in while being vanilla compliant means things like:

* It won't support server side mods without you re-writing them in rust

* It won't support bukkit plugins without you re-writing them in rust

* It doesn't support the configuration file format that the java server uses

* Maybe it doesn't support the world file format (which would be server side only)

* Maybe it doesn't support the same administrative commands (which you would only see as an administrator)

etc.

So it can definitely be compatible from the client perspective while being woefully incompatible with any prior experience anyone running a minecraft server might have.

the client has to authenticate with a central server and present a ticket to the server it wants to connect to. otherwise clients could impersonate each other easily.

That's why I said "clean room implementation". Any reason why Pumpkin does not build on top of Valence? Would be great to see a more cohesive ecosystem for Minecraft servers in the rust community rather than reinventing the wheel

thank you for your service

If that's the case, how come nobody seems to be writing improved Minecraft clients?

Ever since I started playing it in the beta days I've been frustrated with how poorly Minecraft performs relative to what it's showing on the screen. (Not that that stopped me from pouring hundreds of hours into the damn thing.)

Yeah, it was always weird how 32x32x48 extreme reactors lagged the game whenever you looked at them, but the moment you looked away everything was fine.

> "modern" as a value seems pretty loose, and it's often at least arguable whether it's objectively better!

Well, there is research on this!

https://security.googleblog.com/2024/09/eliminating-memory-s... writes:

> vulnerabilities decay exponentially. They have a half-life. [...] A large-scale study of vulnerability lifetimes² published in 2022 in Usenix Security confirmed this phenomenon. Researchers found that the vast majority of vulnerabilities reside in new or recently modified code

Where ² goes to https://www.usenix.org/conference/usenixsecurity22/presentat...

A study limitation is that they looked only at security-relevant bugs (vulnerabilities). As someone who writes code, I would tend to think that this also goes for bugs without a direct security impact, but I don't have the data to back that notion up

Basically any significant Java software uses disproportionate amounts of RAM. My server can easily run a web server, database server, ftp server, memory cache, etc., times a few copies because various containers have their own web server or whatnot, all at the same time. But a single copy of Minecraft is too much, even when everything else is shut down.

That's why I struggle with the server: it's written in Java. Other game servers don't seem to have this problem. If the network protocol were all, that'd be great

(I didn't downvote any of your posts in case you now wonder if that was me)

These wouldn’t significantly affect the first 10 chunks loaded?

Feels kinda obvious to me? As time goes on bug density can only go on direction, and making no changes to a codebase certainly doesn’t make it go up.

How do you throw stones out of an underground burrow?

A lot of the parity issues are due to Bedrock not reimplementing bugs from Java (quasi-connectivity aka "droppers are doors".)

Huh, if this exists and there’s already so many servers, maybe I should build a client instead.

Hilarious site but a little unjustified. Out of those, only Valence is a real "this already exists" argument. There's 7 total and the first 3 are dead and the latest 3 (incl pumpkin) are all 2024. And all of the 2024 ones explicitly differentiate themselves from Valence which is more of a framework that focuses on modularity. These latest 3 all look like healthy competitors that are all amicable towards each other

  |          | released | stars | last_update |
  |----------|----------|-------|-------------|
  | feather  | 19aug    | 2,614 | 2 years ago |
  | mchprs   | 20jun    | 1,632 | last month  |
  | graphite | 22jun    | 160   | 2 years ago |
  | valence  | 22sep    | 2,731 | 3 days ago  |
  | hyperion | 24mar    | 361   | today       |
  | pumpkin  | 24jul    | 965   | today       |
  | ferrumc  | 24sep    | 673   | today       |

You should check out minetest. Being renamed to luanti