pt-slave-find(1) Find and print replication hierarchy tree of MySQL slaves.


Usage: pt-slave-find [OPTIONS] [DSN]

pt-slave-find finds and prints a hierarchy tree of MySQL slaves.


pt-slave-find --host master-host


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


pt-slave-find connects to a MySQL replication master and finds its slaves. Currently the only thing it can do is print a tree-like view of the replication hierarchy.

The master host can be specified using one of two methods. The first method is to use the standard connection-related command line options: ``--defaults-file'', ``--password'', ``--host'', ``--port'', ``--socket'' or ``--user''.

The second method to specify the master host is a DSN. A DSN is a special syntax that can be either just a hostname (like "" or, or a "key=value,key=value" string. Keys are a single letter:

   === =======
   h   Connect to host
   P   Port number to use for connection
   S   Socket file to use for connection
   u   User for login if not current user
   p   Password to use when connecting
   F   Only read default options from the given file

"pt-slave-find" reads all normal MySQL option files, such as ~/.my.cnf, so you may not need to specify username, password and other common options at all.


An exit status of 0 (sometimes also called a return value or return code) indicates success. Any other value represents the exit status of the Perl process itself.


This tool accepts additional command-line arguments. Refer to the ``SYNOPSIS'' and usage information for details.
Prompt for a password when connecting to MySQL.
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.

type: Array

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

type: string; short form: -D

Database to use.

short form: -F; type: string

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

Show help and exit.
short form: -h; type: string

Connect to host.

short form: -p; type: string

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

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.

short form: -P; type: int

Port number to use for connection.

type: int

Number of levels to recurse in the hierarchy. Default is infinite.

See ``--recursion-method''.

type: array; default: processlist,hosts

Preferred recursion method used to find slaves.

Possible methods are:

  ===========  ==================
  processlist  SHOW PROCESSLIST
  hosts        SHOW SLAVE HOSTS
  none         Do not find slaves

The processlist method is preferred because SHOW SLAVE HOSTS is not reliable. However, the hosts method is required if the server uses a non-standard port (not 3306). Usually pt-slave-find does the right thing and finds the slaves, but you may give a preferred method and it will be used first. If it doesn't find any slaves, the other methods will be tried.

type: string; default: summary

Set what information about the slaves is printed. The report format can be one of the following:

  • hostname

    Print just the hostname name of the slaves. It looks like:
  • summary

    Print a summary of each slave's settings. This report shows more information about each slave, like:
      Version         5.1.34-log
      Server ID       12345
      Uptime          04:56 (started 2010-06-17T11:21:22)
      Replication     Is not a slave, has 1 slaves connected
      Binary logging  STATEMENT
      Slave status    
      Slave mode      STRICT
      Auto-increment  increment 1, offset 1
         Version         5.1.34-log
         Server ID       12346
         Uptime          04:54 (started 2010-06-17T11:21:24)
         Replication     Is a slave, has 1 slaves connected
         Binary logging  STATEMENT
         Slave status    0 seconds behind, running, no errors
         Slave mode      STRICT
         Auto-increment  increment 1, offset 1
Resolve ip-address to hostname. Report will print both IP and hostname.

Example: (

Might delay runtime a few seconds.

type: Array

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

By default, the tool sets:


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.

short form: -S; type: string

Socket file to use for connection.

short form: -u; type: string

User for login if not current user.

Show version and exit.


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.


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-slave-find ... > FILE 2>&1

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


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


For a list of known bugs, see <>.

Please report bugs at <>. Include the following information in your bug report:

  • Complete command-line used to run the tool
  • Tool ``--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''.


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


You can also get individual tools from the latest release:


Replace "TOOL" with the name of any tool.


Baron Schwartz and Daniel Nichter


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


This program is copyright 2011-2016 Percona LLC and/or its affiliates, 2007-2011 Baron Schwartz.


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.


pt-slave-find 2.2.17