rust-libp2p VS tokio

Substrate and Lighthouse use libp2p as a networking stack for communication between nodes. The libp2p framework is a versatile modular peer-to-peer networking stack. It provides a collections of abstractions, mechanisms, and protocols for facilitating communication in P2P systems. In particular, libp2p supports multiple transport mechanisms (TCP, QUIC, WebSocket, WebTransport, etc.), encryption schemes (TLS and Noise), and stream multiplexing. Higher-level protocols in libp2p are implemented on top of reliable, ordered, bidirectional binary streams, which are transparently encrypted and multiplexed by the framework.

It's a peer-to-peer "engine" with switchable components. Seems to run on different platforms (browsers, mobile, desktop, server).

At a glance, it looks pretty much like libp2p (https://libp2p.io/) but seems to integrate with libp2p as well (meaning you should be able to use Bifrost on one end, and libp2p on the other), so I'm guessing there is at least some fundamental difference, but I cannot spot it. Seems to use slightly different terminology compared to libp2p.

ComposeDB is a graph database created by 3BoxLabs, a company well-known in the Web3 ecosystem for their work on decentralized identifiers (DIDs) and their main product the Ceramic network. Ceramic is a network of nodes that store and share composable data streams on top of libp2p, the network stack that also powers IPFS.

Yes, there is already a Rust version (https://github.com/libp2p/rust-libp2p) that behaves well at this level but I think we can reach a higher level of performance on this point with Zig. Also, if you look at the long term roadmap of libp2p (https://github.com/libp2p/specs/blob/master/ROADMAP.md), the mobile devices and IoT integrations for example are part of the considerations.

libp2p

At Filecoin Foundation, we see the technologies in the Filecoin ecosystem offering rock-steady stepping stones to this better future. Libp2p lets individual users find and talk to each other, without needing central servers. IPFS gives new services a way to find data, wherever it is stored — freeing them from dependence on one social media company over another and letting users move from one service to another. The Filecoin network itself, with incentivized storage, not only provides a provably stable basis for hosting content, but also shines a light on the kind of incentive systems that will enable independent social media to sustain and provide for itself for the long run, without relying on the largesse of the current tech giants.

Maybe https://libp2p.io

So, after rolling my eyes and saying to myself 'not another web3 protocol', I began to understand the need for something new that not only takes advantage of the cutting edge in peer to peer networking but also acknowledges the fact that the client-server architecture is also not going away (which is incredibly important in a world full of low-powered, embedded devices).

Being able to control nondeterminism is particularly useful for testing and debugging. This allows creating reproducible test environments, as well as discrete-event simulation for faster-than-real-time simulation of time delays. For example, Cardano uses a simulation environment for the IO monad that closely follows core Haskell packages; Sui has a simulator based on madsim that provides an API-compatible replacement for the Tokio runtime and intercepts various POSIX API calls in order to enforce determinism. Both allow running the same code in production as in the simulator for testing.

tokio / hyper / toml / serde / serde_json / json5 / console

tokio - An asynchronous runtime for Rust

3. Tokio

The AWS SDK makes use of the async capabilities in the Tokio library. So when you see async in front of a fn that function is capable of executing asynchronously.

Petar is also looking at implementing concurrency the way it is in Go to have a fully functional virtual machine as it is in the spec. This would likely attract more external contributors to developing the VM. One advantage of Rust is that, with the concurrency model, there is already an extensive library called Tokio which he can use. Petar stresses that this isn’t easy, but he believes it’s achievable, at least as a research topic around determinism and concurrency.

Another thing to point out is that async is a thing in Rust. I'm not going to begin to dive into this paradigm in this article, but know it's handled by the awesome Tokio framework.

So I started by using Tokio, a popular async runtime. The docs and samples helped me get a simple outbound TCP connection working. The Rust async book also had a lot of good explanations, both practical and digging into the details of what a runtime does.

Regarding the quote:

> The Original Sin of Rust async programming is making it multi-threaded by default. If premature optimization is the root of all evil, this is the mother of all premature optimizations, and it curses all your code with the unholy Send + 'static, or worse yet Send + Sync + 'static, which just kills all the joy of actually writing Rust.

Agree about the melodramatic tone. I also don't think removing the Send + Sync really makes that big a difference. It's the 'static that bothers me the most. I want scoped concurrency. Something like <https://github.com/tokio-rs/tokio/issues/2596>.

Another thing I really hate about Rust async right now is the poor instrumentation. I'm having a production problem at work right now in which some tasks just get stuck. I wish I could do the equivalent of `gdb; thread apply all bt`. Looking forward to <https://github.com/tokio-rs/tokio/issues/5638> landing at least. It exists right now but is experimental and in my experience sometimes panics. I'm actually writing a PR today to at least use the experimental version on SIGTERM to see what's going on, on the theory that if it crashes oh well, we're shutting down anyway.

Neither of these complaints would be addressed by taking away work stealing. In fact, I could keep doing down my list, and taking away work stealing wouldn't really help with much of anything.

The PHP <-> Rust bindings are provided by https://github.com/Nicelocal/ext-php-rs/ (our fork of https://github.com/davidcole1340/ext-php-rs with a bunch of UX improvements :).

php-tokio's integrates the https://revolt.run event loop with the https://tokio.rs event loop; async functionality is provided by the two event loops, in combination with PHP fibers through revolt's suspension API (I could've directly used the PHP Fiber API to provide coroutine suspension, but it was a tad easier with revolt's suspension API (https://revolt.run/fibers), since it also handles the base case of suspension in the main fiber).