Fedora and fallback DNS servers [LWN.net]

Fedora and fallback DNS servers

Posted Mar 11, 2021 6:29 UTC (Thu) by LtWorf (subscriber, #124958)
In reply to: Fedora and fallback DNS servers by jschrod
Parent article: Fedora and fallback DNS servers

> Yes, that's all important -- but for a high-school course

In italy you can sign up to any university course having done any high school. In fact most people signing up for computer science, typically will have gone to a "liceo scientifico" rather than a "tecnico industriale informatico" and will have a focus more on mathematics than network protocols.

No credit mathematics courses are offered to bring people up to speed on mathematics, but you are absolutely not expected to now the entire content of "Computer Networks by Andrew S. Tanenbaum" before you can even apply.

I can't really understand how learning about networks or computer architecture or operating systems makes it impossible to understand scientific papers. Does it make sense to talk about distributed algorithms without knowing how it all works and why a certain set of assumptions is made for the proof?

I also have no idea what you mean college vs university.

Is image manipulation computer science? Can it be mentioned that jpg saves more green information because camera sensors are built this way, because we see green better? Or is that out of topic and forbidden?

I guess you are limiting "computer science" to what you learnt in your university and are excluding anything else as not relevant.

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Fedora and fallback DNS servers

Posted Mar 11, 2021 14:02 UTC (Thu) by farnz (subscriber, #17727) [Link] (3 responses)

The distinction between Computer Engineering (which is the application of Computer Science to real world problems) and Computer Science (which is all about the theory) is common in many countries. Some places do mix the two together, and call the resulting mixture Computer Science, but that is by no means the common outcome.

In Computer Engineering, you will absolutely have to deal with practical things like tcpdump, TCP handshake, DNS, Ethernet frame structure and more

In Computer Science, you're looking at algorithms and how computation can be done usefully with them. So, for example, you will make certain assumptions about a distributed world, and those assumptions will be backed either by some handwaving about how a Computer Engineer can build a real system that meets those assumptions or by referencing some work by a Computer Engineer that shows that these assumptions are valid given a system that has been built.

To give an example of how this separates out; a Computer Scientist will make some assumptions about how routers in a network could be made to work (messages passed to neighbouring routers, neighbours forward packets towards their destination, there is a time delay between sending a packet and its reception), and look at how you could guarantee that packets go through the network to their destination efficiently. If they pull in Dijkstra's SPF algorithm, they'll describe something that works a lot like OSPF, but without all the little practicalities that make OSPF work in real networks.

In contrast, a computer engineer will look at things like the reliability of multicast, practical packet formats, MTU limitations, and build you something that works like OSPF.

It sounds to me like you have been through a system that blends Computer Engineering with Computer Science, and calls it Computer Science; this does happen in many institutions, but is not the most common case.

Fedora and fallback DNS servers

Posted Mar 11, 2021 15:21 UTC (Thu) by pizza (subscriber, #46) [Link]

> In Computer Engineering, you will absolutely have to deal with practical things like tcpdump, TCP handshake, DNS, Ethernet frame structure and more

Where I went to college [1], CompE was a specialized form of Electrical Engineering, focusing more on digital circuits and the logical building blocks that go into computer hardware. In other words, the physical layer.

Their Computer Science program was originally an offshoot of Mathematics, focused on computational theory and algorithms, although you could get quite a lot of real-world practicalities in the various specializations and electives -- and I recall one course that specifically covered the design principles behind TCP/IP, DNS, and so forth.

> It sounds to me like you have been through a system that blends Computer Engineering with Computer Science, and calls it Computer Science; this does happen in many institutions, but is not the most common case.

"The common case" is clearly not as common as one would think...

[1] Georgia Institute of Technology, widely considered to be a tier-1 STEM school in the US

Fedora and fallback DNS servers

Posted Mar 11, 2021 16:47 UTC (Thu) by excors (subscriber, #95769) [Link] (1 responses)

> If they [a computer scientist] pull in Dijkstra's SPF algorithm, they'll describe something that works a lot like OSPF, but without all the little practicalities that make OSPF work in real networks.
>
> In contrast, a computer engineer will look at things like the reliability of multicast, practical packet formats, MTU limitations, and build you something that works like OSPF.

But also the computer engineer might not realise that some of the implementation details violate the assumptions made in the mathematical proofs of Dijkstra's algorithm, so in rare edge cases their implementation fails to find a correct routing solution, and they can't understand the research paper that explains the problem precisely with six pages of algebra.

I think that's a significant challenge for Computer Science as a field - there's often a lack of connection between theory and practice. CS isn't like pure maths which can often be considered valuable in its own right; it's more like theoretical physics in that it's only successful when it gets applied to the real world. It's fine if it takes decades of speculative theoretical work before finding an application, but there should be a reasonable expectation that it will eventually find one. An unimplementable computer science concept is like an untestable physics theory - it's not really CS/physics any more, it's just an inefficient way to do maths.

But a lot of CS in academia doesn't really understand real-world computer engineering, because it's had no exposure to environments outside a university, so it fails to identify real problems that need solving; and a lot of computer engineering doesn't understand or care much about academic CS, so it keeps discovering and inventing bad fixes for problems that *have* been solved properly.

It's good for people to specialise but I think it's important to have at least some people who are comfortable with both sides, to keep them connected and working productively on the same problems. There are many cases where that is happening - see e.g. decades of programming language research which was only implemented in niche languages, while real software was written in C, but that research is now being adopted by mainstream production-quality languages thanks to people working to bridge the gap - but I suspect it's far less common than it should be.

Fedora and fallback DNS servers

Posted Mar 11, 2021 21:03 UTC (Thu) by LtWorf (subscriber, #124958) [Link]

Where I did my master, they had different research groups for more applied and more theoretical stuff.

Anyway, turned out I knew 2 people doing their thesis in 2 different research groups and it was basically the same topic. Low power algorithms, if I remember. It was years ago.

Anyway, the 2 had not met each other and had no idea that in the same building there was another person working on the same project from a different angle.