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I find it difficult to believe that the team that built the prototype for http/2 (SPDY), implemented it for chrome, tested it on gazillions of customers around the world, wasn't bothered to talk to anyone who did networking.

Sure you can argue that the tradeoffs they selected were the wrong tradeoffs and that they may have been biased by their narrow domain specific goals (reducing latency to render an average web page). Perhaps they thought that people with really horrible packet loss will just fallback to http or use amp or whatever.

But I cannot believe that the mistakes were caused by them just not being aware of how networks work or, worse, failing to talk with somebody that did

SPDY's header compression allowed cookies to be easily leaked. This vulnerability was well known at the time so had they even asked an intern at Google Zero to look at it they would have been immediately schooled.

https://bugzilla.mozilla.org/show_bug.cgi?id=779413

In their performance tests vs HTTP 1.1 the team simulated loading many top websites, but presumably by accident used a single TCP connection for SPDY across the entire test suite (this was visible in their screenshots of Chrome's network panel, no connection time for SPDY).

They also never tested SPDY against pipelining - but Microsoft did and found pipelining performed the same. SPDY's benefit was merely a cleaner, less messy equivalent of pipelining.

So I think it's fair to say these developers were not the best Google had to offer.

another explanation - they did test it in other scenarios but the results were against their hopes so they 'accidentally' omitted such tests in the 'official' test suite. Very common tactic, you massage your data until you get what you want.

> But I cannot believe that the mistakes were caused by them just not being aware of how networks work or, worse, failing to talk with somebody that did

As someone who was part of the rollout of HTTP2 for a $large_website, I can confirm that "this will harm mobile performance" was outright and flatly rejected. This included people who were our reps on the w3c. I just had to sit there and wait for the real world metrics to come in

"multiplexing will remove bottlenecks!"

"benchmarks prove that its faster!"

"you just don't understand how TCP works"

"the people at google are very smart, what do you know?"

"server push will reduce latency"

etc etc etc.

We even had the graphs of page size over time (going ever up) and average usable bandwidth (not keeping up, especially on mobile) None of that mattered until the rollout had a real world effect on our performance.

So what was that real world effect?

5-25% increase in loadtime (median), which caused a drop off in ongoing activity. Users also complained.

It doesn't matter. You can provide the numbers when asked by the proponents of HTTP2/3 'do you have proof of your claim??', they will just turn around and say your real world data is not valid or that they need peer-reviewed article in Science.

> (...) they will just turn around and say your real world data is not valid or that they need peer-reviewed article in Science.

This sounds like a bullshit conspiratorial excuse. If you have real world data and you aren't afraid of having peers looking through it, nothing prevents you from presenting it to peers.

So where is that data?

Instead, you just have vague unsupported unbelievable claims made by random people in the internet, as if that's any way to decide over policy, and any faint doubt raised over that claim is faced with conspiratorial remarks complemented by statements on how everyone around OP is incompetent except him.

I will go as far as to claim OP's assertion is unbelievable, to the point of sounding like bullshit. It's entirely unbelievable that people designing protocols for a multinational corporation whose bread and butter is stuff done over TCP connections were oblivious to how TCP works, and the most incompetent of them would bother to design the first major revision of HTTP. Unbelievable.

But hey, some random guy online said something, so it must be true!

I should have made clear that this is mobile performance. Desktop performance was broadly good

Seeing early QUIC development not account for the DDoS potential of choosing UDP makes it pretty clear that networking is not top-of-mind.

Are you saying there's ddos potential because UDP itself doesn't have a connection handshake? There's still one on top of UDP. The initial packet could be forged, but so could one from TCP (a SYN flood).

SYN flood cookies are probably older than me at this point

HTTP/1.1 (RFC2616) specified a limit of two connections per server, which most browsers initially interpreted to mean per-origin, which still lead to quite a lot of unnecessary blocking. I think browsers eventually decided to increase that to 6, but as evidenced by viewing the "Network" tab of the Developer Tools on a lot of modern pages, it is in fact not very uncommon anymore to have a substantially larger number of resources per origin.

While it's true that HTTP/2 can be worse than HTTP/1.1, I don't think it usually is; it's pretty easy to demonstrate just how much better HTTP/2 is over a typical Internet connection. SPDY and HTTP/2 were clearly better and rarely worse, whereas HTTP/3 is almost never worse (maybe when interplay with TCP rate control is poor?) On very unreliable and very high latency connections it can definitely go the other way, but statistically my experience is that a large majority of cases see an improvement on plain-old HTTP/2.

That said, for all of the complexity HTTP/2 adds, it is kind of a nice protocol. I like that all of the "special" parts of the HTTP/1.1 request and response were just turned into header fields. HPACK is a minor pain in the ass, but it is pretty efficient. You get multiple concurrent bidirectional streams per connection and they can each send headers/trailers. There's even the MASQUE protocol, which enables unreliable datagrams with HTTP/3. Put together this makes HTTP/2 and HTTP/3 amazingly versatile protocols that you can really use for all kinds of shit, which makes sense given the legacy of HTTP/1.1.

There are some pitfalls even still. For example, all of this added complexity has made life a bit harder for load balancing and middleboxes. TCP level load balancing or round robin is basically defeated by using HTTP/2 multiplexing, without the client being explicitly cautious of this.

This limit is completely artificial. Let's limit HTTP/2 to maximum 6 multiplexed streams per connection and see how it fares with HTTP1.1 with 6 TCP connections to the server. All of sudden HTTP1.1 wins :)

Have you got any data to backup that claim?

It’s also a specious argument anyway. The six connection limit isn’t purely artificial, opening and tracking TCP connection state is expensive, and happens entirely in the kernel. There’s a very real cap on how many TCP connections a machine can serve before the kernel starts barfing, and that cap is substantially lower than the number of multiplexed streams you can push over a single TCP connection.

You’re also completely ignoring TCP slow start process, which you can bet your bottom dollar will prevent six TCP streams beating six multiplexed streams over a single TCP stream when measuring latency from first connection.

Yes I do have data. You can have that data, too. Just do the testing yourself.

You’re making the claims, feel free to share the data you already have.

Oh and while doing that, also feel free to respond to the rest of comment that outlines why opening an unbounded number of TCP connections to a server might be a bad idea.

I'm sure it can. However in my real world use cases, HTTP/2 and 3 work better when available for me, so I'm glad to have them. I'm sure this comes as no surprise to most people since SPDY went through a lot of testing before becoming HTTP/2, but just because it doesn't win on every point of the graph does not mean it doesn't still win overall.

Besides that, more than half my point is that I like HTTP/2 and HTTP/3 for the featureset, and you can't get that by increasing the max connection limit for HTTP/1.1.

That would greatly limit the maximum number of simultaneous clients behind the same IP (at the office, at the university etc)

When the limit is reached, all clients would be broken

Looks like a good deal indeed, why do not we do that

> That's not really head of line blocking, because in HTTP1.1 you'd just open up another connection.

All browsers cap the number of connections which are opened to a single domain (I think on IE this was 4, and has increased to 10, but it's not a large number).

you are correct, but with keepalive, 10 connections over http1 will beat 1 connection over http2[1] even 4 connections will do better.

[1] when there is high latency, or some packet loss, and the requests are batched evenly over all connections.

Each of those connections needs its own TCP and TLS handshake making a total of 6 trips. Also, although this didn't take off, h2 had push promise which could have been a big help.

Yeah HTTP/2 push is so great that Chrome removed it. Straight from the horse mouth: "However, it was problematic as Jake Archibald wrote about previously, and the performance benefits were often difficult to realize" https://developer.chrome.com/blog/removing-push

> This is Top of line blocking and was entirely predictable had the HTTP2 team bothered to talk to anyone who did networking. > > Its part of the reason why I was greatly suspicious of QUIC, because it appeared like it was designed by the same people that thought http2 was a good idea.

Agreed - i've always found them to be living in a world of their own, which doesn't match the realities of actual networking out there.

In fact, the very same team after touting QUIC over UDP as the revolutionary protocol is now complaining that the real world realities aren't matching their expectations and so are now proposing to do QUIC over TCP. Here's that proposal https://mailarchive.ietf.org/arch/msg/quic/N82WBOa_RJIb4cPQw...

One thing in favor of QUIC is that it had a lot of other people also working on it, not just the HTTP2 team. People like Daniel Stenberg who have worked in networking for ages and are not beholden to the incentive structures at Google.

According to his Wikipedia page he was also on the working group for HTTP2

HTTP/2 works quite well in practice though, both in browsers and for custom RPC protocols. Certainly better than HTTP/1.1.

It works well on desktop. On mobile it really performs badly. especially if you are doing interactive things and lazy loading.

It is imposible to meaningfuly evaluate these different protocols against each other without considering the "use case". For example, if someone is requesting 100 pages from a site, all hosted on the same domain, and nothing else,1 then HTTP/1.1 is the best of the three. The requests can be sent over a single connection. HOL blocking is not an issue. I have tested this exhaustively outside the browser for over a decade. (People promoting HTTP/2 and HTTP/3, and HN commenters submitting snarky replies every time I mention the utility of HTTP/1.1 pipelining, apparently have not tested this at all.)

1. This is text retrieval. The www is not a handful of browsers controlled by companies that seek to profit from advertising. It was and still is a facility that provides for (hyper)text retrieval.

HTTP/2 and HTTP/3 come from an advertising commpany and a CDN that expect ads hosted on different domains in every page. That is what _they_ want. Is that want _www users_ want. We do not know because www users were never asked. We do know that www users do not like ads. When given the choice, they say, "No."

The advertising company keeps repeating this HOL blocking as a problem of HTTP/1.1, and now it gets parroted everywhere, and few even know what it means. HOL blocking is not a problem if the www user is not requesting ads and tracking from different domains. How many www users actually want to request ads and tracking and particpate in telemetry. The so-called "tech" company might try to argue that all of them do, or more commonly that, "They do not care." Meanwhile its own employees call ad blocking a "right of passage" (direct quote from a reply I got on HN).

The truth is that when evaluating these new HTTP protocols, it matters what the www user is trying to do. Many users are simply trying to retrieve information as text. But the advertising company believes that www users only want to do what is in the interest of the advertising company: let the advertising company's browser automatically send requests for ads, tracking and telemetry purposes. (Except for employees of so-called "tech" companies profiting from the sale of online ad services. They exempted and are free to block the ads and tracking.)

> entirely predictable had the HTTP2 team bothered to talk to anyone who did networking

I think it's good that things have evolved rather than being stuck behind naysaying. Sure, there were pitfalls/hurdles that could have been avoided, but it's not clear that maintaining perfection every step of the way would have got us to QUIC.

This is not some pitfall. This is a major problem in tech and IMHO totally unacceptable. The same things are re-invented all over again and again without actually making much of an improvement.

The result of this is that we get constant upgrades and "improvements", but overall reliability, UI usability, latency and performance in general are actually worsening every year.

> overall reliability, UI usability, latency and performance

is this just a rose-tinted gut feel, or do you have actual data?

Reliability: Gut feeling. I'm a support engineer. The modern DevOps/Cloud stack is just garbage. People only believe they save money with it because they don't calculate in what they will pay me.

UI usability: This is a discoverable, good UI: https://jbss.de/bilder/scr118d.gif . You can instantly tell what is a button, where you can enter text and what is inert. You can even read out all the hotkeys from the screenshot. Now, without hovering over it with your mouse, check the header of this post (the grey line) and tell me which strings will take you to a place (= are a link), which do an action (= are a button) or are inert. They all look the same and you need to investigate it first with the cursor. And even then you can't tell the buttons ("flag", "vouch") apart from the links ("parent", "context").

Latency and performance: I played RTS games for 15 years. Despite getting old and rustly, i easily hit 120 APM during office work. I can tell if an application can handle it. Things like the Windows Start menu were fast enough for me until like Vista, but now they aren't - i need to wait a bit or i click before it is popped up.

> have actual data

The CPU/GPU required to render an interface at 60hz has gone up inline with moore's law.

How about resolution? Color depth? Complexity of what is displayed?

Last I checked my old commodore PET wasn’t rendering ray-traced 4K UHD graphics at 60hz…

60hz is pretty easy if all you are doing is a simple character buffer.

> old commodore PET wasn’t rendering ray-traced 4K UHD graphics at 60hz…

Nor is my phone, yet newer apps are now struggling to render basic GUIs at 60hz.

Your phone has a higher resolution, a lower size, and a lower thermal footprint, and more battery life....

How about latency of the key press? Why Apple II has practically zero latency and your modern monster desktop is visibly lagging in a fucking text editor? Despite Apple II being literally millions times slower than a modern rig.