Overload on web hosting, by vB or high traffic?

[Mattwhf]

Hello

Sometimes I got this alert "The system load average is 17.08" in Message System on my web hosting forum http://forumweb.hosting , I tried to find the reasons in log files but have no lucks.

this is the details

This is an automated message notifying you that the 5 minute load average on your system is 17.08.
This has exceeded the 10 threshold.

One Minute - 63.7
Five Minutes - 17.08
Fifteen Minutes - 5.81

top - 21:47:02 up 17 days, 3:44, 0 users, load average: 63.70, 17.08, 5.81
Tasks: 337 total, 74 running, 263 sleeping, 0 stopped, 0 zombie
%Cpu(s): 3.7 us, 0.6 sy, 0.0 ni, 95.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.4 st
KiB Mem : 2916052 total, 291512 free, 2468816 used, 155724 buff/cache
KiB Swap: 1048572 total, 163640 free, 884932 used. 285744 avail Mem

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
22272 mysql 20 0 1138612 273872 1112 S 56.5 9.4 1649:49 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --log-error=/var/lib/mysql/server.forumweb.hosting.err --pid-file=server.forumweb.hosting.pid
9944 webmast+ 20 0 187524 13952 3552 R 13.0 0.5 0:00.21 /usr/sbin/httpd -k start
9701 apache 20 0 192592 17580 2372 S 8.7 0.6 0:00.52 /usr/sbin/httpd -k start
9862 webmast+ 20 0 193856 18396 2616 R 8.7 0.6 0:00.19 /usr/sbin/httpd -k start
9935 apache 20 0 187524 12880 2504 S 8.7 0.4 0:00.19 /usr/sbin/httpd -k start
9937 apache 20 0 190016 15612 2720 S 8.7 0.5 0:00.21 /usr/sbin/httpd -k start
9996 webmast+ 20 0 192064 17668 2728 R 8.7 0.6 0:00.23 /usr/sbin/httpd -k start
10010 apache 20 0 189760 15356 2720 S 8.7 0.5 0:00.16 /usr/sbin/httpd -k start
48 root 20 0 0 0 0 S 4.3 0.0 3:10.25 [kswapd0]
9674 webmast+ 20 0 191552 12868 1940 S 4.3 0.4 0:00.31 /usr/sbin/httpd -k start
9688 webmast+ 20 0 193856 11224 2620 D 4.3 0.4 0:00.26 /usr/sbin/httpd -k start
9694 webmast+ 20 0 193856 11224 2604 D 4.3 0.4 0:00.61 /usr/sbin/httpd -k start
9700 webmast+ 20 0 193856 10304 2236 D 4.3 0.4 0:00.21 /usr/sbin/httpd -k start
9703 webmast+ 20 0 193856 9976 1964 D 4.3 0.3 0:00.23 /usr/sbin/httpd -k start
9730 webmast+ 20 0 193600 13768 2604 D 4.3 0.5 0:00.18 /usr/sbin/httpd -k start
9737 webmast+ 20 0 193600 13020 2616 R 4.3 0.4 0:00.20 /usr/sbin/httpd -k start
9740 webmast+ 20 0 193600 13316 2604 R 4.3 0.5 0:00.19 /usr/sbin/httpd -k start
9743 webmast+ 20 0 193856 14280 2612 D 4.3 0.5 0:00.21 /usr/sbin/httpd -k start
9745 webmast+ 20 0 193856 13668 2612 R 4.3 0.5 0:00.21 /usr/sbin/httpd -k start
9748 webmast+ 20 0 193856 13844 2608 D 4.3 0.5 0:00.21 /usr/sbin/httpd -k start
9788 webmast+ 20 0 193856 12544 2020 R 4.3 0.4 0:00.17 /usr/sbin/httpd -k start
9792 webmast+ 20 0 194112 14220 2640 R 4.3 0.5 0:00.26 /usr/sbin/httpd -k start
9795 webmast+ 20 0 193856 14136 2604 R 4.3 0.5 0:00.22 /usr/sbin/httpd -k start

Can any one know which made my hosting overload? by vB or high traffic or ddos attacks?

Thanks