Go HTTP2 demo | Hacker News Reader

Go HTTP2 demo

http2.golang.org

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This is actually pretty impressive!

https://http2.golang.org/gophertiles

Noticed that one too. The difference between 1s latency is huge between HTTP/1 and HTTP/2!

Where do you see 1sec latency difference?

EDIT: ok found it and it's striking, the difference is even more than 1 sec (total loading time)

The server doesn't support keep-alive, and it doesn't support pipelining. It seems to be built by design to have the worst possible performance for HTTP/1.1.

Whatever problems pipelining may or may not have, a benchmark like this one loading a bunch of small static images is what it is designed for. I can see how some small-timey Go implementation would not have an actual HTTP/1.1 server, but for Google to come out with HTTP/2 without even having tested against pipelining is just pitiful.

These Google people seem hellbent on not ever having a fair comparison.

Pretty sure the demo server supports keep-alive, just as all Go net/http servers do by default: https://github.com/bradfitz/http2/blob/master/h2demo/h2demo....

There's no "Connection: keep-alive" in the response header. If they purposely turned it off that's even worse.

That's because it's the default in HTTP 1.1. The server would need to send "Connection: close" to disable keep-alive.

Apparently "connection: keep-alive" is needed to enable pipelining in the browsers:

http://www.guypo.com/http-pipelining-big-in-mobile/

Your browser wouldn't even use pipelining if it was supported. The reason HTTP/2 exists is because pipeling ended up not being a solution.

Pipelining works fine. It's on in mobile Safari, and neither Google nor Mozilla found what software it didn't work on (so probably Superfish and other malware). If you use Firefox it's still a great way to speed up normal page loads since HTTP/2 isn't used for unencrypted data.

The comparison there had me literally jumping up and down in my seat.

Related to "Hacking with Andrew and Brad: an HTTP/2 client in Go" @ https://news.ycombinator.com/item?id=9112344

One can build a http2/SPDY demo fairly easily these days. I co-wrote a SPDY library[0] that has been used in production for streaming video across the interweb to mobile devices to great success.

There is a simple server created with the library in a few lines. Try it out.

The library was built "the Go way" with the idea to support http2 as soon as it was final and we're looking to do that soon!

[0] https://github.com/amahi/spdy/

$ curl https://http2.golang.org/ -v * Hostname was NOT found in DNS cache * Trying 130.211.116.44... * Connected to http2.golang.org (130.211.116.44) port 443 (#0)

Hangs at this point for me -- anyone else having issues?

I experienced a significant connection delay. I assume it's due to the traffic surge from HN.

Seems ok for me now-- maybe some temporary hiccup. Worth noting curl doesn't support HTTP/2, but I was experiencing the same delay in chrome w/SPDY too.

The latest version of curl does support HTTP/2, I believe.

I didn't know that HTTP2 supports streaming data. How is this done? It is not a websocket connection.

   /clockstream streams the current time every second

And why does it require ~1KB of junk to force browsers to start rendering immediately?

You can do this with HTTP1 actually. Its how motion jpeg works. I've actually got a little mjpeg php script here - https://github.com/donatj/mjpeg-php/blob/master/mjpeg.php Just flush every frame and you're golden.

I've also seen simple dashboards that do this, displaying one line at a time as data comes in, simply never closing the connection.

Some browsers will try to guess the content type from first few bytes, so they won't start showing anything until enough bytes have been received.

Well behaved browsers should not do that if Content-Type header is set.

I thought this has something to do with browsers returning their own internal 404 page if the content was less than 1kb? Something to do with that being the max size of error pages on old webservers, which browsers wanted to replace.

Yep. Here's the code from nginx: https://github.com/nginx/nginx/blob/master/src/http/ngx_http...

Thanks! I knew I read about that years and years ago but wasn't sure if it was still true.

> I didn't know that HTTP2 supports streaming data

It's not specific to HTTP2, and is in fact possible since the server doesn't send a Content-Length so the client doesn't know when the server is done. Think of it not as streaming, but as a really slow and consistent huge response. HTTP2 just makes it smoother (remember: HTTP2 doesn't change semantics, it only changes how things are represented on the wire)

Now, the way the demo server uses that is a bit rough; there is a specification for that in the form of Server-Sent events (https://developer.mozilla.org/en-US/docs/Server-sent_events/...).

The code might help: https://github.com/bradfitz/http2/blob/master/h2demo/h2demo....

Hijacking the thread: Anyone made already experiences with HTTP2, Node, Express and Nginx together?

Down for me... :/

Down for me too. I'm guessing due to load. It's also reported as being down based on an https checker [1], but I don't know if it would correctly handle http2 so this may always give a false positive.

1 = http://https.downforeveryone.com/check.php?url=http2.golang....

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