Seastar VS serenity

I used glommio as the async executor (instead of something like tokio), and it is wonderful. For people wondering whether it's "good enough" or to use C++ and seastar (as I have thought about a lot before starting this project), take the leap of faith, it's fast - both in terms of run time and to code.

b) It's proven now e.g Seastar, Glommio that the fastest way to run a multi-threaded application is to have one instance with one thread pinned per CPU core. Then to have fibers/lightweight threads on top handling all of the asynchronous code. Your approach of lots of instances is the slowest so there will be a ton of unnecessary thread context-switching.

The most common example is DPDK [1]. It's a framework for building bespoke networking stacks that are usable from userspace, without involving the kernel.

You'll find DPDK mentioned a lot in the networking/HPC/data center literature. An example of a backend framework that uses DPDK is the seastar framework [2]. Also, I recently stumbled upon a paper for efficient RPC networks in data centers [3].

If you want to learn more, the p99 conference by ScyllaDB has tons of speakers talking about some interesting challenges.

[1] https://www.dpdk.org/.

[2] https://github.com/scylladb/seastar

[3] https://github.com/erpc-io/eRPC

I assume Tokio itself, see e.g monoio or glommio, but also Seastar for C++.

https://core.dpdk.org/supported/ lists supported nics. You're best just reading material from the dpdk website for figuring out roughly what it is. It is used for a lot of different goals. For most web C++ stuff it's mainly used because you can avoid round trips of data passing through the kernel and can reference network data without tons of copying. For an example check out the SeaStar framework, https://seastar.io/, which is under the hood of ScyllaDB.

As this is a Kafka sub, this may be a good opportunity to mention that Redpanda is based on the same framework (seastar) as Scylla. The idea of sharding work to CPU cores turns out to apply very well to the Kafka data model, too!

Seastar which is a thread per core runtime written by the Scylla devs thats used in both Redpanda and Scylla as the underlying runtime. https://github.com/scylladb/seastar

ScyllaDB is, ironically, maybe one of the worst examples the author could have come up with for "abstraction" in the article.

If folks aren't familiar with their work/internal tech, go check out some of their repos like Seastar. They have some of the most talented systems programmers on the planet writing thin veneers over kernel and hardware API's to squeeze every ounce out of performance.

https://github.com/scylladb/seastar

I know it's beside the point, but I just had to share because I thought that was funny

I’ve seen frameworks for c++ (https://seastar.io/) and rust (https://github.com/actix/actix) which support what you’re describing out of the box.

If you're interested in scaling and asynchronous programming in c++ I highly recommend you investigate the SeaStar application framework. You wouldn't build a web service with SeaStar, rather you would build the infrastructure that you would use to build the web service on top of. https://github.com/scylladb/seastar

SerenityOS replicates that look and feel. It is also implemented in a dialect of C++ that adheres to some of the good parts of C++98: https://serenityos.org

One example of a useful technique

https://serenityos.org/ apparently only makes source code available. There are no binary images of the OS to install

I think Andreas said this functions like a little test -- if you're not willing to build it from source, then you probably wouldn't be a good contributor anyway.

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Likewise, my shell project provides source tarballs only, right now - https://www.oilshell.org/release/0.21.0/

It is packaged in a number of places, which I appreciate. That means some other people are willing to do some work.

And they provide good feedback.

I would like it to be more widely available, but yeah I definitely see that you need to "gate" peanut gallery feedback a bit, because it takes up a lot of time.

Of course, it's a tricky balance, because you also want feedback from casual users, to make the project better.

Indeed, given the existence of `JS::NonnullGCPtr`, `JS::GcPtr` intentionally corresponds to a nullable pointer, so it seems dangerous to convert one to a reference without a null-check.

That said, a naive code search finds what *may* be more cases of this pattern:

https://github.com/search?q=repo%3ASerenityOS%2Fserenity+%2F...

Eg: https://github.com/SerenityOS/serenity/blob/a68b134e6dea5065... -> https://github.com/SerenityOS/serenity/blob/a68b134e6dea5065...

In some of those search results, it is fine because there is a preceding null-check, and obviously I know nothing about this code other than this naive search result, but perhaps it would be prudent to vet all of them.

It is a SerenityOS project. You can find the answer to that question in their primary project's FAQ[1].

1. https://github.com/SerenityOS/serenity/blob/master/Documenta...

https://github.com/SerenityOS/serenity

The best way to write proper exception free C++ is not to use the C++ Standard Library.

I initially confused it with Serenity OS prior to watching the video: https://github.com/SerenityOS/serenity

My contributions to SerenityOS[0] helped me get my current job. My team lead (who was also my interviewer) was interested in what I did since I listed some of it in my CV, and I showed him some PRs I made and explained what went into each of them. It was really exciting because I didn't have professional experience with low-level development, and basically got the job due to hobby programming.

[0]: https://github.com/SerenityOS/serenity/pulls?q=is%3Apr+autho...

Definitely not "literally impossible", just a great deal of work. https://github.com/SerenityOS/serenity/tree/master/Ladybird