Background of the issue:
I have installed and activated WPML (version 4.7.6) on my live site, hidden link, which receives considerable traffic. The site is running on WordPress 6.7.2 & PHP 8.2.28. After activation, everything works fine initially.
Symptoms:
After roughly 4–5 hours of WPML being enabled, the site slows down dramatically until it becomes unreachable. Disabling WPML restores normal performance within seconds. This issue cannot be reproduced on the staging server, even under load.
Questions:
How can we trace and resolve the performance degradation caused by WPML?
Would enabling WPML performance debug logs help in diagnosing the issue?
Would performing a database cleanup or any specific configuration help in resolving the issue?
Thank you for contacting WPML support. While you wait for one of my colleagues to take this ticket and work on it, let me provide you with the first debugging steps or see if I can help with the issue quickly.
String Translation, our main add-on, is not active on your site.
Could you please install and activate it, and then check if it helps improve the performance of your site?
Thank you for your quick reply and for suggesting that I install and activate WPML String Translation. I did so right away, but unfortunately the issue persists: about 4-5 hours after WPML is enabled, the site’s performance degrades severely until it becomes unreachable. Disabling WPML still restores normal performance within seconds.
Could you recommend additional steps to diagnose and resolve the problem? If you need more details or temporary access to the staging/production environment, please let me know.
Thanks in advance for your assistance. I look forward to your next suggestions.
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Hi there!
Where do you see the performance drop? Is it cpu, memory or something else?
Did you try by any chance disabling toolset instead of WPML and see if something changes?
Or checking for slow queries?
Would you be able to setup a staging site and check if the problem happens there as well so we can rule out any possible issue linked to traffic and also work more securely?
Thanks for the guidance. I’ll need about 1–2 days to set up the necessary tests and monitor the server’s resource usage (CPU, memory, slow queries, etc.). Once I’ve completed the tests, I’ll send you the detailed data and logs so we can proceed with the diagnosis.
