Man page for mk-slave-move

August 24, 2007 – 5:31 pm

MK-SLAVE-MOVE

Section: User Contributed Perl Documentation (1)
Updated: 2008-06-01
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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.

DOWNLOADING

You can download Maatkit from the Sourceforge website at
<http://sourceforge.net/projects/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.

–askpass

Prompt for a password when connecting to MySQL.

–detach

Make this server forget that it is a slave.

–setvars

type: string; default: wait_timeout=10000

Set these MySQL variables.

Specify any variables you want to be set immediately after connecting to MySQL.
These will be included in a "SET" command.

–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.

–timeout

short option: -m; type: time; default: 10m

Timeout when waiting for replication to catch up.

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.

SYSTEM REQUIREMENTS

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

OUTPUT

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

If you find bugs, need features, etc please use the bug tracker, forums, and
mailing lists at http://sourceforge.net/projects/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 (c) 2007 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 0.9.1 Distrib 1972 $Revision: 1970 $.

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