NAME
DBIx::MySQL::Replication::Slave - Stop, start and monitor your slaves.
VERSION
version 0.02
SYNOPSIS
This module gives you an OO interface for stopping, starting and
monitoring the status and health of your MySQL slaves. It doesn't do
anything you can't already do for yourself, but it makes some basic
tasks just a little bit easier.
use DBIx::MySQL::Replication::Slave;
my $slave = DBIx::MySQL::Replication::Slave->new( dbh => $dbh );
if ( $slave->is_stopped ) {
$slave->start;
if ( $slave->is_running ) {
print "slave now running\n";
}
else {
print "cannot start stopped slave.\n";
}
}
If you need a quick monitor script:
$slave->max_seconds_behind_master( 30 );
if ( !$slave->slave_ok ) {
# send an alert to the administrator...
}
For some quick debugging:
use Data::Dump qw( dump );
print dump( $slave->status );
print "seconds behind: " . $slave->status->{seconds_behind_master};
CONSTRUCTOR AND STARTUP
new( dbh => $dbh )
Creates and returns a new DBIx::MySQL::Replication::Slave object.
my $slave = DBIx::MySQL::Replication::Slave->new( dbh => $dbh );
* "dbh => $dbh"
A valid database handle to your slave server is required. You'll
need to pass it to the constructor:
my $slave = DBIx::MySQL::Replication::Slave->new( dbh => $dbh );
Generally, the user will need to have the following MySQL
privileges:
SUPER,REPLICATION CLIENT
* "lc => 0|1"
By default, the status variables returned by MySQL are converted to
lower case. This is for readability. You may turn this off if you
wish, by explicitly turning it off when you create the object:
my $slave = DBIx::MySQL::Replication::Slave->new( dbh => $dbh, lc => 0 );
* "max_seconds_behind_master => $seconds"
By default this is set to a very generous number (86400 seconds).
Set this value if you'd like to take a shorter amount of time into
account when checking on your health. This is strongly recommended:
# Anything longer than 30 seconds is not acceptable
my $slave = DBIx::MySQL::Replication::Slave->new(
dbh => $dbh,
seconds_behind_master => 30
);
If you think it's cleaner, you can also set this value *after*
object creation.
$slave->max_seconds_behind_master(30);
SUBROUTINES/METHODS
status
Returns a HASHREF of the MySQL slave status variables. These vars will,
by default, be converted to lower case, unless you have turned this off
when you construct the object. See the lc option to new() for more info.
refresh_status
Issues a fresh "SLOW SLAVE STATUS" query and returns the new results of
$slave->status to you.
start
Issues a "START SLAVE" query and returns DBI's raw return value directly
to you.
stop
Issues a "STOP SLAVE" query and returns DBI's raw return value directly
to you.
slave_ok
This method returns true if slave_io_running and slave_sql_running are
both equal to 'Yes' AND if seconds_behind_master is <=
max_seconds_behind master.
is_running
Returns true if both slave_io_running and slave_sql_running are set to
'Yes'
is_stopped
Returns true if both slave_io_running and slave_sql_running are set to
'No'. If only one of these values returns 'Yes', it's probably fair to
say that the slave is in some transitional state. Neither stopped nor
running may be an accurate description in this case.
AUTHOR
Olaf Alders, "<olaf at wundercounter.com>"
BUGS AND LIMITATIONS
Please report any bugs or feature requests to
"bug-dbix-mysql-replication-slave at rt.cpan.org", or through the web
interface at
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=DBIx-MySQL-Replication-S
lave>. I will be notified, and then you'll automatically be notified of
progress on your bug as I make changes.
TESTING
Have a look at the source of t/connect.t if you'd like to do more
extensive testing of your install. This will require that you already
have a fully functional slave set up in order for the tests to pass.
These tests are skipped by default, but you are encouraged to run them
as part of your install process.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc DBIx::MySQL::Replication::Slave
You can also look for information at:
* GitHub Source Repository
<http://github.com/oalders/dbix-mysql-replication-slave>
* RT: CPAN's request tracker
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=DBIx-MySQL-Replication-Sla
ve>
* AnnoCPAN: Annotated CPAN documentation
<http://annocpan.org/dist/DBIx-MySQL-Replication-Slave>
* CPAN Ratings
<http://cpanratings.perl.org/d/DBIx-MySQL-Replication-Slave>
* Search CPAN
<http://search.cpan.org/dist/DBIx-MySQL-Replication-Slave/>
ACKNOWLEDGEMENTS
Thanks to Raybec Communications <http://www.raybec.com> for funding my
work on this module and for releasing it to the world.
LICENSE AND COPYRIGHT
Copyright 2010 Olaf Alders.
This program is free software; you can redistribute it and/or modify it
under the terms of either: the GNU General Public License as published
by the Free Software Foundation; or the Artistic License.
See http://dev.perl.org/licenses/ for more information.