mysql - Server CPU reaching 100% with less than 50 users on website (Drupal 6) -

I am having trouble with that website with which I am working, which was developed with Drupal 6 and It behaves in a weird way.

The problem is that at least 50 users, the CPU usage of the server reaches 100% (today it was at the peak of 40 users). It was crashed, with the server crashing down and the site was down as a result, but now it is slow.

Here is a server configuration:

CPU

br> Intel (R) Core (TM) 2 Duo CPU E6550 @ 2.33GHz Cache: 4096KB
RAM
2x 2048Mo
Drive: 2x 750 Go

Either way, I feel like having 50 users on this website is like 500 on a well-optimized website. As the Dopl website was increasing the number of useless queries, the website was so slow. The number of requests per minute is 3300, despite the number of users usually on the website (maximum simultaneous connection: 35).

I used mysqltuner, here is a recommended file, it can be useful:

-------- Recommendations ----- --- --------------------------------------------- General Recommendations : Optimize Run Table to defragate tables for better performance, MySQL has been started within the last 24 hours - Recommendations may be incorrect Enable slow query logs to troubleshoot bad queries to reduce connection usage L To reduce the consistent connection or eliminate indexing, always adjust your joining questions when adjusting, tmp_table_size

to adjust the variable: / max_heap_table_size LIMIT in thread 4 for thread_cache_size To increase the increase in a starting value, table_cache will gradually increase the file descriptor limit to increase the table_cache to more than 64 before it reads as less as your selection isolated query

  wait_timeout (& Lt; 28800) interactive_timeout (& lt; 28800) query_cache _size (& gt; = 8 m) join_buffer_size (& gt; 32M) with the maximum_heap_table_size (& gt; 128.0K, or always available) tmp_table_size (& gt; 16M) thread_cache_size (starting with 4) table_cache (& gt;)  

< P> I know that you may need more information to know what might be wrong with the configuration. Please ask me what is important, I will gladly edit my message to treat your message as relevant.