Editing Troubleshooting of MySQLTuner

"[https://github.com/major/MySQLTuner-perl MySQLTuner] is a script written in Perl that will assist you with your MySQL configuration and make recommendations for increased performance and stability."

__TOC__

== How to resolve: (Cygwin) couldn't find diagnostic data ==
Condition:
<pre>
$ 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.
</pre>

Solution:
# Download the Cygwin installation file {{kbd | key=<nowiki>setup-x86_64.exe</nowiki>}} from [https://cygwin.com/install.html Cygwin Installation]
# Install the perl_pods package using either method below:

'''Method 1: Using Cygwin Setup Window (GUI)'''
# Double-click {{kbd | key=<nowiki>setup-x86_64.exe</nowiki>}} 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)'''<ref>[https://stackoverflow.com/questions/36393757/how-do-i-use-diagnostics-for-perl-on-cygwin cpan - How do I 'use diagnostics' for Perl on Cygwin? - Stack Overflow]</ref><ref>[https://cygwin.com/faq/faq.html#faq.setup.cli Does Setup accept command-line arguments?]</ref>
# Open a command line window
# Navigate to the directory containing {{kbd | key=<nowiki>setup-x86_64.exe</nowiki>}}, for example: {{kbd | key=<nowiki>cd C:\Downloads</nowiki>}}, then press {{kbd | key=<nowiki>Enter</nowiki>}}
# Enter the following command: {{kbd | key=<nowiki>setup-x86_64.exe -q -P "perl_pods"</nowiki>}}

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 {{kbd | key=<nowiki>uname -a</nowiki>}})

== How to resolve: (Cygwin) wget command not found ==
Condition: When I tried to download the MySQLTuner using {{kbd | key=<nowiki>wget</nowiki>}} command but met the error.

Solution: 

# Download the installation file {{kbd | key=<nowiki>setup-x86_64.exe</nowiki>}} of Cygwin from [https://cygwin.com/install.html Cygwin Installation]
# Open the command line window
# Change to the directory where the file {{kbd | key=<nowiki>setup-x86_64.exe</nowiki>}} located e.g. {{kbd | key=<nowiki>cd C:\Downloads></nowiki>}} and than press the key {{kbd | key=<nowiki>Enter</nowiki>}}
# To install the packages: wget. Keyin {{kbd | key=<nowiki>setup-x86_64.exe -q -P "wget"</nowiki>}} or follow the steps on [https://superuser.com/questions/693284/wget-command-not-working-in-cygwin terminal - WGET Command Not Working in Cygwin - Super User] if you prefer the GUI window.

== How to resolve: (Cygwin) unzip: command not found ==
Condition:
<pre>
$ unzip -l sysschema.zip
-bash: unzip: command not found
</pre>

Solution:
# Download the installation file {{kbd | key=<nowiki>setup-x86_64.exe</nowiki>}} of Cygwin from [https://cygwin.com/install.html Cygwin Installation]
# Open the command line window
# Change to the directory where the file {{kbd | key=<nowiki>setup-x86_64.exe</nowiki>}} located e.g. {{kbd | key=<nowiki>cd C:\Downloads></nowiki>}} and than press the key {{kbd | key=<nowiki>Enter</nowiki>}}
# To install the packages: [https://cygwin.com/packages/summary/unzip.html unzip]. Keyin {{kbd | key=<nowiki>setup-x86_64.exe -q -P unzip</nowiki>}}

== How to resolve: Attempted to use login credentials, but they were invalid. ==
Condition:
<pre>
$ perl mysqltuner.pl
 >>  MySQLTuner 1.7.5 - 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: root
Please enter your MySQL administrative password: [!!] Attempted to use login credentials, but they were invalid.
</pre>

Solution:
* Specify the host parameter to command line e.g. {{kbd | key=<nowiki>perl mysqltuner.pl --host 127.0.0.1</nowiki>}}
* Check the typo of mysql account and password

== How to resolve: Performance schema should be activated for better diagnostics ==
Condition:
<pre>
$ perl mysqltuner.pl
-------- Recommendations ---------------------------------------------------------------------------
General recommendations:
    Performance schema should be activated for better diagnostics

</pre>

Solution:
* Verify the MySQL setting. Execute the SQL query {{kbd | key=<nowiki>SHOW VARIABLES LIKE 'performance_schema'</nowiki>}}. The result should be OFF.
* Stop the MySQL service.
* Open the MySQL configuration file named {{kbd | key=<nowiki>my.ini</nowiki>}} on {{Win}} or {{kbd | key=<nowiki>my.cnf</nowiki>}} on {{Linux}} The file maybe located in different path e.g. C:\xampp\mysql\bin\my.ini  on {{Win}}
* Edit the MySQL configuration file

<pre>
[mysqld]
performance_schema = ON
</pre>

* Restart the MySQL service.
* Verify the MySQL setting again. Execute the SQL query {{kbd | key=<nowiki>SHOW VARIABLES LIKE 'performance_schema'</nowiki>}}. The result should be ON.

== References ==
<references/>

{{Template:Troubleshooting}}

[[Category:MySQL]]
[[Category:Data Science]]