Setup
Debian GNU/Linux 7.6 (wheezy) will full access to Apache and virtual
host files.
Concrete5 CMS: http://www.concrete5.org/
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/
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.
Question
How do we troubleshoot and fix this issue?
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
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');
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
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
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.
Related
Now this bug has lasted long enought. I have tried everything to stop the caching. Everything on the following stackoverflow links:
Chrome - Disable cache for localhost only?
Disabling Chrome cache for website development
Using <meta> tags to turn off caching in all browsers?
How to prevent Browser cache for php site
How to control web page caching, across all browsers?
How to prevent http file caching in Apache httpd (MAMP)
And also i tried to rightclick on the reload button on chrome and choose reload page complete and empty cache and reload page completely. I use PHPStorm as IDE but i also tried switching to notepad++ in case PHPStorm wasn't saving the file properly. Tried setting timestamps in the header so my requests to the page isn't identical. I am running on localhost XAMPP. Any solutions/ideas/guesses are more than welcome.
Note
Restarting XAMPP actually clears the cache (or at least forces the browser to reload the content). I have no idea why. Thanks in advance
Note
My PHP codes are being cached as well. When i edit my PHP codes and i refresh the page, it runs the old codes again. It's probably because the browser still shows the cached version of the page but thought it was worth mentioning.
There isn't much info here; but you might want to have a look at your php.ini and especially your revalidate_freq. It should preferably be 0 for development; but definitely not bigger than then default of 2 seconds.
Create a .htaccess file under root directory and put the below code inside .htaccess file.
check if you have mod_rewrite enable in the server (optional).
Add it stops caching the pages
#Initialize mod_rewrite
RewriteEngine On
<FilesMatch "\.(html|htm|js|css)$">
FileETag None
<IfModule mod_headers.c>
Header unset ETag
Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate"
Header set Pragma "no-cache"
Header set Expires "Wed, 12 Jan 1980 05:00:00 GMT"
</IfModule>
</FilesMatch>
Please check below mentioned solution, It will help you.
Step 1:
In HTML head tag you should add below mentioned lines.
<meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate"/>
<meta http-equiv="Pragma" content="no-cache"/>
<meta http-equiv="Expires" content="0"/>
So with this when user visits your page, every time new content will fetch from server.
Step 2:
By using .htaccess you can prevent page 100% being cached by browser.
<filesMatch "\.(html|htm|js|css)$">
FileETag None
<ifModule mod_headers.c>
Header unset ETag
Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate"
Header set Pragma "no-cache"
Header set Expires "Wed, 11 Jan 1984 05:00:00 GMT"
</ifModule>
</filesMatch>
Step 3:
If your page is in PHP than add this line on the top of the page.
header("Cache-Control: no-store, no-cache, must-revalidate, max-age=0");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
header("Expires: 0");
Let me know if it not works.
i install a chrome Extension that clear cache. i config it to clear cache with CTAL+Q - so insead of refresh page with F5 or CTRL+R i use this Extension - it solve my developin cache problems ( i use polymer framework - and i have same problems as you )
i use this extension
I have a problem that one of my users, make an insert into my mysql database, but when he goes to another page to list these inserts, it only return old data that was previous there. He can only see the changes after several minutes or even hours.
I read that If I add a random number in my url, I can avoid cache, but still not working.
I tried to put these headers on php.
header("Cache-Control: private, no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
And I tried this one too:
SELECT SQL_NO_CACHE...
None work. Still don't get any visible changes.
Try using the Expires headers in your htaccess file. You will need to ask your user to Ctrl+F5 (Force refresh) for it to correctly take effect;
<IfModule mod_expires.c>
ExpiresActive on
ExpiresByType text/html "access plus 0 seconds"
</IfModule>
This will tell the browser not to cache the text and html within that directory and any subdirectories (unless otherwise specified). I had a similiar issue and resolved it with this when I realised my caching was affecting the update of live data.
When I specify:
header('Cache-Control: max-age=31557600');
the result header is
Cache-Control: max-age=31557600, max-age=0
It seems to still work, but it seems what php is doing is combining my Cache-Control header with what it sends if I don't specify the header.
Is there a way to nuke the second max-age=0 in php?
The culprit was mod_expires
When mod_expires is active, and the line
ExpiresDefault A0
is present, it will put max-age=0 on anything that doesn't match one of its ExpiresByType directives.
So if using a php wrapper for something you want browsers to cache, don't set ExpiresDefault to anything and make sure there is not an ExpiresByType set for the same mime type.
I have flv files on my server which have changing content but not necessarily changing names.
I am having an issue whereby the flv files send headers which set the file to cache. As sometimes the same user may require the same file with different content later the files need to tell the browser not to cache them.
I have tried using something similar to PHP's header() command but when I run:
Curl -I myfile.com/file1.flv
The headers are still there.
Any help please?
I am not sure how you tried using PHP for this, it is apache which is processing and dispatching the file so best to start there.
Try the below:
1) Enable headers.load (headers module) on apache. Else wont work.
2) add below to .htaccess. This will capture file types of all the below formats and set them not to cache.
<FilesMatch "\.(jpg|gif|js|css|ico|swf|zip|pdf|doc|htc|xls|rtf|odt|wav|mp3|avi|wmv|mov|txt|flv)$"> FileETag None
<IfModule mod_headers.c>
Header unset ETag
Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate" Header set Pragma "no-cache"
Header set Expires "Wed, 11 Jan 1984 05:00:00 GMT"
</IfModule>
</FilesMatch>
3) restart apache.
4) Try 'curl -i www.url.com/file.flv' command again.
You should see the headers tell the file to not cache.
I'm trying to control the caching of files within a certain directory. I want the default cache time to be 15 minutes, but I want to let the application change it if necessary. For example, I may have a PHP script that I want to refresh every 1 minute, so I'll set the cache-control headers within PHP for that script. But for all of the other files I just want the cache time to be 15 minutes, and some of those are static files, so I can't just set a default cache-time in PHP.
I currently have this in my Apache config:
<Directory />
Options FollowSymLinks
AllowOverride None
Header set Cache-Control "max-age=900"
</Directory>
This works great for 99% of the cases, where I just want a 15 minute cache. However, if my PHP script sets a cache-control header, then this setting will overwrite it.
I've looked at the documentation for mod_header and none of the settings (unset, add, append, etc.) seem to give me what I need.
Thanks in advance.
Take a look at mod_expires instead http://httpd.apache.org/docs/2.2/mod/mod_expires.html. The docs say that it won't overwrite headers created by your PHP script:
"When the Expires header is already part of the response generated by
the server, for example when generated by a CGI script or proxied from
an origin server, this module does not change or add an Expires or
Cache-Control header."
Here is an example config for mod_expires:
<IfModule mod_expires.c>
ExpiresActive on
ExpiresDefault A600
ExpiresByType image/gif "access plus 1 day"
ExpiresByType image/jpeg "access plus 1 day"
ExpiresByType image/png "access plus 1 day"
ExpiresByType image/x-icon "access plus 1 day"
<FilesMatch "\.(php|php4)$">
ExpiresByType text/html "now"
</FilesMatch>
</IfModule>
Taken from http://howto.gumph.org/content/reduce-webserver-bandwidth/
Good luck!
According to php manual
<?php
header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past
?>
By sending the headers above, you should override any settings that may otherwise cause the output of your script to be cached.