# ############################################################################

=pod

=head1 NAME

mk-heartbeat - Monitor MySQL replication delay.

=head1 OPTIONS

Specify at least one of L<"--stop">, --update, --monitor, or --check.

--update, --monitor, and --check are mutually exclusive.

--daemonize and --check are mutually exclusive.

=over

=item --array

type: array

An array.

=item --askpass

negatable: true

Prompts the user for a password when connecting to MySQL.

=item --charset

short form: -A; type: string

Default character set.

Enables character set settings in Perl and MySQL.  If the value is C<utf8>, sets
Perl's binmode on STDOUT to utf8, passes the C<mysql_enable_utf8> option to
DBD::mysql, and runs C<SET NAMES UTF8> after connecting to MySQL.  Any other
value sets binmode on STDOUT without the utf8 layer, and runs C<SET NAMES> after
connecting to MySQL.

=item --database

short form: -D; type: string

The database to use for the connection.

=item --interval

short form: -i; type: time; default: 1s

Interval L<"between"> C<updates> and checks.
Second line.

The updates and checks will happen when the Unix time (seconds since epoch) is
an even multiple of this value.  The default is one second.  The suffix is
similar to L<"--frames">.

=item --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 C<SET> command.

=item --size

short form: -s; type: size

Size.

=item --skew

short form: -k; type: int; default: 0

Delay --monitor checks this many usec.

How long to delay checks, in milliseconds.  The default is to delay checks one
half second.  Since the update happens as soon as possible after the beginning
of the second on the master, this allows one half second of replication delay
before reporting that the slave lags the master by one second.  If your clocks
are not completely accurate or there is some other reason you'd like to delay
the slave more or less, you can tweak this value.  Try setting the C<PTDEBUG>
environment variable to see the effect this has.

=item --verbose

short form: -v; cumulative: yes

Verbosity.

=item --hash

type: hash

Hash option

=item --hash2

type: Hash

Hash option forced.

=back

=head1 OTHER

The following options should not be parsed.

=over

=item --not-done-yet

This item is not part of the main option list and should not be read.

=back

=head1 ENVIRONMENT

The environment variable C<PTDEBUG> enables verbose debugging output in all of the
Maatkit tools:

   PTDEBUG=1 mk-....

=head1 SYSTEM REQUIREMENTS

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

=head1 SEE ALSO

See also L<mk-slave-delay> and L<mk-slave-restart>.

=head1 BUGS

Please use the Sourceforge bug tracker, forums, and mailing lists to request
support or report bugs: L<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 L<"--version">, and if possible, debugging output produced by
running with the C<PTDEBUG=1> environment variable.

=head1 COPYRIGHT, LICENSE AND WARRANTY

This program is copyright (c) 2006 Proven Scaling LLC and SixApart Ltd, and
(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.

=head1 AUTHOR

Proven Scaling LLC, SixApart Ltd, and Baron Schwartz.

=head1 VERSION

This manual page documents Ver @VERSION@ Distrib @DISTRIB@ $Revision: 1929 $.

=cut