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What should I fix to optimize my mysql?

clove28

Active member
#1
Hi,

I used mysqltuner to check the problem related to frequent crashes of my database. I received this warning

*** MySQL's maximum memory usage is dangerously high ***


Here's the result of mysqltuner:

Code:
>>  MySQLTuner 1.4.0 - Major Hayden <major@mhtx.net>
>>  Bug reports, feature requests, and downloads at http://mysqltuner.com/
>>  Run with '--help' for additional options and output filtering
Please enter your MySQL administrative login:
Please enter your MySQL administrative password:
[OK] Currently running supported MySQL version 5.5.42-log
[OK] Operating on 64-bit architecture

-------- Storage Engine Statistics -------------------------------------------
[--] Status: +ARCHIVE +BLACKHOLE +CSV -FEDERATED +InnoDB +MRG_MYISAM
[--] Data in MyISAM tables: 51M (Tables: 3)
[--] Data in InnoDB tables: 653M (Tables: 233)
[--] Data in PERFORMANCE_SCHEMA tables: 0B (Tables: 17)
[--] Data in MEMORY tables: 372K (Tables: 5)
[!!] Total fragmented tables: 34

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

-------- Performance Metrics -------------------------------------------------
[--] Up for: 34m 50s (46K q [22.025 qps], 3K conn, TX: 3B, RX: 18M)
[--] Reads / Writes: 86% / 14%
[--] Total buffers: 672.0M global + 2.8M per thread (500 max threads)
[!!] Maximum possible memory usage: 2.0G (205% of installed RAM)
[OK] Slow queries: 4% (1K/46K)
[OK] Highest usage of available connections: 1% (6/500)
[OK] Key buffer size / total MyISAM indexes: 32.0M/51.3M
[OK] Key buffer hit rate: 98.8% (55K cached / 675 reads)
[!!] Query cache is disabled
[OK] Sorts requiring temporary tables: 0% (0 temp sorts / 1K sorts)
[!!] Joins performed without indexes: 8
[OK] Temporary tables created on disk: 22% (103 on disk / 455 total)
[OK] Thread cache hit rate: 99% (6 created / 3K connections)
[OK] Table cache hit rate: 33% (142 open / 420 opened)
[OK] Open file limit used: 0% (56/65K)
[OK] Table locks acquired immediately: 99% (70K immediate / 70K locks)
[!!] InnoDB  buffer pool / data size: 592.0M/653.4M
[OK] InnoDB log waits: 0
-------- Recommendations -----------------------------------------------------
General recommendations:
    Run OPTIMIZE TABLE to defragment tables for better performance
    MySQL started within last 24 hours - recommendations may be inaccurate
    Reduce your overall MySQL memory footprint for system stability
    Adjust your join queries to always utilize indexes
Variables to adjust:
  *** MySQL's maximum memory usage is dangerously high ***
  *** Add RAM before increasing MySQL buffer variables ***
    query_cache_size (>= 8M)
    join_buffer_size (> 128.0K, or always use indexes with joins)
    innodb_buffer_pool_size (>= 653M)
And here's my my.cnf config.

Code:
# Generated by Percona Configuration Wizard (http://tools.percona.com/) version REL5-20120208
# Configuration name server generated for .......

[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
performance_schema             = off

# MyISAM #
key-buffer-size                = 10M
myisam-recover                 = FORCE,BACKUP

# SAFETY #
max-allowed-packet             = 10M
max-connect-errors             = 1000000
skip-name-resolve
sql-mode                       = STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_AUTO_VALUE_ON_ZERO,NO_ENGINE_SUBSTITUTION,NO_ZERO_DATE,NO_ZERO_IN_DATE,ONLY_FULL_GROUP_BY
sysdate-is-now                 = 1
innodb                         = FORCE

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

# BINARY LOGGING #
log-bin                        = /var/lib/mysql/mysql-bin
expire-logs-days               = 7
sync-binlog                    = 1

# CACHES AND LIMITS #
tmp-table-size                 = 20M
max-heap-table-size            = 32M
query-cache-type               = 1
query-cache-size               = 32M
max-connections                = 50
thread-cache-size              = 50
open-files-limit               = 1500
table-definition-cache         = 4096
table-open-cache               = 4096

# INNODB #
innodb-flush-method            = O_DIRECT
innodb-log-files-in-group      = 2
innodb-log-file-size           = 80M
innodb-flush-log-at-trx-commit = 1
innodb-file-per-table          = 1
innodb-buffer-pool-size        = 700M

# 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
I hope someone could help me.

Thanks! :)
 
#2
U should increase innodb buffer pool size but one thing I noticed which looks like odd is:

mysqltuner says you got max connections to 500 but your config says it's set to 50. Did you run tuner script after changing my.cnf?

Also uptime is just 34 mins. I would suggest to run tuner scripts at least after 1 day of up-time so you get more useful avg data rather then initial ones.