Support » Plugin: Google XML Sitemaps » [Plugin: Google XML Sitemaps] XML Site-map generator using a boatload of memory

  • I’m doing the technical stuff for a small wordpress website. (As a favor). I’m fairly technical, but I only started to dig into web and wordpress stuff a few weeks ago.

    We use this sitemap generator plugin.
    It works.
    But I noticed a weird thing.
    When generating the sitemap, the plugin reports that it uses between 40 and 46.5MB of memory.
    I think that is an aweful lot !
    What does this number mean exactly ?
    Is it all memory in use by the apache/wordpress process that manages the website ? Including all plugins and other software used ?
    Or is it just the memory used by only the XML-sitemap generator plugin.
    The text suggest the last.
    But I can’t believe such a simple plugin needs 45MB of ram !

    The whole SQL database of the website is only a few MBs large. Something like 4 or 8 MB total. How can any plugin use 5 times more memory than the dataset it uses ?

    This is causing a real problem.
    Our ISP has limited the process on the webserver to 48MB of ram.
    Our sitemap includes posts, the frontpage, and categories.
    There are about 300 entries total in the sitemap.
    But when we include tags, the memory usage will jump over 48MB.
    There are quite a few tags, but only 2400. No big number when you talk about computers. Even if the plugin uses 1k memory for each entry, while building the sitemap, (2400 + 300) * 1k = still only 2.7MB.

    Because the plugin reports sometimes that it needs 46.5MB of ram during the build, I am afraid that even without including tags, we will soon go over 48MB. And then we can’t build a full sitemap anymore. So I rather resolve the problem now.

    So is this big memory usage a bug ? Or unoptimized programming ? Or is there no way around it ? Do other people have the same problem ? Or is my ISPs limit of 48MB unusually small ?

    Website is here:
    Sitemap is here:
    We are using WP 3.0.2, but the problem was there with 3.0.1 too.
    Plugin version: 3.2.4

    Thanks in advance,

Viewing 4 replies - 1 through 4 (of 4 total)
  • I have a little more data.
    I installed the TPC Memory Usage plugin.
    It seems the website is using 40-45MB constantly. So the number reported by this XML sitemap plugin is not memory usage of the plugin only, but usage of the whole process.

    Still, adding 2500 tags to the sitemap adds 3-5MB to memory usage. (Or more) And that pushes memory usage over the 48MB limit. Not good.

    Now I am wondering: is a base memory usage of 45 MB is normal or not ? Too bad the TPC Memory Usage plugin does not specify how much memory each plugin uses. I guess I’m gonna disable plugins one-by-one to see what impact on memory usage they have. But I can only do that during the “quiet hours”.

    No way to edit these posts ?

    Anyway, I copied the whole website to my own PC. I’m using Xampp for windows. I copied the SQL database and the whole wordpress folder from the original website. (And made a few small changes to the wp-config.php file for the new url: localhost). This allowed me to mess around with all plugins.

    WordPress install with Akismet, and no other plugins: 16.8MB.
    I enabled all plugins one by one, and got to a maximum of 23MB.

    I have no idea how and why we got to 45MB used on the webhost, and only 23MB on my local setup. Very weird.

    Maybe a memory leak ? Unfortunately I can find no way how to restart our process on the webhost. 🙁



    I’m having the same problem, only I didn’t install anything on my computer, I just opened the site’s log and there it was:

    PHP Warning: XSLTProcessor::transformToDoc() [xsltprocessor.transformtodoc]: Memory allocation failed : creating buffer in /home/domain/public_html/wp-content/plugins/google-sitemap-generator/sitemap-core.php on line 1552

    You didn’t say which version of the Google XML Sitemaps you are using. I’m using the beta one.

    We are using the latest non-beta version (as usual). 3.2.4.

    It seems XML sitemap generator uses a spike of a few MB while creating the sitemap. That’s fine, I guess. XML sitemap generator was the plugin that showed me there is a problem with memory on my server. But that doesn’t mean it is the cause.

    Once I realized that, I could remove my post here. Or keep it, and hope that someone would read it, and make a useful comment. I’ve spoken with a friend (who is not very technical, but does have a lot of experience with building websites). He told me that my webspace-provider might have installed a lot of stuff in apache or php, which can be statically linked to the executables. And thus cause a growth of my webserver process. Without me having any influence on it. I think it’s weird. Because that means they sell webprocess with 48M ram, but already use 25-30mb just because of apache/php.

    At the moment the website runs fine. I disabled 1-2 specific plugins, and the normal memory usage is 42/48M. I am now waiting to see if the server ever restarts/reboots. Then I can maybe see if we have a memory leak, or whether the high usage is normal.

Viewing 4 replies - 1 through 4 (of 4 total)
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