MK-SLAVE-MOVE(1)

NAME
mk-slave-move - Move a MySQL slave around in the replication hierarchy.

SYNOPSIS
 mk-slave-move slave --sibling-of-master
 mk-slave-move slave --slave-of-sibling sibling
 mk-slave-move slave --slave-of-uncle uncle

DESCRIPTION
This tool knows how to disconnect and reconnect slaves to each other, compare replication positions, and so on. This makes it able to move a slave around the replication hierarchy safely and correctly. It doesn't do anything you can't do by hand, but it is tedious and error-prone to do this by hand.

Some of the features are incomplete, including some safety checks such as not moving slaves that have temporary tables open.

The slave host can be specified using one of two methods. The first method is to use at least one of the standard connection-related command line options: "--defaults-file", "--password", "--host", "--port", "--socket" or "--user". These options only apply to the slave host.

The second method to specifiy the slave host, or the sibling or uncle host, is a DSN. A DSN is a special syntax that can be either just a hostname (like "server.domain.com" or 1.2.3.4), or a "key=value,key=value" string. Keys are a single letter:

   KEY MEANING
   === =======
   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

If you omit any values in the sibling or uncle host, they are filled in with defaults from the slave host, so you don't need to specify them in both places. "mk-slave-move" 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.

DOWNLOADING
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
   or
   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.

OPTIONS
Specify one and only one of --sibling-of-master, --slave-of-sibling, --slave-of-uncle, or --detach.

--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.

--config
    type: Array

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

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

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

--detach
    Make this server forget that it is a slave.

--help
    Show help and exit.

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

    Connect to host.

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

    Password to use when connecting.

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

    Port number to use for connection.

--set-vars
    type: string; default: wait_timeout=10000

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

--sibling-of-master
    Make the server a slave of its grandparent, so it is a sibling of its master.

    The procedure is as follows:

     1. Connect to the server's master.
     2. Stop the slave processes on the master.
     3. Wait for the server to catch up to its master in replication.
     4. Point the slave to the master's master.

--slave-of-sibling
    Make the server a slave of one of its siblings. Specify the sibling as a DSN.

    The procedure is as follows:

     1. Connect to the sibling and verify that it has the same master.
     2. Stop the slave processes on the server and its sibling.
     3. If one of the servers is behind the other, make it catch up.
     4. Point the slave to its sibling.

--slave-of-uncle
    Make the server a slave of one of its uncles (parent's siblings). Specify the uncle as a DSN.

    An "uncle" is a sibling of the server's master. The procedure is as follows:

     1. Connect to the slave's master and its uncle, and verify that both have the
        same master.  (Their common master is the slave's grandparent).
     2. Stop the slave processes on the master and uncle.
     3. If one of them is behind the other, make it catch up.
     4. Point the slave to its uncle.

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

    Socket file to use for connection.

--timeout
    type: time; default: 10m

    Timeout when waiting for replication to catch up.

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

    User for login if not current user.

--version
    Show version and exit.

TODO
The following options are not implemented yet.

--promote
    Make the server a slave of its grandparent, if any, and then make all of its previous siblings its slaves. If extra DSNs are given on the command-line, use these as its siblings; otherwise discover siblings by examining its master.

--resume
    Start the slave running after moving it. Default is to leave the slave stopped. TODO: this option is not implemented yet.

--slave-of-master
    TODO: change to current master. Can be useful for throwing away corrupt relay logs, for example. Note: must check error log and see what the real position of the log file is. http://www.pythian.com/blogs/876/when-show-slave-status-and-the-error-log-disagree

--read-only
    TODO: detect read-only setting and change it after moving servers.

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

EXIT STATUS
Successful exit status is 0. Any other value represents the exit status of the Perl process itself.

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

   MKDEBUG=1 mk-....

BUGS
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.

SEE ALSO
See also mk-table-checksum, mk-table-sync, mk-slave-delay.

COPYRIGHT, LICENSE AND WARRANTY
This program is copyright 2007-2009 Baron Schwartz. Feedback and improvements are welcome.

THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY 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.

AUTHOR
Baron Schwartz

VERSION
This manual page documents Ver 0.9.7 Distrib 4047 $Revision: 3965 $.