im running a clearOS server on my local network (small company of 10 developers) we use it as a developement server to test our work and show it to clients in test process each developer has a unique username and password to access the ftp/http/smb.
the problem is when one of the developer runs a non safe code (lets assume it is a php code) like running a infinite loop! the server completely crashes for all and im not able to identify who is the the faulty developer!! how can that be solved ? thanks in advance

**My server's info**

1. clearOS server
2. RAM 16GB
3. SSD 1TB (2 partitions)

**Apps installed:**

1. proftpd,
2. gitlab,
3. apache,
4. mariadb

**Users:** 

1. physical root user and
2. 10 virtual user (using ldap) 
*each user has a unique password*