Help with tuning mySQL

[Simon Lidster]

Hi,

I'm interested in tuning MySQL.

I used MySQL tuner which came back with recommendations, although I believe it's not that reliable?

I then ran through Percona config wizard which gave me a suggested my.cnf.

I don't know much about MySQL, so could someone please check out the suggested settings and let me know they are ok or not?

Server is VPS 1.5 Gb RAM, 40GB SSD, 2 CPU.

About 30 websites, mostly low to moderate traffic, all Wordpress.

Performance is good, but I like things to be run on best practices where possible.

MySQL tuner output - just for info

 >>  MySQLTuner 1.3.0 - Major Hayden 
 >>  Bug reports, feature requests, and downloads at http://mysqltuner.com/
 >>  Run with '--help' for additional options and output filtering
[OK] Logged in using credentials passed on the command line
[OK] Currently running supported MySQL version 5.5.37-cll
[OK] Operating on 64-bit architecture

-------- Storage Engine Statistics -------------------------------------------
[--] Status: +ARCHIVE +BLACKHOLE +CSV -FEDERATED +InnoDB +MRG_MYISAM 
[--] Data in MyISAM tables: 156M (Tables: 1078)
[--] Data in InnoDB tables: 151M (Tables: 1181)
[--] Data in PERFORMANCE_SCHEMA tables: 0B (Tables: 17)
[!!] Total fragmented tables: 106

-------- Security Recommendations  -------------------------------------------
[OK] All database users have passwords assigned

-------- Performance Metrics -------------------------------------------------
[--] Up for: 1d 1h 54m 24s (2M q [29.045 qps], 22K conn, TX: 9B, RX: 453M)
[--] Reads / Writes: 93% / 7%
[--] Total buffers: 81.0M global + 2.8M per thread (151 max threads)
[OK] Maximum possible memory usage: 496.2M (33% of installed RAM)
[OK] Slow queries: 0% (52/2M)
[OK] Highest usage of available connections: 19% (30/151)
[OK] Key buffer size / total MyISAM indexes: 8.0M/22.5M
[OK] Key buffer hit rate: 98.7% (18M cached / 235K reads)
[!!] Query cache is disabled
[OK] Sorts requiring temporary tables: 0% (0 temp sorts / 471K sorts)
[!!] Joins performed without indexes: 1086
[!!] Temporary tables created on disk: 38% (229K on disk / 595K total)
[!!] Thread cache is disabled
[!!] Table cache hit rate: 0% (400 open / 1M opened)
[OK] Open file limit used: 10% (520/5K)
[OK] Table locks acquired immediately: 99% (3M immediate / 3M locks)
[!!] InnoDB  buffer pool / data size: 41.0M/151.2M
[OK] InnoDB log waits: 0
-------- Recommendations -----------------------------------------------------
General recommendations:
    Run OPTIMIZE TABLE to defragment tables for better performance
    Enable the slow query log to troubleshoot bad queries
    Adjust your join queries to always utilize indexes
    When making adjustments, make tmp_table_size/max_heap_table_size equal
    Reduce your SELECT DISTINCT queries without LIMIT clauses
    Set thread_cache_size to 4 as a starting value
    Increase table_cache gradually to avoid file descriptor limits
    Read this before increasing table_cache over 64: http://bit.ly/1mi7c4C
Variables to adjust:
    query_cache_size (>= 8M)
    join_buffer_size (> 128.0K, or always use indexes with joins)
    tmp_table_size (> 16M)
    max_heap_table_size (> 16M)
    thread_cache_size (start at 4)
    table_cache (> 400)
    innodb_buffer_pool_size (>= 151M)

Percona suggestions - these are the ones I'm interested in implementing.

# Generated by Percona Configuration Wizard (http://tools.percona.com/) version REL5-20120208
# Configuration name webhost generated for [email protected] at 2014-09-25 07:10:03

[mysql]

# CLIENT #
port                           = 3306
socket                         = /var/lib/mysql/mysql.sock

[mysqld]

# GENERAL #
user                           = mysql
default-storage-engine         = InnoDB
socket                         = /var/lib/mysql/mysql.sock
pid-file                       = /var/lib/mysql/mysql.pid

# MyISAM #
key-buffer-size                = 32M
myisam-recover                 = FORCE,BACKUP

# SAFETY #
max-allowed-packet             = 16M
max-connect-errors             = 1000000

# DATA STORAGE #
datadir                        = /var/lib/mysql/

# BINARY LOGGING #
log-bin                        = /var/lib/mysql/mysql-bin
expire-logs-days               = 14
sync-binlog                    = 1

# CACHES AND LIMITS #
tmp-table-size                 = 32M
max-heap-table-size            = 32M
query-cache-type               = 0
query-cache-size               = 0
max-connections                = 500
thread-cache-size              = 50
open-files-limit               = 65535
table-definition-cache         = 4096
table-open-cache               = 4096

# INNODB #
innodb-flush-method            = O_DIRECT
innodb-log-files-in-group      = 2
innodb-log-file-size           = 128M
innodb-flush-log-at-trx-commit = 1
innodb-file-per-table          = 1
innodb-buffer-pool-size        = 1G

# LOGGING #
log-error                      = /var/lib/mysql/mysql-error.log
log-queries-not-using-indexes  = 1
slow-query-log                 = 1
slow-query-log-file            = /var/lib/mysql/mysql-slow.log

 

[cPanelMichael]

Hello

I have moved this thread to our "Optimization" forum. You should receive more user-feedback here.

Thank you.

 

[Simon Lidster]

Contents of my.cnf

[mysqld]
innodb_file_per_table=1
max_allowed_packet=268435456
open_files_limit=5000
innodb_buffer_pool_size=42991616

 

[Archmactrix]

I suggest that you increase the buffer pool value like the Percona Configuration Wizard report suggested. But I'm not sure if it's ok to use the 1GB value. It want hurt now, but it could hurt later on if your server has use for it but not enough RAM. So I suggest that you start with a much lower value of 256 MB or 512 MB. If you add more RAM to your server than you can increase this value further.

You can use the suggested value for the key buffer size of 32MB
You can also use the suggested value for the table open cache of 4096

I suggest that you enable thread cache but I'm not sure if it's safe or recommendable to start with the Percona Configuration Wizard suggested value of 50. You could start with a much lower value or like 4 or 8.

Watch this and see how this performs.

table-open-cache=4096
innodb_buffer_pool_size=256M
key_buffer_size=32M
thread_cache_size=4
table-open-cache=4096

 

[Simon Lidster]

Archmactrix, thanks very much for this.

I'll check the performance in a week.