Question regarding my.cnf optimization

[Rakaris Bakaris]

Hello!
I'm trying to optimize SQL performance, so I need a little help to do the task. The server is virtualized and it has 6 Cores CPU, 8GB RAM. Server is running on SAS disks (there are no disk ques since server has deployed) and /var/lib/mysql directory size is about 28GB.

The server has the following MySQL configuration:
pastebin.com/FWTNU80A

After running mysqltuner.pl I got the following results:
pastebin.com/XgVY45qb
From report we can see that max_connections needs to be adjusted (seems that value 85 will be ok because average value is around 40).
So I have questions:

1) mysqltuner suggests:
a) innodb_buffer_pool_size (>= 13G) if possible. Now it has 3.5GB configured. According to mysqlcalculator.com maximal memory usage will be too large if I increase the value. Do I need to decrease innodb_buffer_pool_instances?
b) suggest the following parameters increase:

join_buffer_size (> 20.0M, or always use indexes with joins)
tmp_table_size (> 96M)
max_heap_table_size (> 50M)
table_open_cache (> 3800)​

According mysqlcalculator maximal memory usage will be too large if I increase the value.
so the question: how to determine the best compromise for these parameters? Do I need to reduce innodb_buffer_pool_size and increase some of the parameters from (point 1.b)

2) Seems the parameter wait_timeout and interactive_timeout has wrongly set up. How to determine the best value?

3) innodb_log_file_size * innodb_log_files_in_group should be equals to 1/4 of buffer pool size (=1G) if possible. How much impact on performance will give the change of the log file size?
Question: is the procedure bellow procedure correct for Cpanel server?
percona.com/blog/2011/07/09/how-to-change-innodb_log_file_size-safely/

Do you have other comments / suggestions?
Than you in advance.
P.S. - seems the topic more covers Database Discussions category so please move it to the Forum's Databases Discussions category.

 

[cPanelMichael]

Hello,

Advice about tuning specific configuration values typically requires the help of a qualified system administrator. I'll leave this thread open for additional user-feedback, but I did want to note the "mysqladmin processlist" command is helpful if you are noticing bad MySQL performance. The command can help determine if any specific databases are responsible for the poor performance.

You can also find a list of companies offering system administration services if you do not receive sufficient user-feedback to this thread:

System Administration Services | cPanel Forums

Thank you.