High CPU and Process Consumption

Hello, how are you?

We have version 11 installed and we are facing some unusual difficulties
with the theme on the website: https://www.jmais.com.br

Print: https://drive.google.com/file/d/1D0rUznJG1G8uUDZUjSeLO5e5ikiZXBiV/view?usp=sharing

Our 100% dedicated server is for jmais.com.br
300GB SSD
12 GB RAM
6 NUCLEOS CPU
+ PROTECTION AND CACHE CLOUD FLARE

After installing the theme, we observed a large increase in server resource consumption, even with the number of accesses considered simultaneous than 100 visitors online. A sudden surge in CPU and PROCESSES happens out of nowhere even with a constant number of hits.

We have experience with our server and it is capable of handling more than 1500 visitors online, and reaching 200 is already crashing.

Can you guide me in what might be happening?

Here are the errors that we identified, we do not know if it is related to this slowness.
1) Error that is reporting in the error log is:

[27-Jun-2021 18:45:51 UTC] WordPress database error Commands out of sync; you can’t run this command now for the SHOW FULL COLUMNS FROM wp_options query done by shutdown_action_hook, do_action(‘shutdown’), WP_Hook->do_action, WP_Hook->apply_filters, td_options::on_shutdown_save_options, update_option

2) Error, from http follows the print: https://drive.google.com/file/d/11KtmEo_Oa7ZirlizDEkk0zu7BPNrknd3/view?usp=sharing

As for the plugins, we are only using Adrotate and your originals.

We await a solution.

Sincerely, Rudmar from Brazil

2) Error, from http follows the impression: It has already been fixed!

It’s not that simple for us this news portal has high traffic, and more than 41,000 posts, is there any alternative way?

can you help us, in fixing this problem?

Warning: mysqli_query(): (HY000/1021): Disk full (/dev/shm/#sql_557e9_47.MAI); waiting for someone to free some space… (errno: 28 “No space left on device”) in /home/u524184193/domains/jmais.com.br/public_html/wp-includes/wp-db.php on line 2056
Erro no banco de dados do WordPress: [Disk full (/dev/shm/#sql_557e9_47.MAI); waiting for someone to free some space… (errno: 28 “No space left on device”)]
SELECT t.*, tt.* FROM wp_terms AS t INNER JOIN wp_term_taxonomy AS tt ON t.term_id = tt.term_id WHERE tt.taxonomy IN (‘nav_menu’) ORDER BY t.name ASC