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.
Related
I have a php script which copies an image to a folder every hour over writing the last image, the name of the image is always the same, image.jpg , im using ifttt to post the image to a website but the image posted is always the same image even though I have checked to see the image is different. so it must be posting the image from the cache? I added clearstatcache(); to the code but it doesn't work. is there any other way of clearing the cache so the actual image is posted? the image is hosted on a shared server. Thanks
$from = '/A1';
$files = scandir($from);
$to = '/A2';
if (!empty($files[2])) {
rename("{$from}/{$files[2]}", "{$to}/image.jpg");
}
clearstatcache();
solved with .htaccess file
<FilesMatch "\.(css|flv|gif|htm|html|ico|jpe|jpeg|jpg|js|mp3|mp4|png|pdf|swf|txt)$">
<IfModule mod_expires.c>
ExpiresActive Off
</IfModule>
<IfModule mod_headers.c>
FileETag None
Header unset ETag
Header unset Pragma
Header unset Cache-Control
Header unset Last-Modified
Header set Pragma "no-cache"
Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate"
Header set Expires "Thu, 1 Jan 1970 00:00:00 GMT"
</IfModule>
</FilesMatch>
Thanks for all your help!
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.
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 want to cache all of my files but I can't figure out how to get it to work so that the tests approve. I have currently
<meta http-equiv="Cache-Control" content="private" />
<meta http-equiv="Expires" content="86400000" />
<meta http-equiv="Cache-Control" content="max-age=86400000" />
The last line I added just to test if having expires and max-age will help (it doesn't)
I was using http://www.webpagetest.org/, https://developers.google.com/pagespeed/#, and http://gtmetrix.com/
can anyone tell me simply how to make sure everything is cached privately? I have checked a bunch of other pages but no one gives legit HTML code. Please list actual code don't just tell me to use Cache-Control and expires and that like every other website I have seen uses. I really need example code in order to understand. Thank you for any help in advance. I am also using PHP so if doing it in a header() then that would work too.
Thank you very much
edit: I also tried using .htaccess in order to do it but that didn't work. I don't know if it was a setting with my server or what but it didn't change anything with the test.
When you specify an expiration time in an HTML document, it only applies to the actual document.
Assuming you have an Apache webserver with mod_expires enabled, you can create a file named .htaccess and include the following
ExpiresActive On
ExpiresByType image/gif 86400000
ExpiresByType image/png 86400000
ExpiresByType image/jpg 86400000
ExpiresByType image/jpeg 86400000
ExpiresByType text/html 86400000
ExpiresByType text/javascript 86400000
ExpiresByType text/plain 86400000
you can use .htaccess to cache your files.
#cache html and htm files for one day
<FilesMatch ".(html|htm)$">
Header set Cache-Control "max-age=43200"
</FilesMatch>
#cache css, javascript and text files for one week
<FilesMatch ".(js|css|txt)$">
Header set Cache-Control "max-age=604800"
</FilesMatch>
#cache flash and images for one month
<FilesMatch ".(flv|swf|ico|gif|jpg|jpeg|png)$">
Header set Cache-Control "max-age=2592000"
</FilesMatch>
#disable cache for script files
<FilesMatch "\.(pl|php|cgi|spl|scgi|fcgi)$">
Header unset Cache-Control
</FilesMatch>
I'm trying to control the caching of files within a certain directory. I want the default cache time to be 15 minutes, but I want to let the application change it if necessary. For example, I may have a PHP script that I want to refresh every 1 minute, so I'll set the cache-control headers within PHP for that script. But for all of the other files I just want the cache time to be 15 minutes, and some of those are static files, so I can't just set a default cache-time in PHP.
I currently have this in my Apache config:
<Directory />
Options FollowSymLinks
AllowOverride None
Header set Cache-Control "max-age=900"
</Directory>
This works great for 99% of the cases, where I just want a 15 minute cache. However, if my PHP script sets a cache-control header, then this setting will overwrite it.
I've looked at the documentation for mod_header and none of the settings (unset, add, append, etc.) seem to give me what I need.
Thanks in advance.
Take a look at mod_expires instead http://httpd.apache.org/docs/2.2/mod/mod_expires.html. The docs say that it won't overwrite headers created by your PHP script:
"When the Expires header is already part of the response generated by
the server, for example when generated by a CGI script or proxied from
an origin server, this module does not change or add an Expires or
Cache-Control header."
Here is an example config for mod_expires:
<IfModule mod_expires.c>
ExpiresActive on
ExpiresDefault A600
ExpiresByType image/gif "access plus 1 day"
ExpiresByType image/jpeg "access plus 1 day"
ExpiresByType image/png "access plus 1 day"
ExpiresByType image/x-icon "access plus 1 day"
<FilesMatch "\.(php|php4)$">
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.