blueboat VS gvisor

Right now it is an exciting time for JavaScript. We just got a new shiny fast runtime Bun, with the last new kid Deno being released only 4 years ago, and we have edge computing/serverless runtimes like Cloudflare worker and Blueboat. With all these hypes for the JavaScript community, I could not help but ask, how come only JavaScript gets all these fancy new runtimes? Why don’t we hear these more often in other languages?

Hello HN! I'm building mvsqlite, a distributed variant of SQLite with MVCC transactions, that runs on FoundationDB. It is a drop-in replacement that just needs an `LD_PRELOAD` for existing applications using SQLite.

I made this because [Blueboat](https://github.com/losfair/blueboat) needs a native SQL interface to persistent data. Apparently, just providing a transactional key-value store isn’t enough - it is more easy and efficient to build complex business logic on an SQL database, and it seems necessary to bring a self-hostable distributed SQL DB onto the platform. Since FoundationDB is Blueboat’s only stateful external dependency, I decided to build the SQL capabilities on top of it.

At its core, mvsqlite’s storage engine, mvstore, is a multi-version page store built on FoundationDB. It addresses the duration and size limits (5 secs, 10 MB) of FDB transactions, by handling multi-versioning itself. Pages are fully versioned, so they are always snapshot-readable in the future. An SQLite transaction fetches the read version during `BEGIN TRANSACTION`, and this version is used as the per-page range scan upper bound in future page read requests.

For writes, pages are first written to a content-addressed store keyed by the page's hash. At commit, hashes of each written page in the SQLite transaction is written to the page index in a single FDB transaction to preserve atomicity. With 8K pages and ~60B per key-value entry in the page index, each SQLite transaction can be as large as 1.3 GB (compared to FDB's native txn size limit of 10 MB).

mvsqlite is not yet "production-ready", since it hasn’t received enough testing, and I may still have a few changes to make to the on-disk format. But please ask here if you have any questions!

This sounds quite a bit like Cloudflare Workers, and they have a comparison page - https://github.com/losfair/blueboat/wiki/Comparison-with-Clo....

> If one writes Go or Rust, there are much better ways to run them than targeting WASM

wasm has its place, especially for contained workloads that can be wrapped in its strict capability boundaries (think, file-encoding jobs that shouldn't access anything else but said files: https://news.ycombinator.com/item?id=29112713).

> Containers are still the defacto standard.

wasmedge [0], atmo [1], krustlet [2], blueboat [3] and numerous other projects are turning up the heat [4]!

[0] https://github.com/WasmEdge/WasmEdge

[1] https://github.com/suborbital/atmo

[2] https://github.com/krustlet/krustlet

[3] https://github.com/losfair/blueboat

[4] https://news.ycombinator.com/item?id=30155295

Isn't gVisor kind of this as well?

"gVisor is an application kernel for containers. It limits the host kernel surface accessible to the application while still giving the application access to all the features it expects. Unlike most kernels, gVisor does not assume or require a fixed set of physical resources; instead, it leverages existing host kernel functionality and runs as a normal process. In other words, gVisor implements Linux by way of Linux."

https://github.com/google/gvisor

This sort of feels like seeing someone riding a bike and saying: why don’t they just get a car? The simple fact is that containers and VMs are quite different. Whether something uses VMX and friends or not is also a red herring, as gVisor also “rolls it own VMM” [1].

[1] https://github.com/google/gvisor/tree/master/pkg/sentry/plat...

There's two major production-ready Go-based operating system(-ish) projects:

- Google's gVisor[1] (a re-implementation of a significant subset of the Linux syscall ABI for isolation, also mentioned in the article)

- USBArmory's Tamago[2] (a single-threaded bare-metal Go runtime for SOCs)

Both of these are security-focused with a clear trade off: sacrifice some performance for memory safe and excellent readability (and auditability). I feel like that's the sweet spot for low-level Go - projects that need memory safety but would rather trade some performance for simplicity.

[1]: https://github.com/google/gvisor

[2]: https://github.com/usbarmory/tamago

It uses gVisor to create a TCP/IP stack in userspace, and starts a wireguard interface on it, which the HTTP server from http.Serve listens on. The library will print a URL after startup, where you can access your server. You can create multiple listeners in one binary.

The playground compiles the program with GOOS=linux, GOARCH=amd64 and runs the program with gVisor. Detailed documentation is available at the gVisor site.

You could use a container sandbox like gVisor, light virtual machines as containers (Kata containers, firecracker + containerd) or full virtual machines (virtlet as a CRI).