[StavrosK]

Relevant to http2 push but slightly off topic, I love how I can add a single line of code to my Django project (to include a middleware library I wrote) to have automatic http2 push. The middleware will parse the static media on the page and push them to the client, it's much faster with no effort.

The library is at https://github.com/skorokithakis/django-cloudflare-push if anyone wants to use it. It's slightly misnamed, as it supports any server that uses the Link header for push, not just CloudFlare.

[realityking]

Doesn‘t that mean I‘ll get all assets pushed to my client every time I visit any page of your site, regardless of the file‘s cache status?

That does not seem to be a good tradeoff, especially on mobile.

[StavrosK]

No, the browser cancels the download if it has the assets before they download.

[_jn]

That should take approximately as long as a client<->server ping, right? So shouldn't it be irrelevant for JS/CSS that loads within that time (say, 50Mbps & 15ms ping --> everything below 93KB gzipped?)

[StavrosK]

Yes, you'd download some things you don't need to. Last I heard, they're working on an extension so the browser can tell the server what media it has when it requests the initial page so they won't get sent at all.

[tomatsu]

You could use a cookie which contains the revision and then the server could selectively push things which have changed since then.

[majewsky]

Didn't we all have this conversation years ago already with nocache query parameters etc.? Reminds me of number 6 in RFC 1925: "It's easier to move a problem around [to another protocol layer] than to solve it."

I still don't see how HTTP/2 Push is solving any real-world problems [1] besides Google being able to push ads so that it counts as an impression even if the client blocks ads.

[1] I don't count the slightly faster initial page load since I'm getting that junk on every page load via push even if I already have it, so I'm paying with my data allowance. If you want your site to load fast, just fix your goddamn bloat.

[paulirish]

Unfortunately it doesn't. There is no mechanism right now for the browser to cancel the pushed resources. H2 Push's Cache Digest will introduce this ability, but it's still being designed.

[StavrosK]

Are you sure? SO seems to disagree:

https://stackoverflow.com/questions/29352282/does-the-browse...

And this feature shows as merged into ff56:

https://bugzilla.mozilla.org/show_bug.cgi?id=1367551

Cache digests are about the client telling the server what items it has cached so push doesn't even start, not about canceling pushes.

[codedokode]

You might better be working on caching so that the resources are loaded only the first time. Otherwise you need some way to know whether the user has the resources cached or not (a cookie maybe?).