So if you’ve ever had to increase table_open_cache in Ubuntu 20, you’ll probably find that it doesn’t work the traditional way. Which is mind blowing! But I have a guess as to why. It’s to stop you from blowing up your server from too many open files!
I had updated /etc/mysql/mysql.conf.d/mysqld.cnf with the following
However, MySQL was only showing the value set at 4945
After some Google searching, I found this thread https://askubuntu.com/questions/1241013/cannot-increase-mysql-table-open-cache-in-ubuntu-20-04
Which pointed me to /lib/systemd/system/mysql.service and the line LimitNOFILE
Based on the information in the post, the LimitNOFILE is causing an automatic change to the “table_open_cache” variable. Modifying it to say 20000 will allow you to go with an 8000 table_open_cache. Copy and pasting into WordPress wouldn’t have done this post justice. So I screenshotted it.
After making the changes and restarting MySQL I got table_open_cache set to 8000