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Admin pages stop working after enabling object-cache (11 posts)

  1. aaronerk
    Posted 15 years ago #

    I have a clean installation of MU 2.7.1 which works great until I enable object-cache (eAccelerator or XCache).

    Once I do (by copying one of the object-cache.php files into wp-content), I can login to the administrative console once, but any refresh of the browser there after will result in a blank white screen. I can't get to any wp-admin pages until I clear the cache or remove object-cache.php.

    An interesting note is that the one single page load of my administrative dashboard, I do not have the site admin options, it's as if I'm a regular blog administrator rather than a site wide administrator.

    There are no php errors thrown what so ever. Just a blank white page.

    I'm running the wordpress on my local OSX dev box with MAMP 1.7:
    Apache 2.0.59
    MySQL 5.0.41
    PHP 5.2.3
    APC 3.0.14
    XCache 1.2.0
    Zend Optimizer 3.2.8

    But I've had issues on our production server which is a centos 5 box.

    Anyone seen anything similar or have a success story of caching and WPMU 2.7+ ?

  2. cafespain
    Posted 15 years ago #

    Blimey how many accelerators do you want? :)
    Try disabling one of the accelerators on your server and see if it works then.

  3. aaronerk
    Posted 15 years ago #


    Sorry if I confused you with my orig post. I'm only using one at a time, I just wanted to say that i got the same result with either eAccelerator or XCache.

  4. Ovidiu
    Posted 15 years ago #

    where did you get them from? I guess yo uare using the ones from ?

    if you'd be happy using the eaccelerator one, here is a way better and more up to date version: though it might involve recompiling your eaccelerator with these options"

    ./configure –with-eaccelerator-shared-memory –with-eaccelerator-sessions –with-eaccelerator-content-caching

  5. aaronerk
    Posted 15 years ago #


    That's exactly my problem. I'm apparently using very dated object-cache.php files! They are in the README.txt, so why wouldn't I figure they were still current? The version you suggest is appearing to work although I haven't given it a full run down. Thanks a ton! Anyone else know of newer object-cache implementations? Perhaps we can update the WPMU readme file.

  6. andrea_r
    Posted 15 years ago #

    Perhaps you can update the trac with a ticket so the readme can get updated. :)

  7. Ovidiu
    Posted 15 years ago #

    well, the one at murmatrons is the best I have found so far and works with eaccelerator which suits me ;-)

  8. aaronerk
    Posted 15 years ago #

    Ticket to resolve the README.txt has been submitted:

  9. fritzdsouza
    Posted 15 years ago #

    hi am not using any accelerators but am also getting blank white pages for my mu install based on 2.7
    there are no errors shown in error logs either
    searching and googling have found that few issues can the be there with some of the mu loops today the server just started serving blank white pages and the issue was solved after a restart
    and sometimes the server segfaults and needs to be restarted again
    am still trying to figure out what might cause the segfault and sudden blank pages

  10. pressdev
    Posted 14 years ago #

    I've got similiar symptoms to those above, but there seem to be no existing remedies for my particular problem.

    It's a WP MU install version 2.8.4. Trying to use the Memcache object cache plugin with batcache at the page level per the setup here.

    I've been sure to upgrade object-cache.php, and have tried all flavors of the PHP memcache module. The symptoms are hanging admin pages and segfaulting Apache processes. Page caching is doing fine, indicated by the batcache meta data in the <head> of my HTML files.

    For some reason, the problem does not affect all blogs. And it seems to only be for users with administrative privileges. Based on debugging so far it looks like the WP install doesn't recognize admin users as logged in, or maybe caches some bad stuff that make them seem like non-admins.

    I was hopeful that this was a fix -- it appears to fix this issue -- but sadly the fix doesn't resolve my segfaults or hanging admin pages.

    It seems like others may be having issues as well.

    I attempted to debug object-cache.php with error_log() statements. You can see the output chain here.

  11. pressdev
    Posted 14 years ago #

    I'm not sure if this has anything to do with my issues, but I did notice recently that the detaul expiration time for objects cached by object-cache.php is 0 -- that is, they never expire. This is a terrible idea and you'll want to change that promptly.

    At this point I have to question why we would use object-cache.php at all if we can preserve page-level caching via batcache. We can't really afford to have anything in wp-admin cached or, for example, when you hit the preview button it could try to send you to preview someone else's post.

    As for the problem that drove me to reopen this thread, I'm thinking it might have also cached bad auth permissions which might have caused the wp-admin pages to hang.

About this Topic

  • Started 15 years ago by aaronerk
  • Latest reply from pressdev