Warning: The Similar URLs Plugin Will Slow Down Your Joomla Website

If you’re an avid reader of our blog, then you may already know that we’re not huge fans of sh404SEF. In fact, we have gained expertise in getting rid of it on large websites. So when something wrong happens to a website that has sh40SEF installed, we immediately suspect this notorious extension, and usually, we are not proven wrong!

Let us give you an example… Late last week a client came to us and told us that they were having some serious performance issues on their Joomla website. We knew that they were using sh404SEF and so we disabled the whole extension in order to confirm whether the problem was caused by sh404SEF or not. And, again, our suspicions were not wrong: the website worked at optimal speed once sh404SEF was disabled.

But, the client wanted sh404SEF and wasn’t ready to get rid of it (getting rid of sh404SEF on large websites is a painful project), and so he asked us to see what we can do about it. So, we checked the slow query log and we noticed that it was full of something like the following query:

select oldurl, newurl, id, dateadd from #__sh404sef_urls where newurl <> “” AND oldurl not like ‘%vmchk%’ AND newurl not like ‘%format=feed%’ AND newurl not like ‘%format=pdf%’ AND newurl not like ‘%print=1%’ AND oldurl not like ‘%__404__%’ AND ( soundex(oldurl) = soundex(‘rss/feed.html’) OR oldurl like ‘%rss%’ OR oldurl like ‘%feed%’) GROUP BY oldurl limit 500;

A quick search in the codebase revealed that these slow queries stemmed from the sh404SEF’s Similar URLs system plugin. So, in order to address the performance issue, all we needed to do was to disable that plugin.

But, doesn’t disabling the plugin have any negative repercussions on the website?

No – it doesn’t. In fact, what this plugin does is that it tries to redirect a URL with a small error (such as a typo) in it to the right URL. Now this is all fine and dandy and it sounds great on paper, but in practice, it is completely a different issue. First, it doesn’t work most of the times and second, when it does work, it can cause SEO issues (any respectable search engine out there doesn’t like to see dozens of links for the same article). So, disabling this plugin is in fact a duty for any Joomla administrator out there, since it hurts both performance and SEO.

If you have the Similar URLs plugin enabled on your Joomla website, and you are experiencing slowdowns, then try disabling it. That should help tremendously. If it doesn’t, or if you are a bit hesitant about disabling this plugin, then please contact us. We’ll give you the right advice, we’ll fix the problem for you, we won’t charge you much, and you will gain top-notch programmers (modesty here, modesty…) and true friends for life!

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