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100% cpu usage on single cpu core
Posted by: ds sd ()
Date: December 15, 2009 04:53AM

Hi all,

I really need your help on finding the solution for my problems. Fyi, i'm using 2 X quad core processor with 8gb of RAM. This server is a dedicated database server. So, my problems are, the mysql process always use 1 cpu core at 1 time and it used 100% of the cpu resource. I'am not sure why it happen like it. Below are my server 'TOP' status, as you can see cpu4 use 100% usage while others like at idle state.


top - 18:27:53 up 103 days, 7:14, 3 users, load average: 1.10, 1.07, 1.02
Tasks: 191 total, 1 running, 190 sleeping, 0 stopped, 0 zombie
Cpu0 : 0.0% us, 0.3% sy, 0.0% ni, 99.7% id, 0.0% wa, 0.0% hi, 0.0% si
Cpu1 : 0.0% us, 0.0% sy, 0.0% ni, 99.3% id, 0.7% wa, 0.0% hi, 0.0% si
Cpu2 : 0.3% us, 0.0% sy, 0.0% ni, 99.7% id, 0.0% wa, 0.0% hi, 0.0% si
Cpu3 : 0.0% us, 0.0% sy, 0.0% ni, 98.6% id, 1.4% wa, 0.0% hi, 0.0% si
Cpu4 : 100.0% us, 0.0% sy, 0.0% ni, 0.0% id, 0.0% wa, 0.0% hi, 0.0% si
Cpu5 : 0.0% us, 0.0% sy, 0.0% ni, 100.0% id, 0.0% wa, 0.0% hi, 0.0% si
Cpu6 : 0.0% us, 0.0% sy, 0.0% ni, 100.0% id, 0.0% wa, 0.0% hi, 0.0% si
Cpu7 : 0.0% us, 0.0% sy, 0.0% ni, 99.7% id, 0.3% wa, 0.0% hi, 0.0% si
Mem: 8165752k total, 8077196k used, 88556k free, 493192k buffers
Swap: 4096532k total, 276k used, 4096256k free, 6326856k cached

PID USER PR NI %CPU TIME+ %MEM VIRT RES SHR S COMMAND
11395 mysql 16 0 100 39700:41 2.2 706m 172m 4764 S mysqld


Below is my.cnf configuration file

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package)
old_passwords=1
skip-locking
key_buffer = 384M
max_allowed_packet = 1M
table_cache = 512
sort_buffer_size = 2M
read_buffer_size = 2M
read_rnd_buffer_size = 8M
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size = 32M
log_queries_not_using_indexes = On
log_slow_queries=/var/lib/mysql/log-slow-queries.log

innodb_data_home_dir = /var/lib/mysql/
#innodb_data_file_path = ibdata1:100M:autoextend
set-variable = innodb_buffer_pool_size=100M
set-variable = innodb_additional_mem_pool_size=10M
innodb_flush_log_at_trx_commit=1

#skip-innodb
skip-name-resolve
# Try number of CPU's*2 for thread_concurrency
thread_concurrency = 16
set-variable=max_connections=2000

[mysql.server]
user=mysql
basedir=/var/lib

[mysqld_safe]
err-log=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

[isamchk]
key_buffer = 256M
sort_buffer_size = 256M
read_buffer = 2M
write_buffer = 2M

[myisamchk]
key_buffer = 256M
sort_buffer_size = 256M
read_buffer = 2M
write_buffer = 2M

[mysqlhotcopy]
interactive-timeout

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Subject Views Written By Posted
100% cpu usage on single cpu core 5930 ds sd 12/15/2009 04:53AM
Re: 100% cpu usage on single cpu core 2378 Rick James 12/17/2009 12:27AM
Re: 100% cpu usage on single cpu core 2446 Gus Lopez 12/23/2009 04:34PM
Re: 100% cpu usage on single cpu core 2146 Gus Lopez 12/23/2009 04:49PM
Re: 100% cpu usage on single cpu core 2048 Gus Lopez 12/23/2009 06:07PM
Re: 100% cpu usage on single cpu core 2753 Rick James 12/23/2009 08:52PM
Re: 100% cpu usage on single cpu core 1978 Gus Lopez 12/23/2009 09:53PM
Re: 100% cpu usage on single cpu core 2225 Rick James 12/24/2009 03:48PM


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