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PT-DEADLOCK-LOGGER(1) User Contributed Perl DocumentationPT-DEADLOCK-LOGGER(1)

NAME
       pt-deadlock-logger - Log	MySQL deadlocks.

SYNOPSIS
       Usage: pt-deadlock-logger [OPTIONS] DSN

       pt-deadlock-logger logs information about MySQL deadlocks on the	given
       DSN.  Information is printed to "STDOUT", and it	can also be saved to a
       table by	specifying "--dest".  The tool runs for	forever	unless
       "--run-time" or "--iterations" is specified.

       Print deadlocks on host1:

	  pt-deadlock-logger h=host1

       Print deadlocks on host1	once then exit:

	  pt-deadlock-logger h=host1 --iterations 1

       Save deadlocks on host1 to percona_schema.deadlocks on host2:

	 pt-deadlock-logger h=host1 --dest h=host2,D=percona_schema,t=deadlocks

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:

       o   Read	the tool's documentation

       o   Review the tool's known "BUGS"

       o   Test	the tool on a non-production server

       o   Backup your production server and verify the	backups

DESCRIPTION
       pt-deadlock-logger prints information about MySQL deadlocks by polling
       and parsing "SHOW ENGINE	INNODB STATUS".	 When a	new deadlock occurs,
       it's printed to "STDOUT"	and, if	specified, saved to "--dest".

       Only new	deadlocks are printed.	A fingerprint for each deadlock	is
       created using the deadlock's server, ts,	and thread values (even	if
       these columns are not specified by "--columns").	 A deadlock is printed
       if its fingerprint is different than the	last deadlock's	fingerprint.

       The "--dest" statement uses "INSERT IGNORE" to eliminate	duplicate
       deadlocks, so every deadlock is saved for every "--iterations".

OUTPUT
       New deadlocks are printed to "STDOUT", unless "--quiet" is specified.
       Errors and warnings are printed to "STDERR".

       See also	"--columns" and	"--tab".

INNODB CAVEATS AND DETAILS
       InnoDB's	output is hard to parse	and sometimes there's no way to	do it
       right.

       Sometimes not all information (for example, username or IP address) is
       included	in the deadlock	information.  In this case there's nothing for
       the tool	to put in those	columns.  It may also be the case that the
       deadlock	output is so long (because there were a	lot of locks) that the
       whole thing is truncated.

       Though there are	usually	two transactions involved in a deadlock, there
       are more	locks than that; at a minimum, one more	lock than transactions
       is necessary to create a	cycle in the waits-for graph.  pt-deadlock-
       logger prints the transactions (always two in the InnoDB	output,	even
       when there are more transactions	in the waits-for graph than that) and
       fills in	locks.	It prefers waited-for over held	when choosing lock
       information to output, but you can figure out the rest with a moment's
       thought.	 If you	see one	wait-for and one held lock, you're looking at
       the same	lock, so of course you'd prefer	to see both wait-for locks and
       get more	information.  If the two waited-for locks are not on the same
       table, more than	two transactions were involved in the deadlock.

       Finally,	keep in	mind that, because usernames with spaces are not
       quoted by InnoDB, the tool will generally misreport the second word of
       these usernames as the hostname.

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

       --ask-pass
	   Prompt for a	password when connecting to MySQL.

       --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.

       --clear-deadlocks
	   type: string

	   Use this table to create a small deadlock.  This usually has	the
	   effect of clearing out a huge deadlock, which otherwise consumes
	   the entire output of	"SHOW INNODB STATUS".  The table must not
	   exist.  pt-deadlock-logger will create it with the following
	   structure:

	     CREATE TABLE percona_schema.clear_deadlocks (
	       a INT PRIMARY KEY
	     ) ENGINE=InnoDB

	   After creating the table and	causing	a small	deadlock, the tool
	   will	drop the table again.

       --columns
	   type: Array;	default: server, ts, thread, txn_id, txn_time, user,
	   hostname, ip, db, tbl, idx, lock_type, lock_mode, wait_hold,
	   victim, query

	   The columns are:

	   server
	       The (source) server on which the	deadlock occurred.  This might
	       be useful if you're tracking deadlocks on many servers.

	   ts  The date	and time of the	last detected deadlock.

	   thread
	       The MySQL thread	number,	which is the same as the connection ID
	       in SHOW FULL PROCESSLIST.

	   txn_id
	       The InnoDB transaction ID, which	InnoDB expresses as two
	       unsigned	integers.  I have multiplied them out to be one
	       number.

	   txn_time
	       How long	the transaction	was active when	the deadlock happened.

	   user
	       The connection's	database username.

	   hostname
	       The connection's	host.

	   ip  The connection's	IP address.  If	you specify "--numeric-ip",
	       this is converted to an unsigned	integer.

	   db  The database in which the deadlock occurred.

	   tbl The table on which the deadlock occurred.

	   idx The index on which the deadlock occurred.

	   lock_type
	       The lock	type the transaction held on the lock that caused the
	       deadlock.

	   lock_mode
	       The lock	mode of	the lock that caused the deadlock.

	   wait_hold
	       Whether the transaction was waiting for the lock	or holding the
	       lock.  Usually you will see the two waited-for locks.

	   victim
	       Whether the transaction was selected as the deadlock victim and
	       rolled back.

	   query
	       The query that caused the deadlock.

       --config
	   type: Array

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

       --create-dest-table
	   Create the table specified by "--dest".

	   Normally the	"--dest" table is expected to exist already.  This
	   option causes pt-deadlock-logger to create the table	automatically
	   using the suggested table structure.

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

       --database
	   short form: -D; type: string

	   Connect to this database.

       --defaults-file
	   short form: -F; type: string

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

       --dest
	   type: DSN

	   DSN for where to store deadlocks; specify at	least a	database (D)
	   and table (t).

	   Missing values are filled in	with the same values from the source
	   host, so you	can usually omit most parts of this argument if	you're
	   storing deadlocks on	the same server	on which they happen.

	   The following table structure is suggested if you want to store all
	   the information pt-deadlock-logger can extract about	deadlocks:

	    CREATE TABLE deadlocks (
	      server char(20) NOT NULL,
	      ts timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
	      thread int unsigned NOT NULL,
	      txn_id bigint unsigned NOT NULL,
	      txn_time smallint	unsigned NOT NULL,
	      user char(16) NOT	NULL,
	      hostname char(20)	NOT NULL,
	      ip char(15) NOT NULL, -- alternatively, ip int unsigned NOT NULL
	      db char(64) NOT NULL,
	      tbl char(64) NOT NULL,
	      idx char(64) NOT NULL,
	      lock_type	char(16) NOT NULL,
	      lock_mode	char(1)	NOT NULL,
	      wait_hold	char(1)	NOT NULL,
	      victim tinyint unsigned NOT NULL,
	      query text NOT NULL,
	      PRIMARY KEY  (server,ts,thread)
	    ) ENGINE=InnoDB

	   If you use "--columns", you can omit	whichever columns you don't
	   want	to store.

       --help
	   Show	help and exit.

       --host
	   short form: -h; type: string

	   Connect to host.

       --interval
	   type: time; default:	30

	   How often to	check for deadlocks.  If no "--run-time" is specified,
	   pt-deadlock-logger runs forever, checking for deadlocks at every
	   interval.  See also "--run-time".

       --iterations
	   type: int

	   How many times to check for deadlocks.  By default, this option is
	   undefined which means an infinite number of iterations.  The	tool
	   always exits	for "--run-time", regardless of	the value specified
	   for this option.  For example, the tool will	exit after 1 minute
	   with	"--run-time 1m --iterations 4 --interval 30" because 4
	   iterations at 30 second intervals would take	2 minutes, longer than
	   the 1 mintue	run-time.

       --log
	   type: string

	   Print all output to this file when daemonized.

       --numeric-ip
	   Express IP addresses	as integers.

       --password
	   short form: -p; type: string

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

       --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.

       --port
	   short form: -P; type: int

	   Port	number to use for connection.

       --quiet
	   Do not deadlocks; only print	errors and warnings to "STDERR".

       --run-time
	   type: time

	   How long to run before exiting.  By default pt-deadlock-logger runs
	   forever, checking for deadlocks every "--interval" seconds.

       --set-vars
	   type: Array

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

	   By default, the tool	sets:

	      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.

       --socket
	   short form: -S; type: string

	   Socket file to use for connection.

       --tab
	   Use tabs to separate	columns	instead	of spaces.

       --user
	   short form: -u; type: string

	   User	for login if not current user.

       --version
	   Show	version	and exit.

       --[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 Perconaas 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>.

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.

       o   A

	   dsn:	charset; copy: yes

	   Default character set.

       o   D

	   dsn:	database; copy:	yes

	   Default database.

       o   F

	   dsn:	mysql_read_default_file; copy: yes

	   Only	read default options from the given file

       o   h

	   dsn:	host; copy: yes

	   Connect to host.

       o   p

	   dsn:	password; copy:	yes

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

       o   P

	   dsn:	port; copy: yes

	   Port	number to use for connection.

       o   S

	   dsn:	mysql_socket; copy: yes

	   Socket file to use for connection.

       o   t

	   Table in which to store deadlock information.

       o   u

	   dsn:	user; copy: yes

	   User	for login if not current user.

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:

	  PTDEBUG=1 pt-deadlock-logger ... > FILE 2>&1

       Be careful: debugging output is voluminous and can generate several
       megabytes of 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
       <http://www.percona.com/bugs/pt-deadlock-logger>.

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

       o   Complete command-line used to run the tool

       o   Tool	"--version"

       o   MySQL version of all	servers	involved

       o   Output from the tool	including STDERR

       o   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/>	to download
       the latest release of Percona Toolkit.  Or, get the latest release from
       the command line:

	  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:

	  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/> to learn
       about other free, open-source software from Percona.

COPYRIGHT, LICENSE, AND	WARRANTY
       This program is copyright 2011-2018 Percona LLC and/or its affiliates,
       2007-2011 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
       pt-deadlock-logger 3.2.0

POD ERRORS
       Hey! The	above document had some	coding errors, which are explained
       below:

       Around line 5535:
	   Non-ASCII character seen before =encoding in	'Perconaas'. Assuming
	   UTF-8

perl v5.32.0			  2020-04-23		 PT-DEADLOCK-LOGGER(1)

NAME | SYNOPSIS | RISKS | DESCRIPTION | OUTPUT | INNODB CAVEATS AND DETAILS | OPTIONS | DSN OPTIONS | ENVIRONMENT | SYSTEM REQUIREMENTS | BUGS | DOWNLOADING | AUTHORS | ABOUT PERCONA TOOLKIT | COPYRIGHT, LICENSE, AND WARRANTY | VERSION | POD ERRORS

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