[Plugin: W3 Total Cache] how do I know it's working

The easiest way is to view the source of a given page and check the HTML comment at the bottom of the page and refresh the page and see if the date / time have changed there each time you refresh.

Yup time is changing every time even though I have all caching turned on:

<!– Performance optimized by W3 Total Cache. Learn more: https://www.w3-edge.com/wordpress-plugins/

Minified using disk: basic
Page Caching using disk: enhanced (User is logged in)
Database Caching using disk: basic
Object Caching 1363/1368 objects using disk: basic

Served from: mydomain.com @ 2012-02-27 19:26:15 –>

Great so it’s not actually doing anything at all?

Any advice on finding out why and fixing it?

Many thanks!

Here’s my compatibility check result if anyone can shed any light on this for me. Many thanks!

———————————
Plugin Version: 0.9.2.4
PHP Version: 5.2.17 (PHP5 required for Minify, Rackspace CloudFiles, Microsoft Azure support)
Web Server: Apache
FTP functions: Installed (required for Self-hosted (FTP) CDN support)
Multibyte String support: Installed (required for Rackspace Cloud Files support)
cURL extension: Installed (required for Amazon S3, Amazon CloudFront, Rackspace CloudFiles support)
zlib extension: Installed (required for compression support)
Opcode cache: Not installed
Memcache extension: Not installed
HTML Tidy extension: Installed (required for HTML Tidy minifier suppport)
Mime type detection: Not installed (required for CDN support)
Hash function: Installed (hash) (required for NetDNA purge support)
Safe mode: Off
Open basedir: Off
zlib output compression: Off
set_time_limit: Available
mod_deflate: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_env: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_expires: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_headers: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_mime: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_rewrite: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_setenvif: Not detected (required for Page Cache (enhanced mode) and Browser Cache)

WordPress Resources

/.htaccess: OK
/wp-content: OK
/wp-content/uploads/2012/02: OK
Fancy permalinks: /%year%/%monthnum%/%postname%/
WP_CACHE define: Defined (true)
URL rewrite: Enabled
Network mode: No

MOne, the W3 cache is absolutely working. You can see it from the messages.

Your expectation is that once cached, the time stamp will become static for the duration of your cache, but W3 does not work that way. That’s how WPSuperCache etc do it, they convert all the stuff into just text/html. W3 is still serving via PHP, just that it’s not hitting the DB etc.

So you’ll see new timestamps as you do. But the cache *is* working.

This is how I benchmarked before and after. Deactivate the plugin – Run your front page through pingdom.com. Note the total time. Activate the plugin. Clear your browser cache. Open your site’s front page to cache it on server. Then run it through pingdom.com. Total time loaded should be drastically reduced.

@Nearly

You are at least partially incorrect. If using disk BASIC, the time stamp does in fact remain the same, time after time. I know this for fact as that is how I have W3TC setup on my server.

I am using disk basic because i noticed the time stamps were changing with disk enhanced. I am using the latest dev version 0.9.2.5b with mod_ruid2 activated with mod_php if it makes any difference.

@frederick
Could you please confirm if the time stamps using disk enhanced SHOULD change when the page refreshed if it is caching properly? As I too have been looking for an answer to that question since I would greatly prefer to use disk enhanced.

@ M One

If you’re on a server with CPanel installed, chances are W3TC will not be able to tell you whether or not the server you on has the modules required installed. I know this is the case with mod_deflate and mod_headers as it’s always shown Not Detected on every installation I’ve done, even though they are installed and working just fine. In such a case, you’d need to get in touch with your web hosting provider to find out for sure.

As for testing whether the plugin is working for you or not, Pingdom is a great way to test whether the difference is noticeable, but it’s not going to really test it to the extent that you’d probably like. I would suggest running a web page speed test on the website. You can run up to 10 page tests at a time, across quite a few countries, using variable speeds.

https://www.webpagetest.org/

I’d suggest testing it in a City/State that your data center does not reside in (i.e. if your hosts DC is in Dallas, TX then run the test in Chicago, IL or Dulles, VA). This way you get a more accurate speed test from other parts of the US, or World, instead of possibly inside the same DC as your using.

You may also want to see if your web hosting provider would install an Op-Code Caching tool, such as APC, as chances are, you’re going to notice more of a difference using APC than you do with Disk based caching. Once APC is enabled, you’d be able to choose that from the same drop-down as Disk & Disk Enhanced.

As for the time-stamp, using APC, until the cache is flushed, the time stamp for us doesn’t change. The same seems to apply for Disk Enhanced.

@ Nodeki

Thanks for the reply and confirmation on disk enhanced. I found in another thread on here recently that disk enhanced is in fact broken in the current release and DEV version. I hope Frederick has something cooking up for us soon, it’s been an awful long time since a release.

I do agree with Nodeki on the fact that most modules won’t show installed, I’ve seen that under php modules FCGI(cPanel), DSO(cPanel) and suphp(cPanel), only recently since I upgraded my WHM/ cPanel to 11.32 and enabled mod_ruid2 do all the modules actually show up as installed, even though there were before.

So I’ll stick with Disk basic for the moment until an update is released.

If you’re having this issue on your hosting provider, please submit a bug submission form to make sure I’ve addressed all these cases for the next release.