8 ms·

Nginx HTTP/2 server push support

189 points by x25519 9y ago

jbergstroem 9y ago
I've recently spent more time using H2O over nginx, mainly because of its more complete support of HTTP 2 (push, cache-aware push, ..) but also out of the box support for brotli compression and mruby (think lua landscape for nginx). Even though nginx made it easier to build and ship third party modules separately, I feel like the module community (as well as distro maintainers/packagers) haven't followed suit. There's obviously pre-baked packages like openresty which has lua world, but then there's no brotli.
- youngtaff 9y ago
  With you on that one - h2o is a lovely server
- sureaboutthis 9y ago
  My web dev company now has a few small clients on h2o for the same reasons. It gives us a chance to try h2o out without any downfall. Still very early but loving it.
- SahAssar 9y ago
  The nginx brotli module is very easy to build, I usually build my openresty with brotli and nchan as add in modules and have never encountered any issues.
- vbtechguy 9y ago
  been using ngx_brotli with my Centmin Mod Nginx stack for what seems like years now https://community.centminmod.com/threads/how-to-use-brotli-compression-for-centmin-mod-nginx-web-servers.10688/ https://community.centminmod.com/threads/how-to-use-brotli-c... :)
  - jbergstroem 9y ago
    The upstream repo from google hasn't been updated in over a year; issues are being opened questioning maintainership. It additionally breaks against more recent version combos of nginx/brotli. There's an active fork here (which I also use on my remaining nginx instances) https://github.com/eustas/ngx_brotli https://github.com/eustas/ngx_brotli
    - vbtechguy 9y ago
      yup i am using eustas fork for ngx_brotli works well :)
x25519 9y ago
They did a static analysis and fixed a null pointer dereference here: https://hg.nginx.org/nginx/rev/8b0553239592 https://hg.nginx.org/nginx/rev/8b0553239592
- jchb 9y ago
  They might want to consider using clang nullability annotations (_Nullable etc) when compiling on clang. Can use a macro so it becomes a noop when the compiler does not support it. The static analyser would then get a lot of more information to work with, and it also serves as a kind of documentation.
alwillis 9y ago
Glad push support is finally about to ship.
seanwilson 9y ago
Are there any good general guidelines on when you should use HTTP2 push? Edit: Oops, I missed out "push" at the end.
- ryantownsend 9y ago
  You might want to read https://jakearchibald.com/2017/h2-push-tougher-than-i-thought/ https://jakearchibald.com/2017/h2-push-tougher-than-i-though... This is specific to H2 Push
  - seanwilson 9y ago
    Yes, I read a few articles like this and it doesn't seem clear when you should use HTTP2 push.
- crishoj 9y ago
  I would suggest using HTTP/2 whenever possible. Features like connection multiplexing and pipelining alone are huge benefits.
  - smartbit 9y ago
    Research by Homaan Behesti of Fastly (above at https://news.ycombinator.com/item?id=16365413#16365605 https://news.ycombinator.com/item?id=16365413#16365605) suggest that you test h2 with your site and see how h2 compares to h1.
- eicnix 9y ago
  According to [0] you can gain performance improvements pretty much in every scenario. [0] https://docs.google.com/presentation/d/1r7QXGYOLCh4fcUq0jDdDwKJWNqWK1o4xMtYpKZCJYjM/present?slide=id.p19 https://docs.google.com/presentation/d/1r7QXGYOLCh4fcUq0jDdD...
  - niklasrde 9y ago
    With some exceptions, we found: https://medium.com/bbc-design-engineering/http-2-is-easy-just-turn-it-on-34baad2d1fb1 https://medium.com/bbc-design-engineering/http-2-is-easy-jus...
nodesocket 9y ago
Awesome. Is this going to make it into stable 1.12.X?
- x25519 9y ago
  No, new features don't usually get backported to the stable branch. It will ship with 1.13.9 (mainline) in 6 hours (at the time of writing). For stable branch, you need to wait until the 1.13 milestone is completed, which according to their roadmap (https://trac.nginx.org/nginx/milestone/1.13 https://trac.nginx.org/nginx/milestone/1.13) will be completed in 8 weeks.
- spectrox 9y ago
  It should be shipped with 1.13.9 according to the roadmap: https://trac.nginx.org/nginx/roadmap https://trac.nginx.org/nginx/roadmap
carlosvega 9y ago
Interesting video about HTTP 2. https://www.youtube.com/watch?v=0yzJAKknE_k https://www.youtube.com/watch?v=0yzJAKknE_k
- smartbit 9y ago
  Excellent talk & speaker, slides https://www.slideshare.net/Fastly/http2-what-no-one-is-telling-you https://www.slideshare.net/Fastly/http2-what-no-one-is-telli... Follow up talk Revisiting HTTP/2 given Jan 31, 2018 https://www.youtube.com/watch?v=wR1gF5Lhcq0 https://www.youtube.com/watch?v=wR1gF5Lhcq0 & slides https://www.slideshare.net/Fastly/revisiting-http2-87148462 https://www.slideshare.net/Fastly/revisiting-http2-87148462
ubercow 9y ago
How are you going to signal nginx what to push? Are you going to be able to push stuff from your application if using Nginx as a proxy? For example, a dynamic view that includes a css file hosted by nginx.
- rictic 9y ago
  Quoting the OP: > Also, preload links from the Link response headers, as described in https://www.w3.org/TR/preload/#server-push-http-2 https://www.w3.org/TR/preload/#server-push-http-2, can be pushed, if enabled with the "http2_push_preload" directive. So you send down some headers in your response which tells the proxy server resources it should push. Pretty elegant, and fails gracefully. I believe this is the same mechanism as other http2 servers.
deleted 9y ago
[deleted]
Mojah 9y ago
For those interested, I wrote a lengthy blogpost about HTTP/2 a few years ago, detailing the architectural/infrastructure changes needed to support it for your endusers: https://ma.ttias.be/architecting-websites-http2-era/ https://ma.ttias.be/architecting-websites-http2-era/
therealmarv 9y ago
Can somebody explain in simple words what HTTP/2 push means? Example?
- detaro 9y ago
  Browser: "Hey server, send me index.html please" Server: "Sure, here is index.html and you'll need style.css as well, so here is a second stream with that"
- moviuro 9y ago
  Client: may I get /index.html please? Server: sure, here's index.html, theme.css, and jquery.js. Client: hey wait! I didn't ask for... oh, nvm, good call. Now I can display all this without asking you for anything else. EDIT: See this: https://youtu.be/0yzJAKknE_k?t=30m52s https://youtu.be/0yzJAKknE_k?t=30m52s for more details
  - abricot 9y ago
    And add-track.js, flash-banner.gif?
    - janfoeh 9y ago
      This is just fancy cache-prewarming. The client still decides what resources to request, but those it wants to fetch are available locally at request time. ("just" as a qualifier for nefariousness, not usefulness)
- deleted 9y ago
  [deleted]
spiderfarmer 9y ago
How is browser support for server push nowadays? Back in March Jake Archibald noticed a lot of oddities in mainly Safari and Edge: https://jakearchibald.com/2017/h2-push-tougher-than-i-thought/ https://jakearchibald.com/2017/h2-push-tougher-than-i-though...
poyu 9y ago
Here's a really nice write up on server push optimization from the Chrome team. Rules of Thumb for HTTP/2 Push https://docs.google.com/document/d/1K0NykTXBbbbTlv60t5MyJvXjqKGsCVNYHyLEXIxYMv0/edit https://docs.google.com/document/d/1K0NykTXBbbbTlv60t5MyJvXj...
TheAceOfHearts 9y ago
Please correct me if I'm wrong in anything I say here. I haven't had any real-world deployment experiences with HTTP 2.0. Every time I've tried looking into it, I've found it underwhelming. Infrastructure support and tooling is still heavily lacking as far as I can tell. To really take advantage of server push it seems like you'd need to have really good build tools available. Don't you risk sending useless data with server push? How do you handle cached resources? Just because a view depends on some resources, it doesn't mean you always need to send em down to the client. Having server push doesn't always mean you should avoid bundling and minifying resources. Won't a gzipped bundle typically produce a smaller payload? Maybe I'm totally wrong or I've misunderstood something, but the general impression I've gotten is that the benefits of server push are a bit overstated. Does anyone have links to resources which discusses these issues in depth?
- bfred_it 9y ago
  I think, but could be completely wrong, that browsers can reject a pushed resource at the start. Since the "connection" cost for each resource is minimal, this wouldn't be too much of a problem. Someone confirm or deny this.
  - querulous 9y ago
    with http2 server push the server first sends a frame advertising it's going to push some resource (denoted by it's uri). the client can reject this resource before it's sent. this means the server has to delay sending to give the client the opportunity, however
    - SahAssar 9y ago
      The server does not delay sending until the advertising frame is acknowledged. So, for a large push the client might cancel the push, but for small pushes the client will already have received the data before the cancel can reach the server. In general, if you are only pushing something that is both small and required that isn't a problem, but when using push for things like MPEG-DASH this becomes a point to think about.
pgjones 9y ago
Server push in Python https://pgjones.gitlab.io/quart/serving_http2.html#server-push-or-push-promises https://pgjones.gitlab.io/quart/serving_http2.html#server-pu... (I am the Quart author, thought this would be interesting and relevant).
- drcongo 9y ago
  As someone who loves Flask and finds Django infuriating, I've been keeping an eye on Quart, it looks really interesting.
mozumder 9y ago
This doesn't seem to have a level of "cache-aware server push" that h2o (awesome http/2 server) has. Is there any info on how Nginx deals with cached server push?
- vbtechguy 9y ago
  been testing Nginx 1.13.9 via master branch with my Centmin Mod Nginx stack and HTTP/2 push testing by setting up cache aware HTTP/2 push via conditional preload link resource hints headers which only show up when a cookie is absent https://community.centminmod.com/threads/hurray-http-2-server-push-for-nginx.11910/page-2#post-59423 https://community.centminmod.com/threads/hurray-http-2-serve... works so far but still waiting on bug fix https://trac.nginx.org/nginx/ticket/1478 https://trac.nginx.org/nginx/ticket/1478 as Nginx has pushed back 1.13.9 release until next week https://twitter.com/nginx/status/963442197436678144 https://twitter.com/nginx/status/963442197436678144
steeve 9y ago
Still no HTTP/2 backend support?
- x25519 9y ago
  No. Maxim's answer on this issue: https://mailman.nginx.org/pipermail/nginx/2015-December/049445.html https://mailman.nginx.org/pipermail/nginx/2015-December/0494...
linsomniac 9y ago
Just a heads up, we tried to enable H2 with haproxy 1.8.3 last week and had to roll it back because of a Firefox bug. I believe it's this one, which doesn't seem to be getting much attention: https://bugzilla.mozilla.org/show_bug.cgi?id=1427256 https://bugzilla.mozilla.org/show_bug.cgi?id=1427256
- ghusbands 9y ago
  On that bug, it looks like the reporter has yet to give an update detailing what the bug actually is (the connection header is a mislead). Their update on Dec 30th says "I'm still working closely together with Willy from Haproxy to determine the actual root cause of http2 failures in Haproxy which only seems to affect Firefox". Without information on the actual fault, it seems like there's little the Firefox developers can do. It could easily be a Haproxy bug.
- kolme 9y ago
  That's funny, we couldn't deploy H2 because there were problems with HAProxy/Apache and Safari. And it looks like a very similar issue: http://www.wiktorzychla.com/2017/06/http2-keep-alive-and-safari-browsers.html http://www.wiktorzychla.com/2017/06/http2-keep-alive-and-saf...
  - ghusbands 9y ago
    That bug is in HAProxy. The RFC clearly states that the presence of the Connection header makes the response malformed. "An endpoint MUST NOT generate an HTTP/2 message containing connection-specific header fields; any message containing connection-specific header fields MUST be treated as malformed (Section 8.1.2.6)." and "Clients MUST NOT accept a malformed response. Note that these requirements are intended to protect against several types of common attacks against HTTP [...]" (though Safari's response of repeatedly retrying as fast as possible is certainly problematic)
- x25519 9y ago
  That bug has been fixed in 1.8.3 (https://www.mail-archive.com/haproxy@formilux.org/msg28501.html https://www.mail-archive.com/haproxy@formilux.org/msg28501.h...) Source: https://bugzilla.mozilla.org/show_bug.cgi?id=1427256#c7 https://bugzilla.mozilla.org/show_bug.cgi?id=1427256#c7
niftich 9y ago
As more software is adding support for HTTP/2 server push, I hope they'll start supporting a higher-level, implementation-agnostic, declarative way of specifying resources to push, which operates at a layer higher than server config directives. Google has a dead-simple JSON format [1] for this from 2015. [1] https://github.com/GoogleChromeLabs/http2-push-manifest https://github.com/GoogleChromeLabs/http2-push-manifest
- SahAssar 9y ago
  Most servers just read the preload headers from the backend and use that as a push. That won't work with "HTTP 103 Early Hints" (Since it needs to know what to push before the backend responds), but for now a preload header is a good compromise between ease-of-use and good-enough.

189 points by x25519 9y ago

I've recently spent more time using H2O over nginx, mainly because of its more complete support of HTTP 2 (push, cache-aware push, ..) but also out of the box support for brotli compression and mruby (think lua landscape for nginx). Even though nginx made it easier to build and ship third party modules separately, I feel like the module community (as well as distro maintainers/packagers) haven't followed suit. There's obviously pre-baked packages like openresty which has lua world, but then there's no brotli.

youngtaff 9y ago
With you on that one - h2o is a lovely server
sureaboutthis 9y ago
My web dev company now has a few small clients on h2o for the same reasons. It gives us a chance to try h2o out without any downfall. Still very early but loving it.
SahAssar 9y ago
The nginx brotli module is very easy to build, I usually build my openresty with brotli and nchan as add in modules and have never encountered any issues.
vbtechguy 9y ago
been using ngx_brotli with my Centmin Mod Nginx stack for what seems like years now https://community.centminmod.com/threads/how-to-use-brotli-compression-for-centmin-mod-nginx-web-servers.10688/ https://community.centminmod.com/threads/how-to-use-brotli-c... :)
- jbergstroem 9y ago
  The upstream repo from google hasn't been updated in over a year; issues are being opened questioning maintainership. It additionally breaks against more recent version combos of nginx/brotli. There's an active fork here (which I also use on my remaining nginx instances) https://github.com/eustas/ngx_brotli https://github.com/eustas/ngx_brotli
  - vbtechguy 9y ago
    yup i am using eustas fork for ngx_brotli works well :)

x25519 9y ago

They did a static analysis and fixed a null pointer dereference here: https://hg.nginx.org/nginx/rev/8b0553239592 https://hg.nginx.org/nginx/rev/8b0553239592

jchb 9y ago
They might want to consider using clang nullability annotations (_Nullable etc) when compiling on clang. Can use a macro so it becomes a noop when the compiler does not support it. The static analyser would then get a lot of more information to work with, and it also serves as a kind of documentation.

alwillis 9y ago

Glad push support is finally about to ship.

seanwilson 9y ago

Are there any good general guidelines on when you should use HTTP2 push? Edit: Oops, I missed out "push" at the end.

ryantownsend 9y ago
You might want to read https://jakearchibald.com/2017/h2-push-tougher-than-i-thought/ https://jakearchibald.com/2017/h2-push-tougher-than-i-though... This is specific to H2 Push
- seanwilson 9y ago
  Yes, I read a few articles like this and it doesn't seem clear when you should use HTTP2 push.
crishoj 9y ago
I would suggest using HTTP/2 whenever possible. Features like connection multiplexing and pipelining alone are huge benefits.
- smartbit 9y ago
  Research by Homaan Behesti of Fastly (above at https://news.ycombinator.com/item?id=16365413#16365605 https://news.ycombinator.com/item?id=16365413#16365605) suggest that you test h2 with your site and see how h2 compares to h1.
eicnix 9y ago
According to [0] you can gain performance improvements pretty much in every scenario. [0] https://docs.google.com/presentation/d/1r7QXGYOLCh4fcUq0jDdDwKJWNqWK1o4xMtYpKZCJYjM/present?slide=id.p19 https://docs.google.com/presentation/d/1r7QXGYOLCh4fcUq0jDdD...
- niklasrde 9y ago
  With some exceptions, we found: https://medium.com/bbc-design-engineering/http-2-is-easy-just-turn-it-on-34baad2d1fb1 https://medium.com/bbc-design-engineering/http-2-is-easy-jus...

nodesocket 9y ago

Awesome. Is this going to make it into stable 1.12.X?

x25519 9y ago
No, new features don't usually get backported to the stable branch. It will ship with 1.13.9 (mainline) in 6 hours (at the time of writing). For stable branch, you need to wait until the 1.13 milestone is completed, which according to their roadmap (https://trac.nginx.org/nginx/milestone/1.13 https://trac.nginx.org/nginx/milestone/1.13) will be completed in 8 weeks.
spectrox 9y ago
It should be shipped with 1.13.9 according to the roadmap: https://trac.nginx.org/nginx/roadmap https://trac.nginx.org/nginx/roadmap

carlosvega 9y ago

Interesting video about HTTP 2. https://www.youtube.com/watch?v=0yzJAKknE_k https://www.youtube.com/watch?v=0yzJAKknE_k

smartbit 9y ago
Excellent talk & speaker, slides https://www.slideshare.net/Fastly/http2-what-no-one-is-telling-you https://www.slideshare.net/Fastly/http2-what-no-one-is-telli... Follow up talk Revisiting HTTP/2 given Jan 31, 2018 https://www.youtube.com/watch?v=wR1gF5Lhcq0 https://www.youtube.com/watch?v=wR1gF5Lhcq0 & slides https://www.slideshare.net/Fastly/revisiting-http2-87148462 https://www.slideshare.net/Fastly/revisiting-http2-87148462

ubercow 9y ago

How are you going to signal nginx what to push? Are you going to be able to push stuff from your application if using Nginx as a proxy? For example, a dynamic view that includes a css file hosted by nginx.

rictic 9y ago
Quoting the OP: > Also, preload links from the Link response headers, as described in https://www.w3.org/TR/preload/#server-push-http-2 https://www.w3.org/TR/preload/#server-push-http-2, can be pushed, if enabled with the "http2_push_preload" directive. So you send down some headers in your response which tells the proxy server resources it should push. Pretty elegant, and fails gracefully. I believe this is the same mechanism as other http2 servers.

deleted 9y ago

[deleted]

Mojah 9y ago

For those interested, I wrote a lengthy blogpost about HTTP/2 a few years ago, detailing the architectural/infrastructure changes needed to support it for your endusers: https://ma.ttias.be/architecting-websites-http2-era/ https://ma.ttias.be/architecting-websites-http2-era/

therealmarv 9y ago

Can somebody explain in simple words what HTTP/2 push means? Example?

detaro 9y ago
Browser: "Hey server, send me index.html please" Server: "Sure, here is index.html and you'll need style.css as well, so here is a second stream with that"
moviuro 9y ago
Client: may I get /index.html please? Server: sure, here's index.html, theme.css, and jquery.js. Client: hey wait! I didn't ask for... oh, nvm, good call. Now I can display all this without asking you for anything else. EDIT: See this: https://youtu.be/0yzJAKknE_k?t=30m52s https://youtu.be/0yzJAKknE_k?t=30m52s for more details
- abricot 9y ago
  And add-track.js, flash-banner.gif?
  - janfoeh 9y ago
    This is just fancy cache-prewarming. The client still decides what resources to request, but those it wants to fetch are available locally at request time. ("just" as a qualifier for nefariousness, not usefulness)
deleted 9y ago
[deleted]

spiderfarmer 9y ago

How is browser support for server push nowadays? Back in March Jake Archibald noticed a lot of oddities in mainly Safari and Edge: https://jakearchibald.com/2017/h2-push-tougher-than-i-thought/ https://jakearchibald.com/2017/h2-push-tougher-than-i-though...

poyu 9y ago

Here's a really nice write up on server push optimization from the Chrome team. Rules of Thumb for HTTP/2 Push https://docs.google.com/document/d/1K0NykTXBbbbTlv60t5MyJvXjqKGsCVNYHyLEXIxYMv0/edit https://docs.google.com/document/d/1K0NykTXBbbbTlv60t5MyJvXj...

TheAceOfHearts 9y ago

Please correct me if I'm wrong in anything I say here. I haven't had any real-world deployment experiences with HTTP 2.0. Every time I've tried looking into it, I've found it underwhelming. Infrastructure support and tooling is still heavily lacking as far as I can tell. To really take advantage of server push it seems like you'd need to have really good build tools available. Don't you risk sending useless data with server push? How do you handle cached resources? Just because a view depends on some resources, it doesn't mean you always need to send em down to the client. Having server push doesn't always mean you should avoid bundling and minifying resources. Won't a gzipped bundle typically produce a smaller payload? Maybe I'm totally wrong or I've misunderstood something, but the general impression I've gotten is that the benefits of server push are a bit overstated. Does anyone have links to resources which discusses these issues in depth?

bfred_it 9y ago
I think, but could be completely wrong, that browsers can reject a pushed resource at the start. Since the "connection" cost for each resource is minimal, this wouldn't be too much of a problem. Someone confirm or deny this.
- querulous 9y ago
  with http2 server push the server first sends a frame advertising it's going to push some resource (denoted by it's uri). the client can reject this resource before it's sent. this means the server has to delay sending to give the client the opportunity, however
  - SahAssar 9y ago
    The server does not delay sending until the advertising frame is acknowledged. So, for a large push the client might cancel the push, but for small pushes the client will already have received the data before the cancel can reach the server. In general, if you are only pushing something that is both small and required that isn't a problem, but when using push for things like MPEG-DASH this becomes a point to think about.

pgjones 9y ago

Server push in Python https://pgjones.gitlab.io/quart/serving_http2.html#server-push-or-push-promises https://pgjones.gitlab.io/quart/serving_http2.html#server-pu... (I am the Quart author, thought this would be interesting and relevant).

drcongo 9y ago
As someone who loves Flask and finds Django infuriating, I've been keeping an eye on Quart, it looks really interesting.

mozumder 9y ago

This doesn't seem to have a level of "cache-aware server push" that h2o (awesome http/2 server) has. Is there any info on how Nginx deals with cached server push?

vbtechguy 9y ago
been testing Nginx 1.13.9 via master branch with my Centmin Mod Nginx stack and HTTP/2 push testing by setting up cache aware HTTP/2 push via conditional preload link resource hints headers which only show up when a cookie is absent https://community.centminmod.com/threads/hurray-http-2-server-push-for-nginx.11910/page-2#post-59423 https://community.centminmod.com/threads/hurray-http-2-serve... works so far but still waiting on bug fix https://trac.nginx.org/nginx/ticket/1478 https://trac.nginx.org/nginx/ticket/1478 as Nginx has pushed back 1.13.9 release until next week https://twitter.com/nginx/status/963442197436678144 https://twitter.com/nginx/status/963442197436678144

steeve 9y ago

Still no HTTP/2 backend support?

x25519 9y ago
No. Maxim's answer on this issue: https://mailman.nginx.org/pipermail/nginx/2015-December/049445.html https://mailman.nginx.org/pipermail/nginx/2015-December/0494...

linsomniac 9y ago

Just a heads up, we tried to enable H2 with haproxy 1.8.3 last week and had to roll it back because of a Firefox bug. I believe it's this one, which doesn't seem to be getting much attention: https://bugzilla.mozilla.org/show_bug.cgi?id=1427256 https://bugzilla.mozilla.org/show_bug.cgi?id=1427256

ghusbands 9y ago
On that bug, it looks like the reporter has yet to give an update detailing what the bug actually is (the connection header is a mislead). Their update on Dec 30th says "I'm still working closely together with Willy from Haproxy to determine the actual root cause of http2 failures in Haproxy which only seems to affect Firefox". Without information on the actual fault, it seems like there's little the Firefox developers can do. It could easily be a Haproxy bug.
kolme 9y ago
That's funny, we couldn't deploy H2 because there were problems with HAProxy/Apache and Safari. And it looks like a very similar issue: http://www.wiktorzychla.com/2017/06/http2-keep-alive-and-safari-browsers.html http://www.wiktorzychla.com/2017/06/http2-keep-alive-and-saf...
- ghusbands 9y ago
  That bug is in HAProxy. The RFC clearly states that the presence of the Connection header makes the response malformed. "An endpoint MUST NOT generate an HTTP/2 message containing connection-specific header fields; any message containing connection-specific header fields MUST be treated as malformed (Section 8.1.2.6)." and "Clients MUST NOT accept a malformed response. Note that these requirements are intended to protect against several types of common attacks against HTTP [...]" (though Safari's response of repeatedly retrying as fast as possible is certainly problematic)
x25519 9y ago
That bug has been fixed in 1.8.3 (https://www.mail-archive.com/haproxy@formilux.org/msg28501.html https://www.mail-archive.com/haproxy@formilux.org/msg28501.h...) Source: https://bugzilla.mozilla.org/show_bug.cgi?id=1427256#c7 https://bugzilla.mozilla.org/show_bug.cgi?id=1427256#c7

niftich 9y ago

As more software is adding support for HTTP/2 server push, I hope they'll start supporting a higher-level, implementation-agnostic, declarative way of specifying resources to push, which operates at a layer higher than server config directives. Google has a dead-simple JSON format [1] for this from 2015. [1] https://github.com/GoogleChromeLabs/http2-push-manifest https://github.com/GoogleChromeLabs/http2-push-manifest

SahAssar 9y ago
Most servers just read the preload headers from the backend and use that as a push. That won't work with "HTTP 103 Early Hints" (Since it needs to know what to push before the backend responds), but for now a preload header is a good compromise between ease-of-use and good-enough.