.. program:: pt-kill

==================
:program:`pt-kill`
==================

NAME
====

:program:`pt-kill` - Kill MySQL queries that match certain criteria.

SYNOPSIS
========

Usage
-----

::

  pt-kill [OPTIONS] [DSN]

:program:`pt-kill` kills MySQL connections.  :program:`pt-kill` connects to MySQL and gets queries
from SHOW PROCESSLIST if no FILE is given.  Else, it reads queries from one
or more FILE which contains the output of SHOW PROCESSLIST.  If FILE is -,
:program:`pt-kill` reads from STDIN.

Kill queries running longer than 60s:

.. code-block:: bash

   pt-kill --busy-time 60 --kill

Print, do not kill, queries running longer than 60s:

.. code-block:: bash

   pt-kill --busy-time 60 --print

Check for sleeping processes and kill them all every 10s:

.. code-block:: bash

   pt-kill --match-command Sleep --kill --victims all --interval 10

Print all login processes:

.. code-block:: bash

   pt-kill --match-state login --print --victims all

See which queries in the processlist right now would match:

.. code-block:: bash

    mysql -e "SHOW PROCESSLIST" > proclist.txt
    pt-kill --test-matching proclist.txt --busy-time 60 --print

RISKS
=====

Percona Toolkit is mature, proven in the real world, and well tested,
but all database tools can pose a risk to the system and the database
server.  Before using this tool, please:

* Read the tool's documentation

* Review the tool's known "BUGS"

* Test the tool on a non-production server

* Backup your production server and verify the backups

DESCRIPTION
===========

:program:`pt-kill` captures queries from SHOW PROCESSLIST, filters them, and then either
kills or prints them.  This is also known as a "slow query sniper" in some
circles.  The idea is to watch for queries that might be consuming too many
resources, and kill them.

For brevity, we talk about killing queries, but they may just be printed
(or some other future action) depending on what options are given.

Normally :program:`pt-kill` connects to MySQL to get queries from SHOW PROCESSLIST.
Alternatively, it can read SHOW PROCESSLIST output from files.  In this case,
:program:`pt-kill` does not connect to MySQL and :option:`--kill` has no effect.  You should
use :option:`--print` instead when reading files.  The ability to read a file
with :option:`--test-matching` allows you to capture SHOW PROCESSLIST and test it
later with :program:`pt-kill` to make sure that your matches kill the proper queries.
There are a lot of special rules to follow, such as "don't kill replication
threads," so be careful not to kill something important!

Two important options to know are :option:`--busy-time` and :option:`--victims`.
First, whereas most match/filter options match their corresponding value from
SHOW PROCESSLIST (e.g. :option:`--match-command` matches a query's Command value),
the Time value is matched by :option:`--busy-time`.  See also :option:`--interval`.

Second, :option:`--victims` controls which matching queries from each class are
killed.  By default, the matching query with the highest Time value is killed
(the oldest query).  See the next section, "GROUP, MATCH AND KILL",
for more details.

Usually you need to specify at least one ``--match`` option, else no
queries will match.  Or, you can specify :option:`--match-all` to match all queries
that aren't ignored by an ``--ignore`` option.

GROUP, MATCH AND KILL
=====================

Queries pass through several steps to determine which exactly will be killed
(or printed--whatever action is specified).  Understanding these steps will
help you match precisely the queries you want.

The first step is grouping queries into classes.  The :option:`--group-by` option
controls grouping.  By default, this option has no value so all queries are
grouped into one default class.  All types of matching and filtering
(the next step) are applied per-class.  Therefore, you may need to group
queries in order to match/filter some classes but not others.

The second step is matching.  Matching implies filtering since if a query
doesn't match some criteria, it is removed from its class.
Matching happens for each class.  First, queries are filtered from their
class by the various ``Query Matches`` options like :option:`--match-user`.
Then, entire classes are filtered by the various ``Class Matches`` options
like :option:`--query-count`.

The third step is victim selection, that is, which matching queries in each
class to kill.  This is controlled by the :option:`--victims` option.  Although
many queries in a class may match, you may only want to kill the oldest
query, or all queries, etc.

The forth and final step is to take some action on all matching queries
from all classes.  The ``Actions`` options specify which actions will be
taken.  At this step, there are no more classes, just a single list of
queries to kill, print, etc.

:program:`pt-kill` will kill all the queries matching ANY of the specified criteria (logical OR).
For example, using:

.. code-block:: bash

   --busy-time 114 --match-command 'Query|Execute'

will kill all queries having busy-time > 114 ``OR`` where the command is ``Query`` or ``Execute``

If you want to kill only the queries where ``busy-time `` 114> ``AND`` the command is Query or
Execute, you need to use "--kill-busy-commands:

.. code-block:: bash

   --busy-time 114 --kill-busy-commands 'Query|Execute'

OUTPUT
======

If only :option:`--kill` is given, then there is no output.  If only
:option:`--print` is given, then a timestamped KILL statement if printed
for every query that would have been killed, like:

.. code-block:: bash

   # 2009-07-15T15:04:01 KILL 8 (Query 42 sec) SELECT * FROM huge_table

The line shows a timestamp, the query's Id (8), its Time (42 sec) and its
Info (usually the query SQL).

If both :option:`--kill` and :option:`--print` are given, then matching queries are
killed and a line for each like the one above is printed.

Any command executed by :option:`--execute-command` is responsible for its own
output and logging.  After being executed, :program:`pt-kill` has no control or interaction
with the command.

OPTIONS
=======

Specify at least one of :option:`--kill`, :option:`--kill-query`, :option:`--print`, :option:`--execute-command` or :option:`--stop`.

:option:`--any-busy-time` and :option:`--each-busy-time` are mutually exclusive.

:option:`--kill` and :option:`--kill-query` are mutually exclusive.

:option:`--daemonize` and :option:`--test-matching` are mutually exclusive.

This tool accepts additional command-line arguments.  Refer to the
"SYNOPSIS" and usage information for details.

.. option:: --ask-pass

 Prompt for a password when connecting to MySQL.

.. option:: --charset

 short form: -A; type: string

 Default character set.  If the value is utf8, sets Perl's binmode on
 STDOUT to utf8, passes the mysql_enable_utf8 option to DBD::mysql, and runs SET
 NAMES UTF8 after connecting to MySQL.  Any other value sets binmode on STDOUT
 without the utf8 layer, and runs SET NAMES after connecting to MySQL.

.. option:: --config

 type: Array

 Read this comma-separated list of config files; if specified, this must be the
 first option on the command line.

.. option:: --create-log-table

 Create the :option:`--log-dsn` table if it does not exist.

 This option causes the table specified by :option:`--log-dsn` to be created with the
 default structure shown in the documentation for that option.

.. option:: --daemonize

 Fork to the background and detach from the shell.  POSIX operating systems
 only.

.. option:: --database

 short form: -D; type: string

 The database to use for the connection.

.. option:: --defaults-file

 short form: -F; type: string

 Only read mysql options from the given file.  You must give an absolute
 pathname.

.. option:: --filter

 type: string

 Discard events for which this Perl code doesn't return true.

 This option is a string of Perl code or a file containing Perl code that gets
 compiled into a subroutine with one argument: $event.  This is a hashref.
 If the given value is a readable file, then :program:`pt-kill` reads the entire
 file and uses its contents as the code.  The file should not contain
 a shebang (#!/usr/bin/perl) line.

 If the code returns true, the chain of callbacks continues; otherwise it ends.
 The code is the last statement in the subroutine other than ``return $event``.
 The subroutine template is:

 .. code-block:: bash

    sub { $event = shift; filter && return $event; }

 Filters given on the command line are wrapped inside parentheses like like
 ``( filter )``.  For complex, multi-line filters, you must put the code inside
 a file so it will not be wrapped inside parentheses.  Either way, the filter
 must produce syntactically valid code given the template.  For example, an
 if-else branch given on the command line would not be valid:

 .. code-block:: bash

    --filter 'if () { } else { }'  # WRONG

 Since it's given on the command line, the if-else branch would be wrapped inside
 parentheses which is not syntactically valid.  So to accomplish something more
 complex like this would require putting the code in a file, for example
 filter.txt:

 .. code-block:: bash

    my $event_ok; if (...) { $event_ok=1; } else { $event_ok=0; } $event_ok

 Then specify ``--filter filter.txt`` to read the code from filter.txt.

 If the filter code won't compile, :program:`pt-kill` will die with an error.
 If the filter code does compile, an error may still occur at runtime if the
 code tries to do something wrong (like pattern match an undefined value).
 :program:`pt-kill` does not provide any safeguards so code carefully!

 It is permissible for the code to have side effects (to alter ``$event``).

.. option:: --group-by

 type: string

 Apply matches to each class of queries grouped by this SHOW PROCESSLIST column.
 In addition to the basic columns of SHOW PROCESSLIST (user, host, command,
 state, etc.), queries can be matched by ``fingerprint`` which abstracts the
 SQL query in the ``Info`` column.

 By default, queries are not grouped, so matches and actions apply to all
 queries.  Grouping allows matches and actions to apply to classes of
 similar queries, if any queries in the class match.

 For example, detecting cache stampedes (see ``all-but-oldest`` under
 :option:`--victims` for an explanation of that term) requires that queries are
 grouped by the ``arg`` attribute.  This creates classes of identical queries
 (stripped of comments).  So queries ``"SELECT c FROM t WHERE id=1"`` and
 ``"SELECT c FROM t WHERE id=1"`` are grouped into the same class, but
 query c<"SELECT c FROM t WHERE id=3"> is not identical to the first two
 queries so it is grouped into another class. Then when :option:`--victims`
 ``all-but-oldest`` is specified, all but the oldest query in each class is
 killed for each class of queries that matches the match criteria.

.. option:: --help

 Show help and exit.

.. option:: --host

 short form: -h; type: string; default: localhost

 Connect to host.

.. option:: --interval

 type: time

 How often to check for queries to kill.  If :option:`--busy-time` is not given,
 then the default interval is 30 seconds.  Else the default is half as often
 as :option:`--busy-time`.  If both :option:`--interval` and :option:`--busy-time` are given,
 then the explicit :option:`--interval` value is used.

 See also :option:`--run-time`.

.. option:: --log

 type: string

 Print all output to this file when daemonized.

.. option:: --log-dsn

 type: DSN

 Store each query killed in this DSN.

 The argument specifies a table to store all killed queries.  The DSN
 passed in must have the database (D) and table (t) options. The
 table must have at least the following columns.  You can add more columns for
 your own special purposes, but they won't be used by :program:`pt-kill`.  The
 following CREATE TABLE definition is also used for :option:`--create-log-table`.
 MAGIC_create_log_table:

 .. code-block:: sql

     CREATE TABLE kill_log (
        kill_id     int(10) unsigned NOT NULL AUTO_INCREMENT,
        server_id   bigint(4) NOT NULL DEFAULT '0',
        timestamp   DATETIME,
        reason      TEXT,
        kill_error  TEXT,
        Id          bigint(4) NOT NULL DEFAULT '0',
        User        varchar(16) NOT NULL DEFAULT '',
        Host        varchar(64) NOT NULL DEFAULT '',
        db          varchar(64) DEFAULT NULL,
        Command     varchar(16) NOT NULL DEFAULT '',
        Time        int(7) NOT NULL DEFAULT '0',
        State       varchar(64) DEFAULT NULL,
        Info        longtext,
        Time_ms     bigint(21) DEFAULT '0', # NOTE, TODO: currently not used
        PRIMARY KEY (kill_id)
     ) DEFAULT CHARSET=utf8


.. option:: --json

 Prints killed queries as JSON, must be used with :option:`--print`. For example:

 .. code-block:: bash

     --print --json

 The usual plain-text output from :option:`--print` will not be displayed.

 JSON output will be in the format of:

 .. code-block:: bash

     {
        "Command": "Query",
        "Host": "10.0.0.1:9999",
        "Id": 1234,
        "Info": "SELECT SLEEP(5)",
        "State": "User sleep",
        "Time": 10,
        "User": "my_user",
        "Db": "my_db",
        "Kill_Error": "",
        "Digest": "58A43A7DA83F58C1",
        "Reason": "Exceeds busy time\nQuery matches Command spec",
        "Timestamp": "2022-01-01T00:00:00"
     }


.. option:: --json-fields

 type: string

 Specify a list of additional key:value pairs to include in JSON output when
 using :option:`--json`, the value of this parameter must be specified in the
 format of:

 .. code-block:: bash

     --json-fields key1:value1,key2:value2

 Any fields specified using :option:`--json-fields` will be included in the
 :option:`--json` output.

 For example:

 .. code-block:: bash

     --print --json --json-fields hostname:$(hostname),tag:my_tag

 Will result in JSON records being written to "kill_log.json" using this format:

 .. code-block:: bash

     {
        "Command": "Query",
        "Host": "10.0.0.1:9999",
        "Id": 1234,
        "Info": "SELECT SLEEP(5)",
        "State": "User sleep",
        "Time": 10,
        "User": "my_user",
        "Db": "my_db",
        "Kill_Error": "",
        "Digest": "58A43A7DA83F58C1",
        "Reason": "Exceeds busy time\nQuery matches Command spec",
        "Timestamp": "2022-01-01T00:00:00",
        "hostname": "my_host",
        "tag": "my_tag"
     }


.. option:: --password

 short form: -p; type: string

 Password to use when connecting.
 If password contains commas they must be escaped with a backslash: "exam\,ple"

.. option:: --pid

 type: string

 Create the given PID file.  The tool won't start if the PID file already
 exists and the PID it contains is different than the current PID.  However,
 if the PID file exists and the PID it contains is no longer running, the
 tool will overwrite the PID file with the current PID.  The PID file is
 removed automatically when the tool exits.

.. option:: --port

 short form: -P; type: int

 Port number to use for connection.

.. option:: --query-id

 Prints an ID of the query that was just killed. This is
 equivalent to the "ID" output of pt-query-digest. This allows
 cross-referencing the output of both tools.

 Example:

 .. code-block:: bash

     Query ID 0xE9800998ECF8427E

 Note that this is a digest (or hash) of the query's "fingerprint",
 so queries of the same form but with different values will have the same ID.
 See pt-query-digest for more information.

.. option:: --rds

 Denotes the instance in question is on Amazon RDS. By default :program:`pt-kill` runs
 the MySQL command "kill" for :option:`--kill` and "kill query" :option:`--kill-query`.
 On RDS these two commands are not available and are replaced by function calls.
 This option modifies :option:`--kill` to use "CALL mysql.rds_kill(thread-id)" instead
 and :option:`--kill-query` to use "CALL mysql.rds_kill_query(thread-id)"

.. option:: --run-time

 type: time

 How long to run before exiting.  By default :program:`pt-kill` runs forever, or until
 its process is killed or stopped by the creation of a :option:`--sentinel` file.
 If this option is specified, :program:`pt-kill` runs for the specified amount of time
 and sleeps :option:`--interval` seconds between each check of the PROCESSLIST.

.. option:: --sentinel

 type: string; default: /tmp/pt-kill-sentinel

 Exit if this file exists.

 The presence of the file specified by :option:`--sentinel` will cause all
 running instances of :program:`pt-kill` to exit.  You might find this handy to stop cron
 jobs gracefully if necessary.  See also :option:`--stop`.

.. option:: --slave-user

 type: string

 Sets the user to be used to connect to the slaves.
 This parameter allows you to have a different user with less privileges on the
 slaves but that user must exist on all slaves.

.. option:: --slave-password

 type: string

 Sets the password to be used to connect to the slaves.
 It can be used with --slave-user and the password for the user must be the same
 on all slaves.

.. option:: --set-vars

 type: Array

 Set the MySQL variables in this comma-separated list of ``variable=value`` pairs.

 By default, the tool sets:

 .. code-block:: bash

     wait_timeout=10000

 Variables specified on the command line override these defaults.  For
 example, specifying ``--set-vars wait_timeout=500`` overrides the defaultvalue of ``10000``.

 The tool prints a warning and continues if a variable cannot be set.

.. option:: --socket

 short form: -S; type: string

 Socket file to use for connection.

.. option:: --stop

 Stop running instances by creating the :option:`--sentinel` file.

 Causes :program:`pt-kill` to create the sentinel file specified by :option:`--sentinel` and
 exit.  This should have the effect of stopping all running instances which are
 watching the same sentinel file.

.. option:: --[no]strip-comments

 default: yes

 Remove SQL comments from queries in the Info column of the PROCESSLIST.

.. option:: --user

 short form: -u; type: string

 User for login if not current user.

.. option:: --version

 Show version and exit.

.. option:: --[no]version-check

 default: yes

 Check for the latest version of Percona Toolkit, MySQL, and other programs.

 This is a standard "check for updates automatically" feature, with two
 additional features.  First, the tool checks its own version and also the
 versions of the following software: operating system, Percona Monitoring and
 Management (PMM), MySQL, Perl, MySQL driver for Perl (DBD::mysql), and
 Percona Toolkit. Second, it checks for and warns about versions with known
 problems. For example, MySQL 5.5.25 had a critical bug and was re-released
 as 5.5.25a.

 A secure connection to Percona’s Version Check database server is done to
 perform these checks. Each request is logged by the server, including software
 version numbers and unique ID of the checked system. The ID is generated by the
 Percona Toolkit installation script or when the Version Check database call is
 done for the first time.

 Any updates or known problems are printed to STDOUT before the tool's normal
 output.  This feature should never interfere with the normal operation of the
 tool.

 For more information, visit `https://www.percona.com/doc/percona-toolkit/LATEST/version-check.html <https://www.percona.com/doc/percona-toolkit/LATEST/version-check.html>`_.

.. option:: --victims

 type: string; default: oldest

 Which of the matching queries in each class will be killed.  After classes
 have been matched/filtered, this option specifies which of the matching
 queries in each class will be killed (or printed, etc.).  The following
 values are possible:

 oldest

  Only kill the single oldest query.  This is to prevent killing queries that
  aren't really long-running, they're just long-waiting.  This sorts matching
  queries by Time and kills the one with the highest Time value.


 all

  Kill all queries in the class.


 all-but-oldest

  Kill all but the oldest query.  This is the inverse of the ``oldest`` value.

  This value can be used to prevent "cache stampedes", the condition where
  several identical queries are executed and create a backlog while the first
  query attempts to finish.  Since all queries are identical, all but the first
  query are killed so that it can complete and populate the cache.


.. option:: --wait-after-kill

 type: time

 Wait after killing a query, before looking for more to kill.  The purpose of
 this is to give blocked queries a chance to execute, so we don't kill a query
 that's blocking a bunch of others, and then kill the others immediately
 afterwards.

.. option:: --wait-before-kill

 type: time

 Wait before killing a query.  The purpose of this is to give
 :option:`--execute-command` a chance to see the matching query and gather other
 MySQL or system information before it's killed.

QUERY MATCHES
=============

These options filter queries from their classes.  If a query does not
match, it is removed from its class.  The ``--ignore`` options take precedence.
The matches for command, db, host, etc. correspond to the columns returned
by SHOW PROCESSLIST: Command, db, Host, etc.  All pattern matches are
case-sensitive by default, but they can be made case-insensitive by specifying
a regex pattern like ``(?i-xsm:select)``.

See also "GROUP, MATCH AND KILL".

.. option:: --busy-time

 type: time; group: Query Matches

 Match queries that have been running for longer than this time.  The queries
 must be in Command=Query status.  This matches a query's Time value as
 reported by SHOW PROCESSLIST.

.. option:: --idle-time

 type: time; group: Query Matches

 Match queries that have been idle/sleeping for longer than this time.
 The queries must be in Command=Sleep status.  This matches a query's Time
 value as reported by SHOW PROCESSLIST.

.. option:: --ignore-command

 type: string; group: Query Matches

 Ignore queries whose Command matches this Perl regex.

 See :option:`--match-command`.

.. option:: --ignore-db

 type: string; group: Query Matches

 Ignore queries whose db (database) matches this Perl regex.

 See :option:`--match-db`.

.. option:: --ignore-host

 type: string; group: Query Matches

 Ignore queries whose Host matches this Perl regex.

 See :option:`--match-host`.

.. option:: --ignore-info

 type: string; group: Query Matches

 Ignore queries whose Info (query) matches this Perl regex.

 See :option:`--match-info`.

.. option:: --[no]ignore-self

 default: yes; group: Query Matches

 Don't kill :program:`pt-kill`'s own connection.

.. option:: --ignore-state

 type: string; group: Query Matches; default: Locked

 Ignore queries whose State matches this Perl regex.  The default is to keep
 threads from being killed if they are locked waiting for another thread.

 See :option:`--match-state`.

.. option:: --ignore-user

 type: string; group: Query Matches

 Ignore queries whose user matches this Perl regex.

 See :option:`--match-user`.

.. option:: --match-all

 group: Query Matches

 Match all queries that are not ignored.  If no ignore options are specified,
 then every query matches (except replication threads, unless
 :option:`--replication-threads` is also specified).  This option allows you to
 specify negative matches, i.e. "match every query *except*..." where the
 exceptions are defined by specifying various ``--ignore`` options.

 This option is *not* the same as :option:`--victims` ``all``.  This option matches
 all queries within a class, whereas :option:`--victims` ``all`` specifies that all
 matching queries in a class (however they matched) will be killed.  Normally,
 however, the two are used together because if, for example, you specify
 :option:`--victims` ``oldest``, then although all queries may match, only the oldest
 will be killed.

.. option:: --match-command

 type: string; group: Query Matches

 Match only queries whose Command matches this Perl regex.

 Common Command values are:

 .. code-block:: bash

    Query
    Sleep
    Binlog Dump
    Connect
    Delayed insert
    Execute
    Fetch
    Init DB
    Kill
    Prepare
    Processlist
    Quit
    Reset stmt
    Table Dump

 See `http://dev.mysql.com/doc/refman/5.1/en/thread-commands.html <http://dev.mysql.com/doc/refman/5.1/en/thread-commands.html>`_ for a full
 list and description of Command values.

.. option:: --match-db

 type: string; group: Query Matches

 Match only queries whose db (database) matches this Perl regex.

.. option:: --match-host

 type: string; group: Query Matches

 Match only queries whose Host matches this Perl regex.

 The Host value often time includes the port like "host:port".

.. option:: --match-info

 type: string; group: Query Matches

 Match only queries whose Info (query) matches this Perl regex.

 The Info column of the processlist shows the query that is being executed
 or NULL if no query is being executed.

.. option:: --match-state

 type: string; group: Query Matches

 Match only queries whose State matches this Perl regex.

 Common State values are:

 .. code-block:: bash

    Locked
    login
    copy to tmp table
    Copying to tmp table
    Copying to tmp table on disk
    Creating tmp table
    executing
    Reading from net
    Sending data
    Sorting for order
    Sorting result
    Table lock
    Updating

 See `http://dev.mysql.com/doc/refman/5.1/en/general-thread-states.html <http://dev.mysql.com/doc/refman/5.1/en/general-thread-states.html>`_ for
 a full list and description of State values.

.. option:: --match-user

 type: string; group: Query Matches

 Match only queries whose User matches this Perl regex.

.. option:: --replication-threads

 group: Query Matches

 Allow matching and killing replication threads.

 By default, matches do not apply to replication threads; i.e. replication
 threads are completely ignored.  Specifying this option allows matches to
 match (and potentially kill) replication threads on masters and slaves.

.. option:: --test-matching

 type: array; group: Query Matches

 Files with processlist snapshots to test matching options against.  Since
 the matching options can be complex, you can save snapshots of processlist
 in files, then test matching options against queries in those files.

 This option disables :option:`--run-time`, :option:`--interval`,
 and :option:`--[no]ignore-self`.

CLASS MATCHES
=============

These matches apply to entire query classes.  Classes are created by specifying
the :option:`--group-by` option, else all queries are members of a single, default
class.

See also "GROUP, MATCH AND KILL".

.. option:: --any-busy-time

 type: time; group: Class Matches

 Match query class if any query has been running for longer than this time.
 "Longer than" means that if you specify ``10``, for example, the class will
 only match if there's at least one query that has been running for greater
 than 10 seconds.

 See :option:`--each-busy-time` for more details.

.. option:: --each-busy-time

 type: time; group: Class Matches

 Match query class if each query has been running for longer than this time.
 "Longer than" means that if you specify ``10``, for example, the class will
 only match if each and every query has been running for greater than 10
 seconds.

 See also :option:`--any-busy-time` (to match a class if ANY query has been running
 longer than the specified time) and :option:`--busy-time`.

.. option:: --query-count

 type: int; group: Class Matches

 Match query class if it has at least this many queries.  When queries are
 grouped into classes by specifying :option:`--group-by`, this option causes matches
 to apply only to classes with at least this many queries.  If :option:`--group-by`
 is not specified then this option causes matches to apply only if there
 are at least this many queries in the entire SHOW PROCESSLIST.

.. option:: --verbose

 short form: -v

 Print information to STDOUT about what is being done.

ACTIONS
=======

These actions are taken for every matching query from all classes.
The actions are taken in this order: :option:`--print`, :option:`--execute-command`,
:option:`--kill` / :option:`--kill-query`.  This order allows :option:`--execute-command`
to see the output of :option:`--print` and the query before
:option:`--kill` / :option:`--kill-query`.  This may be helpful because :program:`pt-kill` does
not pass any information to :option:`--execute-command`.

See also "GROUP, MATCH AND KILL".

.. option:: --execute-command

 type: string; group: Actions

 Execute this command when a query matches.

 After the command is executed, :program:`pt-kill` has no control over it, so the command
 is responsible for its own info gathering, logging, interval, etc.  The
 command is executed each time a query matches, so be careful that the command
 behaves well when multiple instances are ran.  No information from :program:`pt-kill` is
 passed to the command.

 See also :option:`--wait-before-kill`.

.. option:: --kill

 group: Actions

 Kill the connection for matching queries.

 This option makes :program:`pt-kill` kill the connections (a.k.a. processes, threads) that
 have matching queries.  Use :option:`--kill-query` if you only want to kill
 individual queries and not their connections.

 Unless :option:`--print` is also given, no other information is printed that shows
 that :program:`pt-kill` matched and killed a query.

 See also :option:`--wait-before-kill` and :option:`--wait-after-kill`.

.. option:: --kill-busy-commands

 type: string; default: Query

 group: Actions

 Comma sepatated list of commands that will be watched/killed if they ran for
 more than :option:`--busy-time` seconds. Default: ``Query``

 By default, :option:`--busy-time` kills only ``Query`` commands but in some cases, it
 is needed to make :option:`--busy-time` to watch and kill other commands. For example,
 a prepared statement execution command is ``Execute`` instead of ``Query``. In this
 case, specifying ``--kill-busy-commands=Query,Execute`` will also kill the prepared
 stamente execution.

.. option:: --kill-query

 group: Actions

 Kill matching queries.

 This option makes :program:`pt-kill` kill matching queries.  This requires MySQL 5.0 or
 newer.  Unlike :option:`--kill` which kills the connection for matching queries,
 this option only kills the query, not its connection.

.. option:: --print

 group: Actions

 Print a KILL statement for matching queries; does not actually kill queries.

 If you just want to see which queries match and would be killed without
 actually killing them, specify :option:`--print`.  To both kill and print
 matching queries, specify both :option:`--kill` and :option:`--print`.

.. option:: --fingerprint

 group: Actions

 Modifies the :option:`--print` behaviour and forces the query fingerprint to be
 displayed instead of an original query.

DSN OPTIONS
===========

These DSN options are used to create a DSN.  Each option is given like
``option=value``.  The options are case-sensitive, so P and p are not the
same option.  There cannot be whitespace before or after the ``=`` and
if the value contains whitespace it must be quoted.  DSN options are
comma-separated.  See the percona-toolkit manpage for full details.

* A

 dsn: charset; copy: yes

 Default character set.

* D

 dsn: database; copy: yes

 Default database.

* F

 dsn: mysql_read_default_file; copy: yes

 Only read default options from the given file

* h

 dsn: host; copy: yes

 Connect to host.

* p

 dsn: password; copy: yes

 Password to use when connecting.
 If password contains commas they must be escaped with a backslash: "exam\,ple"

* P

 dsn: port; copy: yes

 Port number to use for connection.

* S

 dsn: mysql_socket; copy: yes

 Socket file to use for connection.

* u

 dsn: user; copy: yes

 User for login if not current user.

* t

 Table to log actions in, if passed through --log-dsn.

ENVIRONMENT
===========

The environment variable ``PTDEBUG`` enables verbose debugging output to STDERR.
To enable debugging and capture all output to a file, run the tool like:

.. code-block:: bash

    PTDEBUG=1 pt-kill ... > FILE 2>&1

Be careful: debugging output is voluminous and can generate several megabytes
of output.

ATTENTION
=========

Using <PTDEBUG> might expose passwords. When debug is enabled, all command line
parameters are shown in the output.

SYSTEM REQUIREMENTS
===================

You need Perl, DBI, DBD::mysql, and some core packages that ought to be
installed in any reasonably new version of Perl.

BUGS
====

For a list of known bugs, see `https://jira.percona.com/projects/PT/issues <https://jira.percona.com/projects/PT/issues>`_.

Please report bugs at `https://jira.percona.com/projects/PT <https://jira.percona.com/projects/PT>`_.
Include the following information in your bug report:

* Complete command-line used to run the tool

* Tool :option:`--version`

* MySQL version of all servers involved

* Output from the tool including STDERR

* Input files (log/dump/config files, etc.)

If possible, include debugging output by running the tool with ``PTDEBUG``;
see "ENVIRONMENT".

DOWNLOADING
===========

Visit `http://www.percona.com/software/percona-toolkit/ <http://www.percona.com/software/percona-toolkit/>`_ to download the
latest release of Percona Toolkit.  Or, get the latest release from the
command line:

.. code-block:: bash

    wget percona.com/get/percona-toolkit.tar.gz

    wget percona.com/get/percona-toolkit.rpm

    wget percona.com/get/percona-toolkit.deb

You can also get individual tools from the latest release:

.. code-block:: bash

    wget percona.com/get/TOOL

Replace ``TOOL`` with the name of any tool.

AUTHORS
=======

Baron Schwartz and Daniel Nichter

ABOUT PERCONA TOOLKIT
=====================

This tool is part of Percona Toolkit, a collection of advanced command-line
tools for MySQL developed by Percona.  Percona Toolkit was forked from two
projects in June, 2011: Maatkit and Aspersa.  Those projects were created by
Baron Schwartz and primarily developed by him and Daniel Nichter.  Visit
`http://www.percona.com/software/ <http://www.percona.com/software/>`_ to learn about other free, open-source
software from Percona.

COPYRIGHT, LICENSE, AND WARRANTY
================================

This program is copyright 2011-2021 Percona LLC and/or its affiliates,
2009-2011 Baron Schwartz.

THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, version 2; OR the Perl Artistic License.  On UNIX and similar
systems, you can issue \`man perlgpl' or \`man perlartistic' to read these
licenses.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA  02111-1307  USA.

VERSION
=======

:program:`pt-kill` 3.5.7