gzip is failing for js / css files

have you ran update.php yet?

Does the error go away if you remove the new .htaccess changes in sites/default/files/advagg_js? Keep only what's in the FilesMatch section.

What version of apache are you using?

Here's the latest patch for core .htaccess
https://www.drupal.org/node/2193333#comment-11460765

Keeping this open as I would like to code fix for this.

What's you exact server environment? I'm also using Apache 2.4. Being able to replicate this behavior would allow for me to get a proper fix in place.

https://httpd.apache.org/docs/2.4/mod/core.html#loglevel
If you're wondering what I'd do, I put this in the apache config
LogLevel trace6
And then issue a single request and see why gzip wasn't returned.

Example outputs from the php status page. This should help me if you can provide this info

Apache Version 	Apache/2.4.6 (CentOS) OpenSSL/1.0.1e-fips PHP/7.0.12 

Apache Version 	Apache/2.4.18 (Win32) OpenSSL/1.0.2e PHP/7.0.5 

_SERVER["SERVER_SOFTWARE"]	nginx/1.8.1
PHP Version 5.5.24

It seems that the rewriting breaks the location of the file and prepends the apache document root to the physical path:

[Wed Nov 09 10:18:04.778559 2016] [core:trace3] [pid 21224] request.c(293): [client 10.100.2.1:44199] request authorized without authentication by access_checker_ex hook: /usr/share/drupal7/sites/default/files/advagg_css/css__FnTpFpH-6tcTOmqJuy5zo3HGSIcbCl6s-XvhyFVxz0Y__iXz2uJeWzlAwQFh7z-P7AWWiccKpz7R1CO7p_W_hCuI__CSmmOfvrcJ37eC8dYBc1UyTLvkzKP-qmPJK65zdsgSs.css.gz, referer: http://test.xxx/drupal7/                   
[Wed Nov 09 10:18:04.778593 2016] [core:info] [pid 21224] [client 10.100.2.1:44199] AH00128: File does not exist: /opt/mmh/www/napps/usr/share/drupal7/sites/default/files/advagg_css/css__FnTpFpH-6tcTOmqJuy5zo3HGSIcbCl6s-XvhyFVxz0Y__iXz2uJeWzlAwQFh7z-P7AWWiccKpz7R1CO7p_W_hCuI__CSmmOfvrcJ37eC8dYBc1UyTLvkzKP-qmPJK65zdsgSs.css.gz, referer: http://test.xxx/drupal7/                                                          

These are the final two lines from a trace6 output. My document root is /opt/mmh/www/napps while drupal runs from /usr/share/drupal7

I am running Ubuntu 14.04 LTS

Removing the new IfModule mod_headers.c block from the .htaccess files in advagg_js and advagg_css fixes it for me in the sense that my JS and CSS files are served again, compressed with gzip.

I Coping core; going to try something else
http://cgit.drupalcode.org/drupal/tree/.htaccess#n156

Can you try this?

<IfModule mod_rewrite.c>
  RewriteEngine on
  Options +FollowSymLinks

  # Serve brotli compressed JS files if they exist and the client accepts br.
  RewriteCond %{HTTP:Accept-encoding} br
  RewriteCond %{REQUEST_FILENAME}\.br -s
  RewriteRule ^(.*)\.js $1\.js\.br [QSA]
  RewriteRule \.js\.br$ - [T=application/javascript,E=no-gzip:1]

  <IfModule mod_headers.c>
    <FilesMatch "\.js\.br$">
      # Serve correct encoding type.
      Header set Content-Encoding br
      # Force proxies to cache gzipped & non-gzipped css/js files separately.
      Header append Vary Accept-Encoding
    </FilesMatch>
  </IfModule>

  # Serve gzip compressed JS files if they exist and the client accepts gzip.
  RewriteCond %{HTTP:Accept-encoding} gzip
  RewriteCond %{REQUEST_FILENAME}\.gz -s
  RewriteRule ^(.*)\.js $1\.js\.gz [QSA]
  RewriteRule \.js\.gz$ - [T=application/javascript,E=no-gzip:1]

  <IfModule mod_headers.c>
    <FilesMatch "\.js\.gz$">
      # Serve correct encoding type.
      Header set Content-Encoding gzip
      # Force proxies to cache gzipped & non-gzipped css/js files separately.
      Header append Vary Accept-Encoding
    </FilesMatch>
  </IfModule>
</IfModule>

<FilesMatch "^js__[A-Za-z0-9-_]{43}__[A-Za-z0-9-_]{43}__[A-Za-z0-9-_]{43}.js(\.gz|\.br)?">
  # No mod_headers. Apache module headers is not enabled.
  <IfModule !mod_headers.c>
    # No mod_expires. Apache module expires is not enabled.
    <IfModule !mod_expires.c>
      # Use ETags.
      FileETag MTime Size
    </IfModule>
  </IfModule>

  # Use Expires Directive if apache module expires is enabled.
  <IfModule mod_expires.c>
    # Do not use ETags.
    FileETag None
    # Enable expirations.
    ExpiresActive On
    # Cache all aggregated js files for 52 weeks after access (A).
    ExpiresDefault A31449600
  </IfModule>

  # Use Headers Directive if apache module headers is enabled.
  <IfModule mod_headers.c>
    # Do not use etags for cache validation.
    Header unset ETag
    # Serve correct content type.
    Header set Content-Type application/javascript
    <IfModule !mod_expires.c>
      # Set a far future Cache-Control header to 52 weeks.
      Header set Cache-Control "max-age=31449600, no-transform, public"
    </IfModule>
    <IfModule mod_expires.c>
      Header append Cache-Control "no-transform, public"
    </IfModule>
  </IfModule>
  ForceType application/javascript
</FilesMatch>

Thinking I might need to add
Options +FollowSymLinks
To the file. Does that make it work?

I can't reproduce this bug locally; can anyone test and see if this fixes the issue for you?

#19 has been committed. Please change the status if this is still a problem.

Just wanted to add that we were having the same problem where CSS/JS files were not being compressed after upgrading to 7.x-2.19. We found that just adding "RewriteEngine On" to the .htaccess files in the advagg directories fixed the problem. Then, we found this issue(!). In our case, adding "FollowSymLinks" was not needed. This patch does fix the issue.

For reference, we're running Apache/2.2.15 (Unix) with PHP 7.0.14. The strange thing was that it worked fine running under MAMP (Apache/2.2.31 (Unix), PHP 7.0.12). Not sure what difference might be.

I tryed to aply this patch but has errors:

/sites/all/modules/advagg$ patch < advagg.patch
patching file advagg.install
Hunk #1 succeeded at 2599 with fuzz 1 (offset 1822 lines).
patching file advagg.missing.inc
Hunk #1 FAILED at 451.
1 out of 1 hunk FAILED -- saving rejects to file advagg.missing.inc.rej

After that my site returns Error 500