Support » Plugins » [Plugin: W3 Total Cache] Page caching works on one machine, not on another

  • First, thanks so much for all your work on this plugin — it’s fantastic, and a pleasure to use.

    I have two instances of the same code base on two different servers (dev and QA instances). The same file permissions are in place for both. Both have the same plugins installed and enabled, and as far as I can tell, the W3TC config is the same for each. I have debugging turned on for both.

    The issue: Although I have page caching, DB caching, and minify turned on for both, only one is doing the page caching.

    The debug info for one instance includes the three sets of comments (minify, DB cache, page cache), and populates the pgcache directory with what you’d expect. On the other instance, the comments only include minify and DB cache. No page cache comments, and no files in the pgcache directory.

    Both instances serve up identical content, and neither is registering anything in the error logs. Neither WP admin settings page shows any errors or warnings. Each site is running PHP 5.2.4.

    Can you think of anywhere else I would look to debug this problem? Anything that might be different between the two servers? Would the presence or absence of any PECL libraries, etc., silently defeat page caching?

    Thanks again for all the work and community support.

Viewing 7 replies - 1 through 7 (of 7 total)
  • If you have copied files to the other server without activation it’s possible to have unexpected results.

    If page cache debug comments doesn’t exist it means advanced-cache.php doesn’t exist in wp-content/ or WP_CACHE is undefined in wp-config.php (there should be notifications for these) or page cache is disabled.

    Thanks for the info. I did install from scratch on both instances, so I don’t think that’s it — I verified that the plugin created its storage and config files on activation.

    I’ll do some closer debugging and update this post if anything interesting arises.

    Thanks again!

    Ok thanks.

    We identified the difference between the two installs: one had the WP_CACHE define() statement near the top of wp-config.php (worked), and the other had it at the bottom (didn’t work). Page cache started working when we moved the WP_CACHE statement to the top of wp-config.php.

    I haven’t explored why this would be the case. Have you heard of this before?

    No, was the one with the statement lower in wp-config.php below the “do not edit below this point” comment?

    I actually didn’t see it until it was fixed, but it must have been below the require_once(ABSPATH . 'wp-settings.php'); call — I think a sysadmin just added it as the very last line of wp-config.php.

    So I guess we can interpret this as meaning that you have to define this constant before wp-settings.php gets executed.

    Yes. Please mark this topic as resolved.

Viewing 7 replies - 1 through 7 (of 7 total)
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