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masood_y · #1 01-20-2009, 07:42 AM

My server load is high in last 7 week.
Here is my server status:

System Load RAM Usage CPU Usage Requests/Sec
6.27 187.8MB 4.2% 217

How can see why cpu load is high?
Im using 2cpu license.

PSS · #2 01-20-2009, 11:02 AM

You CPU load is not high, it's only 4%. Load average (5min) is a bit high, but not abnormal.

try shell commands:

top

it shows realtime values. quit with q. Press s +2 to set 2 second sampling interval.

ps auwx

It'll show all processes and what is running them.

free -t -m

shows you memory usage in MB:s. Normally nearly all memory should be used in Linux, but swap only by a little amount (2-5% of swap size). If you're swapping a lot it will kill performance.

It's hard to say anything specific as we don't know what scripts, databases, traffic do you run, and how.

masood_y · #3 01-21-2009, 06:58 AM

I see most of cpu load is for mysql:

Pid Owner Priority Cpu % Mem % Command
13639 mysql 0 81.8 4.1 /usr/sbin/mysqld --basedir=/ --datadir=/var/lib/mysql --user=mysql --pid-file=/var/lib/mysql/giga.hostjewelry.info.pid --skip-external-locking --socket=/var/lib/mysql/mysql.sock

How can resolve this issue?

anewday · #4 01-21-2009, 07:41 AM

Your mysql is not optimized.

Bono · #5 01-21-2009, 07:43 AM

You should optimize your mysql settings.

brrr · #6 01-24-2009, 07:39 AM

MySQL is commonly the most memory and CPU consuming process on most servers. Optimizing it is always important and can pay big dividends. Google the issue and you will find plenty of good advice and resources to do that.

mysitegroup · #7 03-15-2009, 02:28 PM

I will be the IOWAIT guy.... ha ha..

What is your servers IOWAIT?

If high, mySQL will fall on it's face - with high load... and this will snowball, with excessive threads being created, and get worse and worse.

Check and fix your IOWAIT (in addition to optimizing mySQL my.cnf file).

Warm regards.

masood_y · #8 03-16-2009, 04:19 AM

I dont know what is IOWAIT, here is my curren mysql configuration.
Can you please check it?

Code:

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
skip-locking
skip-networking
safe-show-database
query_cache_limit=1M
query_cache_size=256M
query_cache_type=1
max_user_connections=200
max_connections=500
interactive_timeout=10
wait_timeout=20
connect_timeout=20
thread_cache_size=128
key_buffer=256M
join_buffer=1M
max_connect_errors=20
max_allowed_packet=16M
table_cache=1024
record_buffer=1M
sort_buffer_size=4M
read_buffer_size=4M
read_rnd_buffer_size=4M
thread_concurrency=4
myisam_sort_buffer_size=64M
server-id=1
log_slow_queries=/var/log/mysql-slow-queries.log
long_query_time=2
collation-server=latin1_general_ci

[safe_mysqld]
err-log=/var/log/mysqld.log
pid-file=/var/lib/mysql/mysql.pid
open_files_limit=8192

[mysqldump]
quick
max_allowed_packet=16M

[mysql]
no-auto-rehash
#safe-updates

[isamchk]
key_buffer=32M
sort_buffer=32M
read_buffer=16M
write_buffer=16M

[myisamchk]
key_buffer=32M
sort_buffer=32M
read_buffer=16M
write_buffer=16M

[mysqlhotcopy]
interactive-timeout

mistwang · #9 03-16-2009, 09:52 AM

Quote:

Originally Posted by mysitegroup

I will be the IOWAIT guy.... ha ha..

What is your servers IOWAIT?

If high, mySQL will fall on it's face - with high load... and this will snowball, with excessive threads being created, and get worse and worse.

Check and fix your IOWAIT (in addition to optimizing mySQL my.cnf file).

Warm regards.

One tip to reduce IOWAIT is to turn off updating access time of file system, search for "noatime" file system mount option for /etc/fstab .

masood_y · #10 03-16-2009, 10:30 AM

Can you provide more information?