如何在Debain上使用Concrete5对“编译指示：无缓存”进行故障排除？

Question

Setup

• Debian GNU/Linux 7.6 (wheezy) will full access to Apache and virtual host files.
• Concrete5 CMS: http://www.concrete5.org/

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Problem

Our website is sending Pragma: no-cache in headers which is stopping a number of optimisations from working - including the CloudFlare service: https://www.cloudflare.com/

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Solutions which didn't work

When researching, we either didn't understand the answers or they seemed to be for specific use cases (like Oracle or php frameworks we're not using) but we did try the following:

1. Force caching via the site's .htaccess :

<FilesMatch "\.(ico|jpeg|png|gif|js|css)$">
   Header unset Cache-Control
   Header unset Pragma
</FilesMatch>

2. Force caching via Concrete5's header.php file

    header("Cache-Control: max-age=2592000"); //30days (60sec * 60min * 24hours * 30days)

3. Search site's root for no-cache using grep

    $ grep -r "no-cache" * .
    backup/databasebackup.php:header('Cache-Control: no-cache, must-revalidate');
    concrete/core/controllers/single_pages/login.php: header("Cache-Control: no-store, no-cache, must-revalidate");
    concrete/core/controllers/single_pages/login.php: header("Pragma: no-cache");
    concrete/js/tiny_mce/plugins/spellchecker/rpc.php:header("Cache-Control: no-store, no-cache, must-revalidate");
    concrete/js/tiny_mce/plugins/spellchecker/rpc.php: header("Pragma: no-cache");
    concrete/libraries/3rdparty/securimage/securimage.php: header('Cache-Control: no-store, no-cache, must-revalidate');
    concrete/libraries/3rdparty/securimage/securimage.php: header("Cache-Control: no-store, no-cache, must-revalidate");
    concrete/libraries/3rdparty/securimage/securimage.php: header("Pragma: no-cache");

But after looking at the files/scripts Concrete5 is setting no-cache on (login, database backups, text editor configs etc), we kind of understand why - plus these seem to be for specific files, not the entire site right?

4. Make a blank php file, request it and check the header

The blank file was served with caching on so we suspect that php is the culprit - but have no idea how to isolate the cause sorry.

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Question

How do we troubleshoot and fix this issue?

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Skill level

We do front-end design and understand the basics on how to setup and serve a CMS but don't have much experience with server configuration or troubleshooting cache issues.

We have command line access to the server and pretty much have full access to Debian, Apache, and the site's install.

Any help would be much appreciated.

Cheers

Ben

Answer 1

Update

To add max-age in a PHP script:

header("Cache-Control: max-age=xxxx");

Where xxxx is the number of seconds to cache, zero for no cache.

OR

If you configure by Content-Type (MIME Type)

header('Content-Type: text/html; charset=utf-8');

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Header Set Cache-Control "max-age=0, no-store"

to configure cache by Content-Type (MIME Type):
In .htaccess ot httpd.conf

ExpiresByType text/html "access plus 30 day"
ExpiresByType text/css "access plus 30 day"
ExpiresByType text/javascript "access plus 30 day"
ExpiresByType image/gif "access plus 1 year"
ExpiresByType image/jpg "access plus 1 year"
ExpiresByType image/png "access plus 1 year"

If these methods are not working you need to majke sure the modules are loaded.

You need access to httpd.conf

LoadModule expires_module     libexec/mod_expires.so
LoadModule headers_module     libexec/mod_headers.so

AddModule mod_expires.c
AddModule mod_headers.c
...
AddModule mod_gzip.c

Note that the load order is important in Apache/1.3x, mod_gzip must load last, after all other modules.

For Apache/2.0:

LoadModule expires_module modules/mod_expires.so
LoadModule headers_module modules/mod_headers.so
LoadModule deflate_module modules/mod_deflate.so

end of Update

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You should add the same cache based on MIME Type as well as (or rather than) file extension.

The cache should be max-age.

The W3C says max-age takes precedence over all other cache headers.

To troubleshoot you are doing well already if you are not getting "Internal Server Error 500"

In FireFox or Chrome

• Right Click page
• Select Inspect Element
• Go to the "Network Tab"
• Change Type from "All" to "HTML"
• Click on the HTML page in the list

You should be able to see exactly what is in the HTTP Response Header.

FireFox

Chrome

Answer 2

Finally got to the bottom of this, some of the Concrete5 Blocks on pages are stopping the pages from being cached.

If we turn on "Force full page caching" then we see some weird behaviour because the functionality is frozen by the cache, so we've had to turn it off.

Essentially, we can't cache the site fully because of the functionality in blocks on the page. We can only use APC caching.