Owncloud/MariaDB Server tunning

Job ID: 32192812

Budget: $30 – $250 USD

I have a server with Owncloud with MariaDB that is having high CPU load during high usage in Centos 7.
I haven't been able to improve the performance.
The server's TOP on high load is usually 40,35,29 and the file sync becomes really slow and unsuccessful between the owncloud clients and the server.
I need someone with extensive knowledge in maintaining an owncloud structure to help me fix the resource problems on the server.
Server is Centos 7, with owncloud 10.7.0.4 Community edition.
Hardware is 8 core, 12GB RAM, 2TB HD VM machine.
The server is accessed by 30 owncloud Windows clients.
System works fine until the server load goes high and becomes laggy and really slow.
The person that applies for this must be an expert in Linux, MariaDB and owncloud. If any of these are missing do not apply for job.
Server is running and working fine so no installation is needed, only tweaking of MariaDB, apache and owncloud to make the server work fine under heavy load.
Related categories: Linux Apache MariaDB CentOs