[puffyvolvo]

abstractions layers exist for this reason. as much of a sham as the 7-layer networking model is, it's the reason you can spin up an http server without knowing tcp internals, and you can write a webapp without caring (much) about if its being served over https, http/2, or SPDY.

[lanstin]

I would make a big distinction between 'without knowing' and "without worrying about." Software productivity is directly proportional to the amount of the system you can ignore while you are writing the code at hand. But not knowing how stuff works makes you less of an engineer and more of a artist. Cause and effect and reason are key tools, and not knowing about TCP handshake or windows just makes it difficult to figure out how to answer fundamental questions about how your code works. It means things will be forever mysterious to you, or interesting in the sense of biology where you gather a lot of data rather than mathematics where pure thought can give you immense power.

[jimbokun]

To be an engineer, you need the ability to dive deeper into these abstractions when necessary, while most of the time you can just not think about them.

Quickly getting up to speed on something you don't know yet is probably the single most critical skill to be a good engineer.

[dweekly]

All true. The problems start getting gnarly when Something goes Wrong in the magic black box powering your service. That neat framework that made it trivial to spin up an HTTP/2 endpoint is emitting headers that your CDN doesn't like and now suddenly you're 14 stack layers deep in a new codebase written in a language that may not be your forte...

[ohgodplsno]

While I wouldn't judge someone not knowing anything about layer 1 or 2, knowing something about MTUs, traffic congestion, routing is something that should be taught at any basic level of CS school. Not caring if it's served over http2? Why the hell would you? Write your software to take advantage of the platform it's on, and the stack beneath it. The simple fact of using http2 might change your organisation from one fat file served from a CDN, into many that load in parallel and quicker. By not caring about this, you just... waste it all to make yet another shitty-performing webapp. In the same way, I don't ask you to know the TCP protocol by heart, but knowing just basics means you can open up wireshark and debug things.

Once again: if you don't know your stack, you're just wasting performance everywhere, and you're just a code plumber.

[puffyvolvo]

> knowing something about MTUs

isn't that why MTU discovery exists?

> Write your software to take advantage of the platform it's on, and the stack beneath it

sure, but usually those bits are usually abstracted away still. otherwise cross-compatability or migrating to a different stack becomes a massive pain.

> The simple fact of using http2 might change your organisation from one fat file served from a CDN, into many that load in parallel and quicker.

others have pointed out things like h2push specifically, that was kind of what i meant with the "(much)" in my original comment. Even then with something like nginx supporting server-push on its end, whatever its fronting could effectively be http/2 unaware and still reap some of the benefits. I imagine it wont be long before there are smarter methods to transparently support this stuff.

[exdsq]

But this does matter to web developers! For example http/2 lets you request multiple files at once and server push support. If you don't know this you might not implement it and end up with subpar performance. http/3 is going to be built on UDP-based Quic and won't even support http://, will need a `Alt-Svc:` header, and removes the http/2 prioritisation stuff.

God knows how a UDP-based http is going to work but these are considerations a 'Software Engineer' who works on web systems should think about.

[kaba0]

Someone writing the framework should absolutely be intimately familiar with it, and should work on making these new capabilities easy to use from a higher level where your typical web dev can make use of it without much thought, if any.

[cjalmeida]

Err, no. Look at most startups and tell me how many of them care if they’re serving optimized content over HTTP/2?