osv VS c2rust

I've been looking at a few.

https://github.com/cloudius-systems/osv

https://ops.city/ (also nanovms) - this is one that I actually got working to at least demo state

I have also found OSv to be interesting.

https://osv.io/

Wow, just now seeing this topic. I work for a cloud company hosted in AWS. We started out, Netflix/Spotify style microservices. We were all on ec2 images generate by packer (and later with AWS Image Factory). When Docker hit, we kicked the tires but never did anything with it beyond using it for running unit tests, and later, infrastructure tests. 5 years ago, during a hackathon, our little group began experimenting with Unikernels, or library operating systems. Interestingly enough, these Unikernels were all stripped down BSD kernels. OSv is FreeBSD based, and Rumprun is NetBSD based. Services running in EC2 on Unikernels would spin up and start sending and receiving traffic before the AWS EC2 healthchecks completed. They are blazing fast! Only problem in 2017, was the tooling. It would have taken too much effort to use Unikernals with our infrastructure. As soon as they start making Unikernels that can run Java bytecode like native code, the fate of containerization will be sealed, IMO. We could get basic JVM webservers running on OSv, but not Cassandra, not Kafka, not yet. OSv now runs on Firecracker, but I have not tried it out, yet. Some links if you are interested: OSv: https://osv.io Rumprun: https://github.com/rumpkernel/rumprun We used this tooling during the Hackathon, but doesn't look like it has been touched in 3 years: https://github.com/solo-io/unik Unikraft Unikernel Dev kit: https://unikraft.org/ And don't forget Firecracker running in Kubernetes https://www.weave.works/oss/firekube/ And of course, being a FreeBSD subreddit, let's not forget FreeBSD on Firecracker https://www.daemonology.net/blog/2022-10-18-FreeBSD-Firecracker.html

Whats the difference to OSv?

https://github.com/cloudius-systems/osv

OSv Unikernel — Optimizing Guest OS to Run Stateless and Serverless Apps in the Cloud — Waldek Kozaczuk [OSv Committer] Unikernels have been demonstrated to deliver excellent performance in terms of throughput and latency, while providing high isolation. However they have also been shown to underperform in some types of workloads when compared to a generic OS like Linux. In this presentation, we demonstrate that certain types of workloads - web servers, microservices, and other stateless and/or serverless apps - can greatly benefit from OSv optimized networking stack and other features. We describe number of experiments where OSv outperforms Linux guest: most notably we note 1.6 throughput (req/s) and 0.6 latency improvement (at p99 percentile) when running nginx and 1.7 throughput (req/s) and 0.6 latency improvement (at p99 percentile) when running simple microservice implemented in Golang. We also show that OSv' small kernel, low boot time and memory consumption allow for very high density when running server-less workloads. The experiment described in this presentation shows we can boot 1,800 OSv microVMs per second on AWS c5n.metal machine with 72 CPUs (25 boots/sec on single CPU) with guest boot time recorded as low as 8.98ms at p50 and 31.49ms at p99 percentile respectively. Lastly we also demonstrate how to automate the build process of the OSv kernel tailored exactly to the specific app and/or VMM so that only the code and symbols needed are part of the kernel and nothing more. OSv is an open source project and can be found at https://github.com/cloudius-systems/osv.

I guess you could have a JVM like that, but not OpenJDK. There is, however, a unikernel that supports running itself and OpenJDK in the same process: http://osv.io/

> Oracle used to offer an installation mode like this

Oracle, and BEA before them, used to offer a JVM which ran on top of a thin custom OS designed only to host the JVM, you could call it a "unikernel". Product was called JRockit Virtual Edition (JRVE), WebLogic Server Virtual Edition (WLS-VE, when used to run WebLogic), earlier BEA called it LiquidVM. The internal name for that thin custom OS was in fact "Bare Metal". Similar in concept to https://github.com/cloudius-systems/osv but completely different implementation

I think one thing which caused a problem for it, is a lot of customers want to deploy various management tools to their VMs (security auditing software, performance monitoring software, etc) and when your VM runs a custom OS that becomes very difficult or impossible. So adopting this product could lead to the pain of having to ask for exceptions to policies requiring those tools and then defending the decision to adopt it against those who use those policies to argue against it. I think this is part of why the product was discontinued.

Nowadays, Oracle offers "bare metal servers" [1] – which are just hypervisor-less servers, same as other cloud vendors do. Or similarly, "Oracle Database Appliance Bare Metal System" [2] – which just means not installing a hypervisor on your Oracle Database Appliance.

So Oracle seems to have a history of using the phrase "bare metal" in both the senses being discussed here.

[1] https://www.oracle.com/cloud/compute/bare-metal.html

[2] https://docs.oracle.com/en/engineered-systems/oracle-databas...

A recent practical example of the former: the fish shell re-wrote incrementally from C++ to Rust, and is almost finished https://github.com/fish-shell/fish-shell/discussions/10123

An example of the latter: c2rust, which is a work in progress but is very impressive https://github.com/immunant/c2rust

It currently translates into unsafe Rust, but the strategy is to separate the "compile C to unsafe Rust" steps and the "compile unsafe Rust to safe Rust" steps. As I see it, as it makes the overall task simpler, allows for more user freedom, and makes the latter potentially useful even for non-transpiled code. https://immunant.com/blog/2023/03/lifting/

But not all transpilers are between languages where at least one of them is designed to be transpiled. For example, c2rust can transpile, as the name suggests, C to (ugly, unsafe) Rust. A while ago there was a Java -> C compiler in GCC (GCJ), but it's pretty out of date now.

I do not know about your specific issue but you may be interested by https://github.com/immunant/c2rust

You should also consider using C2Rust (they're even working on C -> safe Rust translation)

> The date at the bottom of the article is 2022-06-13. Has there been further progress?

The article links to their github repo:

https://github.com/immunant/c2rust

There's commits in the last hour, so at least some signal of life.

This is arguably already the state of things.

Rust might get compiled down through MIR, down through LLVM IR, down to assembly or wasm... which then might be JIT or AOT (re)compiled into other bytecodes... which might perhaps be decompiled back up to C... and C might be retranslated back to horrific unsafe-spamming Rust by the likes of https://c2rust.com/. We've come full circle!

The main issue is that retranslating high level languages into other high level languages isn't something that there's actually a lot of demand for, especially commercially, especially given the N x M translation matrix going on. So a lot of the projects "stabilize" (get abandoned). And automatically translating between the idioms of those languages gets even nastier in terms of matrix bloat.

Well, you've got stuff like MSIL and JVM bytecodes which are higher level, and preserve more type information, and can be compiled to / decompiled from while still preserving more structure, but they still form competing incompatible ecosystems.

That's the wrong direction. What's needed are intelligent converters which convert less-strict languages to more-strict ones.

Non-intelligent converters just make a mess. Here's c2rust.[1]

Classic C++ to modern C++, plus a compiler flag to lock out all the old unsafe stuff, would be an achievement.

[1] https://c2rust.com/

Well, technically, it's not hard to build such data structures. If you are willing to liberally use raw pointers, UnsafeCell, MaybeUninit and ManuallyDrop, then you can more-or-less write C-equivalent code in unsafe Rust. (there are even transpilers from C to Rust)

/uj This transpiles from C to unsafe Rust using an existing tool, then strips the unsafe keyword from the generated function signatures