mysql process constantly overload - mysql

Question

i properly asking a question that do not have an answer, but i am out of resources and have to try any mean that possible to have a way to solve this problem. first off. i ain't programmer, i just an online store staff that assign to deal with the server and stuff like that. i have basic knowledge to cpanel, whm, but no experience in programming.
we see our server is very very slow recently, i go in whm and see the cpu usage constantly stay like 200% up to 2000% (yes, 2000%) from time to time, then i looked into the process manager and see one particular line that border me:
pid991 - this use like at least 100% of the cpu most of the time i look and the command is
/usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/lib/mysql/www.(domain).com.err --pid-file=/var/lib/mysql/www.(domain).com.pid
and if i go into trace, i see this code repeat again and again
>fcntl(12, F_GETFL) = 0x2 (flags O_RDWR)
>fcntl(12, F_SETFL, O_RDWR|O_NONBLOCK) = 0
>accept(12, {sa_family=AF_FILE, NULL}, [2]) = 95
>fcntl(12, F_SETFL, O_RDWR) = 0
>getsockname(95, {sa_family=AF_FILE, path="/var/lib/mysql/mysql.sock"}, [28]) = 0
>gettimeofday({1380692546, 638961}, NULL) = 0
>fcntl(95, F_SETFL, O_RDONLY) = 0
>fcntl(95, F_GETFL) = 0x2 (flags O_RDWR)
>setsockopt(95, SOL_SOCKET, SO_RCVTIMEO, "\36\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 0
>setsockopt(95, SOL_SOCKET, SO_SNDTIMEO, "<\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 0
>fcntl(95, F_SETFL, O_RDWR|O_NONBLOCK) = 0
>setsockopt(95, SOL_IP, IP_TOS, [8], 4) = -1 EOPNOTSUPP (Operation not supported)
>gettimeofday({1380692546, 641571}, NULL) = 0
>clone(child_stack=0x7ff0ead58ff0, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, parent_tidptr=0x7ff0ead599d0, tls=0x7ff0ead59700, child_tidptr=0x7ff0ead599d0) = 6590
>poll([{fd=10, events=POLLIN}, {fd=12, events=POLLIN}], 2, -1) = 1 ([{fd=12, revents=POLLIN}])
with only difference in the number string and may be some ids. i actually have a programmer here, but he is a freelancer and keep tell us he doesn't know what happen, so...
can we know what this is doing with only these repeat lines of ode?
there is a kill button in process manager, is it safe to simply kill the process?
thank you for your help!

Answer 1

The trace messages do not identify the cause of your performance problem. See https://serverfault.com/questions/374120/setsockopt-eopnotsupp-operation-not-supported
It's not safe to simply kill that process; that is your MySQL database, so I expect that if you kill the process, your website will go down.
It's quite likely that you have long-running queries or just a huge volume of database activity on that server, so you'll need to investigate in that direction rather than in the trace. Start with SHOW PROCESSLIST in the MySQL console to see what's currently running and for how long, and that should point you in the direction of statements and connections to look at.