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MySQLTuner is a script written in Perl that will assist you with your MySQL configuration and make recommendations for increased performance and stability.
Perl Smarty Shell
Branch: master

Merge pull request #128 from ravage84/patch-2

Change anonymous account recommendation to plural
latest commit fa5a006240
@jmrenouard jmrenouard authored


Build Status - Master

MySQLTuner is a script written in Perl that allows you to review a MySQL installation quickly and make adjustments to increase performance and stability. The current configuration variables and status data is retrieved and presented in a brief format along with some basic performance suggestions.


  • MySQL 5.7 (partial support)
  • MySQL 5.6 (full support)
  • MariaDB 10.0 (full support)
  • MariaDB 10.1 (partial support)
  • MySQL 5.5 (full support)
  • MySQL 5.1 (full support)
  • MySQL 3.23, 4.0, 4.1, 5.0, 5.1 (full support)
  • Perl 5.6 or later (with perl-doc package)
  • Unix/Linux based operating system (tested on Linux, BSD variants, and Solaris variants)
  • Windows is not supported at this time (Help wanted !!!!!)
  • Unrestricted read access to the MySQL server (OS root access recommended for MySQL < 5.1)


It is extremely important for you to fully understand each change you make to a MySQL database server. If you don't understand portions of the script's output, or if you don't understand the recommendations, you should consult a knowledgeable DBA or system administrator that you trust. Always test your changes on staging environments, and always keep in mind that improvements in one area can negatively affect MySQL in other areas.

Seriously - please review the FAQ section below.

What MySQLTuner is checking exactely ?

All checks done by MySQLTuner are documented in MySQLTuner Internals documentation.


You can download the entire repository by using 'git clone' followed by the cloning URL above. The simplest and shortest method is:

wget -O
wget -O basic_passwords.txt

Of course, you can add the execute bit (chmod +x so you can execute it without calling perl directly.

Specific usage

Usage: Minimal usage locally


Usage: Minimal usage remotely

perl --host targetDNS_IP --user admin_user --password admin_password

Usage: Enable maximum output information around MySQL/MariaDb without debugging

perl --buffers --dbstat --idxstat

Usage: Write your result in a file with information displayed

perl --outputfile /tmp/result_mysqltuner.txt

Usage: Write your result in a file without outputting information

perl --silent --outputfile /tmp/result_mysqltuner.txt

Usage: Using template model to customize your reporting file based on Text::Template syntax.

perl --silent --reportfile /tmp/result_mysqltuner.txt --template=/tmp/mymodel.tmpl

Usage: Enable debugging information

perl --debug


Question: Will MySQLTuner fix my slow MySQL server?

No. MySQLTuner is a read only script. It won't write to any configuration files, change the status of any daemons, or call your mother to wish her a happy birthday. It will give you an overview of your server's performance and make some basic recommendations about improvements that you can make after it completes. Make sure you read the warning above prior to following any recommendations.

Question: Can I fire my DBA now?

MySQLTuner will not replace your DBA in any form or fashion. If your DBA constantly takes your parking spot and steals your lunch from the fridge, then you may want to consider it - but that's your call.

Question: Why does MySQLTuner keep asking me the login credentials for MySQL over and over?

The script will try its best to log in via any means possible. It will check for ~/.my.cnf files, Plesk password files, and empty password root logins. If none of those are available, then you'll be prompted for a password. If you'd like the script to run in an automated fashion without user intervention, then create a .my.cnf file in your home directory which contains:


Once you create it, make sure it's owned by your user and the mode on the file is 0600. This should prevent the prying eyes from getting your database login credentials under normal conditions. If a T-1000 shows up in a LAPD uniform and demands your database credentials, you won't have much of an option.

Question: Is there another way to secure credentials on latest MySQL and MariaDB distributions ?

You could use mysql_config_editor utilities.

$ mysql_config_editor set --login-path=client --user=someusername --password --host=localhost
Enter passord: ********

At this time, ~/.mylogin.cnf has been written with appropriated rigth access.

To get information about stored credentials, use the following command:

$mysql_config_editor print
user = someusername
password = *****
host = localhost

Question: It's not working on my OS! What gives?!

These kinds of things are bound to happen. Here are the details I need from you in order to research the problem thoroughly:

  • OS and OS version
  • Architecture (x86, x86_64, IA64, Commodore 64)
  • Exact MySQL version
  • Where you obtained your MySQL version (OS package, source, etc)
  • The full text of the error
  • A copy of SHOW VARIABLES and SHOW GLOBAL STATUS output (if possible)

MySQLTuner needs you

MySQLTuner needs contributors for documentation, code and feedbacks..

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