Troubleshooting of MySQLTuner

"MySQLTuner is a script written in Perl that will assist you with your MySQL configuration and make recommendations for increased performance and stability."

How to resolve: (Cygwin) couldn't find diagnostic data[edit]

Condition:

$ perl mysqltuner.pl
couldn't find diagnostic data in /usr/share/perl5/5.26/pods/perldiag.pod /usr/local/lib/perl5/site_perl/5.26/x86_64-cygwin-threads /usr/local/share/perl5/site_perl/5.26 /usr/lib/perl5/vendor_perl/5.26/x86_64-cygwin-threads /usr/share/perl5/vendor_perl/5.26 /usr/lib/perl5/5.26/x86_64-cygwin-threads /usr/share/perl5/5.26 mysqltuner.pl at /usr/share/perl5/5.26/diagnostics.pm line 259, <POD_DIAG> line 711.
Compilation failed in require at mysqltuner.pl line 45.
BEGIN failed--compilation aborted at mysqltuner.pl line 45.

Solution:

Download the Cygwin installation file setup-x86_64.exe from Cygwin Installation
Install the perl_pods package using either method below:

Method 1: Using Cygwin Setup Window (GUI)

Double-click setup-x86_64.exe to launch the setup wizard
Follow the installation wizard until you reach the "Select Packages" screen
If the view dropdown shows "Pending", change it to "Full" to see all available packages
Search for "perl_pods" in the search box
Click on the "Skip" text next to perl_pods to change it to the version number (this selects it for installation)
Click "Next" to proceed with the installation

Method 2: Using Command Line (CMD)^[1]^[2]

Open a command line window
Navigate to the directory containing setup-x86_64.exe, for example: cd C:\Downloads, then press Enter
Enter the following command: setup-x86_64.exe -q -P "perl_pods"

Environment:

Windows 2008 R2 standard
Cygwin version: CYGWIN_NT-6.1 Win2008R2-0-0 2.9.0(0.318/5/3) 2017-09-12 10:18 x86_64 Cygwin (information returned from uname -a)

How to resolve: (Cygwin) wget command not found[edit]

Condition: When I tried to download the MySQLTuner using wget command but met the error.

Solution:

Download the installation file setup-x86_64.exe of Cygwin from Cygwin Installation
Open the command line window
Change to the directory where the file setup-x86_64.exe located e.g. cd C:\Downloads> and than press the key Enter
To install the packages: wget. Keyin setup-x86_64.exe -q -P "wget" or follow the steps on terminal - WGET Command Not Working in Cygwin - Super User if you prefer the GUI window.

How to resolve: (Cygwin) unzip: command not found[edit]

Condition:

$ unzip -l sysschema.zip
-bash: unzip: command not found

Solution:

Download the installation file setup-x86_64.exe of Cygwin from Cygwin Installation
Open the command line window
Change to the directory where the file setup-x86_64.exe located e.g. cd C:\Downloads> and than press the key Enter
To install the packages: unzip. Keyin setup-x86_64.exe -q -P unzip

How to resolve: Attempted to use login credentials, but they were invalid.[edit]

Condition:

$ perl mysqltuner.pl
 >>  MySQLTuner 1.7.5 - Major Hayden <[email protected]>
 >>  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: root
Please enter your MySQL administrative password: [!!] Attempted to use login credentials, but they were invalid.

Solution:

Specify the host parameter to command line e.g. perl mysqltuner.pl --host 127.0.0.1
Check the typo of mysql account and password

How to resolve: Performance schema should be activated for better diagnostics[edit]

Condition:

$ perl mysqltuner.pl
-------- Recommendations ---------------------------------------------------------------------------
General recommendations:
    Performance schema should be activated for better diagnostics

Solution:

Verify the MySQL setting. Execute the SQL query SHOW VARIABLES LIKE 'performance_schema'. The result should be OFF.
Stop the MySQL service.
Open the MySQL configuration file named my.ini on Win or my.cnf on Linux The file maybe located in different path e.g. C:\xampp\mysql\bin\my.ini on Win
Edit the MySQL configuration file