Support » Plugin: W3 Total Cache » [Plugin: W3 Total Cache] Cache Preload Fixes and Feature Enhancements

  • Hello everyone,

    Over the last month or so I have taken time to investigate what was happening with W3TC cache preload for version I have documented my work, but there is far too much to include here, so please look at for a full description of my results.

    I hope some of this will be helpful. W3TC is a useful plugin.

    In a nutshell, I discovered that W3TC Total Cache release version has four faults in the cache preload function that prevent successful operation of this feature. My post provides code corrections for these faults. I also show a fix for another fault with URL redirection for cache prime requests that can lead to a ‘too many redirects’ error.

    I have also proposed new features to ensure that pages are primed only when required; I have included an enhancement for visible monitoring and tracing cache preload activities; and I show how to enable different cache retention times depending on the page URL.

    The fixes that I propose apply to both basic mode and enhanced mode disk caching. I have tested basic mode disk caching, but I have only performed a cursory validation that the fixes will work for enhanced mode caching. As with any suggestions, I would hope that this work be reviewed by those who develop W3TC.

    Briefly, my document has 4 pages.

    Page 1. Describes the known faults or bugs in W3TC Total Cache version preload function. See

    Page 2. Describes a feature enhancement to enable setting of specific page cache expiry times. See

    Page 3. Describes a feature enhancement to allow administrator control and monitoring of prime activities. See

    Page 4. Describes a feature enhancement to prime only uncached and valid pages. This improves cache prime performance. See

    Again, I hope some of this will be helpful. And, I am pleased to contribute to this plugin. 🙂

Viewing 15 replies - 1 through 15 (of 37 total)
  • Great !

    Plugin Author Frederick Townes


    Thanks @wmiles, will check them out.

    any official take on this Frederick?

    Plugin Author Frederick Townes


    All of those faults are fixed in the next release except handling redirection (which was deliberately omitted). The feature enhancements were all in the roadmap already, but I appreciate the contributions, well done.

    When is the next release expected? It would be great to get a quick fix integrated to take care of the pre-loading bug.

    I’d rather get that fixed right away and wait for all the goodies a little further down the road.

    When can we expect the next release Frederick? I’m sure you have lots of new features and bug fixes in store for us!

    @frederick: any outlook on when version will be released /out of beta?

    In todays version the problem still persist. versione release is only simply security fix: all problems discovered on version is the same and unfixed … Nothing, for now, was fixed!

    Cache preloading is NOT fixed in I’ve got 100 websites that will need to be fixed manually when I upgrade to this version.

    Is there going to be another new release soon fixing this problem? I know it’s fixed in the development version, but when will it be corrected in the latest version?

    @kymvan versione release is only, and simply, the same of + security fix: all problems discovered on version is the same and unfixed on … Development version 2011-08-31 was substituted with … Nothing, for now, was fixed!

    You folks are actually using my cache fixes? Hmmm, how would anyone know?

    So, I took a moment to integrate my cache feature fixes into the release. The integration was easy, the code hasn’t changed, but there are other problems with Basic mode disk caching no longer works with

    Part of the security fix code has been put in the wrong place. For basic disk caching, the cached page is being prefixed with a nine byte ‘<?php /*’ text string. But this is inserted before the page expiry time and compressed page data is written. What this means is that the page expiry time is never picked up successfully when the cache page is referenced, so the page is always thought to be expired. Cached disk pages are never returned.

    I have posted an update on my blog. A version file is available that includes my cache prime enhancements and this code fix. Can someone let Frederick know about this? Leave a comment if you are so inclined.


    Your “cache prime enhancements” and re-build version, is based on ex official development version 2011-08-31 of W3 Total Cache?

    P.S. Please, indicate me the based version for your enanchements …

    @wmiles, yes we do use it for some time already 🙂

    Excellent work …

    I loadet wmiles version to my site ( )this morning.

    Till now it works very nice and it seems to be a bit faster.

    I vote for include the enhancements in the official version.

Viewing 15 replies - 1 through 15 (of 37 total)
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