Readit Newstlb commented on An argument for increasing TCP's initial congestion window (2024) jeclark.net/articles/tcp-... · Posted by u/cyb0rg0
This article is stuck in a very wide valley of being perhaps somewhat familiar with the domain concepts but nowhere near deep enough to draw any of the conclusions being drawn. It is close enough to being completely wrong.
The primary tradeoff of initcwnd is setting a reasonable window before you've learned anything about the path. BBR has little say on this because it takes, in relative terms, quite a while to go through its phases. An early BBR session is therefore not really superior to other congestion controls because that is not the problem it is really focused on.
Jacking up the initcwnd, you start to risk tail loss, which is the worst kind of loss for a sliding window.. especially in the primordial connection. There are ways of trying to deal with all that but they are loss predictions.
If you are a big enough operator, maybe you have some a priori knowledge to jack this up for certain situations. But people are also reckless and do not understand the tradeoffs or overall fairness that the transport community tries to achieve.
As other comments have pointed out, QUIC stacks also replicate congestion control and other algorithms based on the TCP RFCs. These are usually much simpler and lacking features compared to the mainline Linux TCP stack. It's not a free lunch and doesn't obviate the problem space any transport protocol has to make tradeoffs on.
Google has probably sent data to almost every /24 in the last hour. Probably 99% of their egress data goes to destinations where they've sent enough data recently to make a good estimate of bottleneck link speed and queue size.
Having to pick a particular initcwnd to be used for every new TCP connection is an architectural limitation. If they could collect data about each destination and start each TCP connection with a congestion window based on the recent history of transfers from any of their servers to that destination, it could be much better.
It's not a trivial problem to collect bandwidth and buffer size estimates and provide them to every server without delaying the connection, but it would be fun to build such a system.
tlb commented on Is the interstellar object 3I/ATLAS alien technology? [pdf] lweb.cfa.harvard.edu/~loe... · Posted by u/jackbravo
He is the boy who cried wolf at this point. Every interstellar object is (oops I mean could be) alien artefact.
Also he raised a bunch of funds to dig one up under the ocean and got nothing.
When and if alien life is discovered, there’s a high chance the discoverer will be someone who’s spent their career searching for it, rather than someone just stumbling across ironclad proof one fine day.
I’m inclined to let those searchers speculate in public. If society’s rule is that you can’t even speculate about X until you have proof, it will hold back science significantly. History has many such examples of forbidden speculation leading to long delays.
tlb commented on Why do LLMs still not run code before giving it to you? · Posted by u/highfrequency
Is it a common use case to produce a standalone program that could be tested in isolation? Usually I'm asking for a function (or just a few lines of change) that depends on the rest of my code & environment, so it's not trivial to test.
tlb commented on Every satellite orbiting earth and who owns them (2023) dewesoft.com/blog/every-s... · Posted by u/jonbaer
Somebody has never heard of the tragedy of the commons. https://en.m.wikipedia.org/wiki/Tragedy_of_the_commons
> The tragedy of the commons is the concept that, if many people enjoy unfettered access to a finite, valuable resource, such as a pasture, they will tend to overuse it and may end up destroying its value altogether. Even if some users exercised voluntary restraint, the other users would merely replace them, the predictable result being a "tragedy" for all.
There is no right of absolute freedom, because at some point that freedom affects other people who also have rights. So we're always limited explicitly and implicitly in what we can do. Free, unfettered access just means taking something away from somebody else.
Space is the one resource that isn't finite. And even in LEO, the amount of space is huge. It's about the same surface area of the earth, but tens of kilometers thick.
We used to have to leave a lot of space between satellites because their orbits varied unpredictably, but we've gotten better at packing them.
Someday we'll talk about the days of 5000 satellites like we talk about when computers had 4096 bytes of RAM, and it will be fine.
Please downvote or flag such comments (but only flag if you're fairly sure.)
tlb commented on Ask HN: Help me navigate a PIP at a remote startup in the Netherlands · Posted by u/msoad
There are lots of reasons why people don't fit at a company, and only some of them are the employee's fault. But whose fault it is doesn't really matter. If you aren't happy and aren't appreciated, you should be out interviewing for better jobs. Somewhere there's a position where you'll be both happy and appreciated.
tlb commented on When Is WebAssembly Going to Get DOM Support? queue.acm.org/detail.cfm?... · Posted by u/jazzypants
With access to DOM it could run with no (or just very little) js, no ts-to-js transpiler, no web-framework-of-the-month wobbly frontends perpetually reinventing the wheel. One could use a sane language for the frontend. That would be quite the revolution.
You can just interpolate bits of Javascript inside C++ to access the DOM, like so:
#include <emscripten.h>
void sayHello()
{
EM_ASM(
let foo = document.getElementById('foo')
foo.innerHTML = 'hello';
);
}
tlb commented on When Is WebAssembly Going to Get DOM Support? queue.acm.org/detail.cfm?... · Posted by u/jazzypants
Give me one thing that your theoretical WASM can "revolutionize". Aside from more efficient covert crypto mining on shady sites.
I use it for a web version of some robotics simulation & visualization software I wrote in C++. It normally runs on as an app on Mac or Linux, but compiling to WASM lets me show public interactive demos.
Before WASM, the options were:
- require everyone to install an app to see visualizations
- just show canned videos of visualizations
- write and maintain a parallel Javascript version
Demo at https://throbol.com/sheet/examples/humanoid_walking.tb
How have they advertised that? Was it clock frequency? Their mitigations mean it still runs at that clock frequency.