Mysql Config Optimization Suggestion - php

Question

I have server with 8 GB RAM and 8 Core, Running one website, I have done mysql configuration setting, on which server working normally, but in some times (1 to 2 times in 24 hours), it takes so much load. Os running CentOS
Need suggestion.
[mysqld]
connection settings
max_connect_errors=10
max_connections=500
max_user_connections=700
wait_timeout=60
connect_timeout=10
interactive_timeout=60
innodb_buffer_pool_size=6GB
cache settings
query_cache_limit=128M
query_cache_size=10M
query_cache_type=1
table_open_cache=5000
thread_cache_size=250
buffer sizes
key_buffer=1288M
sort_buffer_size=20M
read_buffer_size=20M
join_buffer_size=20M
tmpdir / temp table sizes
tmp_table_size=256M
max_heap_table_size=256M
misc. settings
default-storage-engine = MYISAM
datadir=/var/lib/mysql
skip-external-locking
server-id = 1
open-files-limit = 96384
max_allowed_packet = 300M
innodb settings
innodb_data_file_path = ibdata1:10M:autoextend
innodb_thread_concurrency = 10
innodb_buffer_pool_size = 1000M
innodb_log_buffer_size = 500M
innodb_file_per_table = 1
[mysqld_safe]
open-files-limit = 16384
[mysqldump]
quick
max_allowed_packet=600M
[myisamchk]
key_buffer = 128M
sort_buffer = 128M
read_buffer = 128M
write_buffer = 16M
[mysql]
no-auto-rehash

Answer 1

Right now you have assigned more RAM to mysql than you have physically on server. Please check my comment below against variables-
[mysqld]
#connection setting
max_connect_errors=10
max_connections=500 #each connection consumes server resources, so keep how many required.
max_user_connections=700 #It should be always less than max_connections,even you should remove it.
wait_timeout=60
connect_timeout=10
interactive_timeout=60
innodb_buffer_pool_size=6GB #duplicate as already mentioned below
#cache setting
query_cache_limit=128M #this should be less than query_cache_size, 2M will be sufficient we should not cache heavy queries as it will slow the process.
query_cache_size=10M #can keep 20M or increase as per requirement.
query_cache_type=1
table_open_cache=5000
thread_cache_size=250 --even not impact much to performance but still should not more than 100.
#buffer sizes
key_buffer=1288M # keep it 20M as your server is innodb
sort_buffer_size=20M #this variable consumes server resources for each connection, 2M should be sufficient but can increase based on your queries.
read_buffer_size=20M #this variable consumes server resources for each connection, 2M should be sufficient but can increase based on your queries.
join_buffer_size=20M #this variable consumes server resources for each connection, 2M should be sufficient but can increase based on your queries.
#tmpdir / temp table sizes
tmp_table_size=256M
max_heap_table_size=256M
#misc. settings
default-storage-engine = MYISAM # change to innoDB
datadir=/var/lib/mysql
skip-external-locking
server-id = 1
open-files-limit = 96384
max_allowed_packet = 300M # You can reduce it to 64M or how much really required, fine if your application is sending large packet.
#innodb settings
innodb_data_file_path = ibdata1:10M:autoextend
innodb_thread_concurrency = 0 #mysql can utilize it better read this > http://dba.stackexchange.com/questions/5666/possible-to-make-mysql-use-more-than-one-core
innodb_buffer_pool_size = 1000M # It should be how much you can increase in innodb upto 80% of RAM.
innodb_log_buffer_size = 500M #8M is fine can increase as per server write in your environment but not 500M, as consumes server resources based on no of connections.
innodb_file_per_table = 1
[mysqld_safe]
log-error=/var/log/mysql/mysqld.log
[mysqldump]
quick
Note: You can leave other sections except [mysqld], [mysqld_Safe] nd [mysqldump]
Finally you can test your server with below configuration-
[mysqld]
#connection setting
max_connect_errors=10
max_connections=400
wait_timeout=60
connect_timeout=10
interactive_timeout=60
#cache setting
query_cache_limit=2M
query_cache_size=50M
query_cache_type=1
table_open_cache=5000
thread_cache_size=100
#buffer sizes
key_buffer_size=20M
sort_buffer_size=2M
read_buffer_size=2M
join_buffer_size=2M
#tmpdir / temp table sizes
tmp_table_size=256M
max_heap_table_size=256M
#misc. settings
default-storage-engine = innoDB
datadir=/var/lib/mysql
skip-external-locking
server-id = 1
open-files-limit = 65535
max_allowed_packet = 64M
#innodb settings
innodb_data_file_path = ibdata1:10M:autoextend
innodb_thread_concurrency = 0
innodb_buffer_pool_size = 4G
innodb_log_buffer_size = 8M
innodb_file_per_table = 1
[mysqldump]
quick
Note: If you can reduce total_connections then you can increase innodb_buffer_pool_size and can get better performance. with 250 users you can increase innodb_buffer_pool_size from 4GB to 5GB.
Still first you need to test your server and can +/- as per requirement/performance.