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mk-slave-find.1p - Man Page

Find and print replication hierarchy tree of MySQL slaves.


Usage: mk-slave-find [OPTION...] MASTER-HOST

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


   mk-slave-find --host master-host


The following section is included to inform users about the potential risks, whether known or unknown, of using this tool.  The two main categories of risks are those created by the nature of the tool (e.g. read-only tools vs. read-write tools) and those created by bugs.

mk-slave-find is read-only and very low-risk.

At the time of this release, we know of no bugs that could cause serious harm to users.

The authoritative source for updated information is always the online issue tracking system.  Issues that affect this tool will be marked as such.  You can see a list of such issues at the following URL: <http://www.maatkit.org/bugs/mk-slave-find>.

See also "Bugs" for more information on filing bugs and getting help.


mk-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 server.domain.com 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

mk-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.

Exit Status

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.


type: string

Create the given PID file.  The file contains the process ID of the script. The PID file is removed when the script exits.  Before starting, the script checks if the PID file already exists.  If it does not, then the script creates and writes its own PID to it.  If it does, then the script checks the following: if the file contains a PID and a process is running with that PID, then the script dies; or, if there is no process running with that PID, then the script overwrites the file with its own PID and starts; else, if the file contains no PID, then the script dies.


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: string

Preferred recursion method used to find slaves.

Possible methods are:

  ===========  ================
  processlist  SHOW PROCESSLIST
  hosts        SHOW SLAVE HOSTS

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 mk-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

type: string; default: wait_timeout=10000

Set these MySQL variables.  Immediately after connecting to MySQL, this string will be appended to SET and executed.


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.

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 maatkit manpage for full details.


You can download Maatkit from Google Code at <http://code.google.com/p/maatkit/>, or you can get any of the tools easily with a command like the following:

   wget http://www.maatkit.org/get/toolname
   wget http://www.maatkit.org/trunk/toolname

Where toolname can be replaced with the name (or fragment of a name) of any of the Maatkit tools.  Once downloaded, they're ready to run; no installation is needed.  The first URL gets the latest released version of the tool, and the second gets the latest trunk code from Subversion.


The environment variable MKDEBUG enables verbose debugging output in all of the Maatkit tools:

   MKDEBUG=1 mk-....

System Requirements

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 <http://www.maatkit.org/bugs/mk-slave-find>.

Please use Google Code Issues and Groups to report bugs or request support: <http://code.google.com/p/maatkit/>.  You can also join #maatkit on Freenode to discuss Maatkit.

Please include the complete command-line used to reproduce the problem you are seeing, the version of all MySQL servers involved, the complete output of the tool when run with "--version", and if possible, debugging output produced by running with the MKDEBUG=1 environment variable.

Copyright, License and Warranty

This program is copyright 2007-2011 Baron Schwartz. Feedback and improvements are welcome.


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.


Baron Schwartz

About Maatkit

This tool is part of Maatkit, a toolkit for power users of MySQL.  Maatkit was created by Baron Schwartz; Baron and Daniel Nichter are the primary code contributors.  Both are employed by Percona.  Financial support for Maatkit development is primarily provided by Percona and its clients.


This manual page documents Ver 1.0.16 Distrib 7540 $Revision: 7531 $.


2024-01-25 perl v5.38.2 User Contributed Perl Documentation