Enable compression for HTTP2 server-pushes on an apache server

Question

If I enable H2 for my apache server and specify a preloaded link header on a HTML Dokument, the server performs a H2 server-push because it parses the Link header -- so far so good.

The problem is that this pushed resource is delivered without compression.
I guess that's because a server-push doesn't create a HTTP request and therefore the accept-encoding request header is not provided. The thing is, I don't get any performance improvements if the client has to download the uncompressed content. Is it still possible to serve the content compressed? Maybe based on the accept-encoding request header from the HTML document?

My apache config:

<VirtualHost *:443>
    Protocols h2 http/1.1
    [...]
    <Location /index.html>
        Header add Link "</css/all.min.css>;rel=preload;as=style"
    </Location>
    [...]
</VirtualHost>

The HTML Headers:

Request headers from the HTML document

accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
accept-encoding:gzip, deflate, sdch, br
accept-language:de,en-US;q=0.8,en;q=0.6
cache-control:no-cache

Response headers from the HTML document

accept-ranges:bytes
cache-control:no-transform,public,max-age=300,s-maxage=900
content-encoding:gzip
content-length:2183
content-type:text/html
etag:"2472-5385af4b7bbda-gzip"
last-modified:Sun, 24 Jul 2016 05:29:47 GMT
link:</css/all.min.css>;rel=preload;as=style
server:Apache/2.4.18 (Debian)
status:200
vary:Accept-Encoding

Response headers from /css/all.min.css

accept-ranges:bytes
cache-control:no-transform,public,max-age=300,s-maxage=900
content-length:14237
content-type:text/css
etag:"379d-5385af4b9139b"
last-modified:Sun, 24 Jul 2016 05:29:47 GMT
server:Apache/2.4.18 (Debian)
status:200
vary:Accept-Encoding

Moritz · Accepted Answer · 2017-03-07T12:43:16.503

3

It seems like this is simply a bug in mod_http2, but it was fixed with version 1.2.6: https://github.com/icing/mod_h2/issues/86

edited Mar 07 '17 at 12:43

answered Jul 30 '16 at 15:51

Moritz

238
1
8

score -1 · Answer 2 · answered Jul 24 '16 at 20:14

-1

I think you should use mod_deflate:

http://httpd.apache.org/docs/current/mod/mod_deflate.html#enable

answered Jul 24 '16 at 20:14

Thomas

177
3
13

This would be a much better answer if you explained *why* you think mod_deflate should be used. – EEAA Jul 24 '16 at 21:09
It is not like compression wouldn't work at all, it just doesn't works for resources delivered with a server-push. – Moritz Jul 24 '16 at 21:38

Enable compression for HTTP2 server-pushes on an apache server

2 Answers2