Update pt-kill Added new features that can support tidb

[suyestyle]

• The contributed code is licensed under GPL v2.0
• Contributor Licence Agreement (CLA) is signed
• util/update-modules has been ran
• Documentation updated
• Test suite update

[it-percona-cla]

All committers have signed the CLA.

[svetasmirnova]

Please add a test case and make "mysql" default value for the "db-type" parameter. You can find an example of how to do it in the definition of option recursion-method for pt-online-schema-change utility.

[suyestyle]

If you want to add rules to mysql clusters, you can do so

pt-kill --log-dsn D=3306_kill_log,t=99755_r_3306_killsql_log,h=192.168.1.1,P=3307,u=dba,p=password --host=192.168.1.2 --port=3306 --user=dba --password=password --create-log-table --no-version-check  --busy-time=4s --match-command=Query --match-info='SELECT|select|Select' --ignore-user=inception --victim all --interval 1 --kill --db-type=mysql --daemonize

Or do this

pt-kill --log-dsn D=3306_kill_log,t=99755_r_3306_killsql_log,h=192.168.1.1,P=3307,u=dba,p=password --host=192.168.1.2 --port=3306 --user=dba --password=password --create-log-table --no-version-check  --busy-time=4s --match-command=Query --match-info='SELECT|select|Select' --ignore-user=inception --victim all --interval 1 --kill --daemonize

If you want to add rules to tidb clusters, you can do so

pt-kill --log-dsn D=3306_kill_log,t=99755_r_3306_killsql_log,h=192.168.1.1,P=3307,u=dba,p=password --host=192.168.1.2 --port=4001 --user=dba --password=password --create-log-table --no-version-check  --busy-time=4s --match-command=Query --match-info='SELECT|select|Select' --ignore-user=inception --victim all --interval 1 --kill --db-type=tidb --daemonize

[svetasmirnova]

Please resolve my comments and add a test case. You will find examples in t/pt-kill.

[svetasmirnova]

This is auto-generated code. No change should be here.

I also do not understand why you need to explicitly import DBI for the code you propose.

[svetasmirnova]

Here should be the default value for mysql. Please check other options where the default value is defined.

[suyestyle]

How do I provide the use cases you're talking about.

[svetasmirnova]

@suyestyle Please check CONTRIBUTING.md and files in t/pt-kill.

[suyestyle]

Thank you for your patience.

I have put my use case in the above answer, is there any problem with this way?

I can't find any use case information here on t/pt-kill, a lot of it is code information.

[svetasmirnova]

@suyestyle I am not asking about the use case. I am asking about regression tests (https://en.wikipedia.org/wiki/Regression_testing) that we run before releasing the new version of Percona Toolkit to ensure that no previously added feature is broken. You will find examples of such tests in the t/pt-kill directory. There is also information at https://github.com/percona/percona-toolkit/blob/3.x/CONTRIBUTING.md#setting-up-the-development-environment-and-testing

[suyestyle]

The first contact with open source project is not familiar with the operation process, it seems to me a little complicated, then ignore this PR, thank you.