maatkit 7540-1 / usr / bin / mk-slave-restart

#!/usr/bin/env perl

# This is mk-slave-restart, a program to watch replication and try to
# restart slaves on errors.
#
# This program is copyright 2007-2011 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
# MERCHANTABILITY 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.

use strict;
use warnings FATAL => 'all';

our $VERSION = '1.0.22';
our $DISTRIB = '7540';
our $SVN_REV = sprintf("%d", (q$Revision: 7531 $ =~ m/(\d+)/g, 0));

# ###########################################################################
# Quoter package 6850
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the SVN repository at,
#   trunk/common/Quoter.pm
#   trunk/common/t/Quoter.t
# See http://code.google.com/p/maatkit/wiki/Developers for more information.
# ###########################################################################

package Quoter;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);

use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class, %args ) = @_;
   return bless {}, $class;
}

sub quote {
   my ( $self, @vals ) = @_;
   foreach my $val ( @vals ) {
      $val =~ s/`/``/g;
   }
   return join('.', map { '`' . $_ . '`' } @vals);
}

sub quote_val {
   my ( $self, $val ) = @_;

   return 'NULL' unless defined $val;          # undef = NULL
   return "''" if $val eq '';                  # blank string = ''
   return $val if $val =~ m/^0x[0-9a-fA-F]+$/;  # hex data

   $val =~ s/(['\\])/\\$1/g;
   return "'$val'";
}

sub split_unquote {
   my ( $self, $db_tbl, $default_db ) = @_;
   $db_tbl =~ s/`//g;
   my ( $db, $tbl ) = split(/[.]/, $db_tbl);
   if ( !$tbl ) {
      $tbl = $db;
      $db  = $default_db;
   }
   return ($db, $tbl);
}

sub literal_like {
   my ( $self, $like ) = @_;
   return unless $like;
   $like =~ s/([%_])/\\$1/g;
   return "'$like'";
}

sub join_quote {
   my ( $self, $default_db, $db_tbl ) = @_;
   return unless $db_tbl;
   my ($db, $tbl) = split(/[.]/, $db_tbl);
   if ( !$tbl ) {
      $tbl = $db;
      $db  = $default_db;
   }
   $db  = "`$db`"  if $db  && $db  !~ m/^`/;
   $tbl = "`$tbl`" if $tbl && $tbl !~ m/^`/;
   return $db ? "$db.$tbl" : $tbl;
}

1;

# ###########################################################################
# End Quoter package
# ###########################################################################

# ###########################################################################
# OptionParser package 7102
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the SVN repository at,
#   trunk/common/OptionParser.pm
#   trunk/common/t/OptionParser.t
# See http://code.google.com/p/maatkit/wiki/Developers for more information.
# ###########################################################################

package OptionParser;

use strict;
use warnings FATAL => 'all';
use List::Util qw(max);
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use Getopt::Long;

my $POD_link_re = '[LC]<"?([^">]+)"?>';

sub new {
   my ( $class, %args ) = @_;
   my @required_args = qw();
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }

   my ($program_name) = $PROGRAM_NAME =~ m/([.A-Za-z-]+)$/;
   $program_name ||= $PROGRAM_NAME;
   my $home = $ENV{HOME} || $ENV{HOMEPATH} || $ENV{USERPROFILE} || '.';

   my %attributes = (
      'type'       => 1,
      'short form' => 1,
      'group'      => 1,
      'default'    => 1,
      'cumulative' => 1,
      'negatable'  => 1,
   );

   my $self = {
      head1             => 'OPTIONS',        # These args are used internally
      skip_rules        => 0,                # to instantiate another Option-
      item              => '--(.*)',         # Parser obj that parses the
      attributes        => \%attributes,     # DSN OPTIONS section.  Tools
      parse_attributes  => \&_parse_attribs, # don't tinker with these args.

      %args,

      strict            => 1,  # disabled by a special rule
      program_name      => $program_name,
      opts              => {},
      got_opts          => 0,
      short_opts        => {},
      defaults          => {},
      groups            => {},
      allowed_groups    => {},
      errors            => [],
      rules             => [],  # desc of rules for --help
      mutex             => [],  # rule: opts are mutually exclusive
      atleast1          => [],  # rule: at least one opt is required
      disables          => {},  # rule: opt disables other opts 
      defaults_to       => {},  # rule: opt defaults to value of other opt
      DSNParser         => undef,
      default_files     => [
         "/etc/maatkit/maatkit.conf",
         "/etc/maatkit/$program_name.conf",
         "$home/.maatkit.conf",
         "$home/.$program_name.conf",
      ],
      types             => {
         string => 's', # standard Getopt type
         int    => 'i', # standard Getopt type
         float  => 'f', # standard Getopt type
         Hash   => 'H', # hash, formed from a comma-separated list
         hash   => 'h', # hash as above, but only if a value is given
         Array  => 'A', # array, similar to Hash
         array  => 'a', # array, similar to hash
         DSN    => 'd', # DSN
         size   => 'z', # size with kMG suffix (powers of 2^10)
         time   => 'm', # time, with an optional suffix of s/h/m/d
      },
   };

   return bless $self, $class;
}

sub get_specs {
   my ( $self, $file ) = @_;
   $file ||= $self->{file} || __FILE__;
   my @specs = $self->_pod_to_specs($file);
   $self->_parse_specs(@specs);

   open my $fh, "<", $file or die "Cannot open $file: $OS_ERROR";
   my $contents = do { local $/ = undef; <$fh> };
   close $fh;
   if ( $contents =~ m/^=head1 DSN OPTIONS/m ) {
      MKDEBUG && _d('Parsing DSN OPTIONS');
      my $dsn_attribs = {
         dsn  => 1,
         copy => 1,
      };
      my $parse_dsn_attribs = sub {
         my ( $self, $option, $attribs ) = @_;
         map {
            my $val = $attribs->{$_};
            if ( $val ) {
               $val    = $val eq 'yes' ? 1
                       : $val eq 'no'  ? 0
                       :                 $val;
               $attribs->{$_} = $val;
            }
         } keys %$attribs;
         return {
            key => $option,
            %$attribs,
         };
      };
      my $dsn_o = new OptionParser(
         description       => 'DSN OPTIONS',
         head1             => 'DSN OPTIONS',
         dsn               => 0,         # XXX don't infinitely recurse!
         item              => '\* (.)',  # key opts are a single character
         skip_rules        => 1,         # no rules before opts
         attributes        => $dsn_attribs,
         parse_attributes  => $parse_dsn_attribs,
      );
      my @dsn_opts = map {
         my $opts = {
            key  => $_->{spec}->{key},
            dsn  => $_->{spec}->{dsn},
            copy => $_->{spec}->{copy},
            desc => $_->{desc},
         };
         $opts;
      } $dsn_o->_pod_to_specs($file);
      $self->{DSNParser} = DSNParser->new(opts => \@dsn_opts);
   }

   return;
}

sub DSNParser {
   my ( $self ) = @_;
   return $self->{DSNParser};
};

sub get_defaults_files {
   my ( $self ) = @_;
   return @{$self->{default_files}};
}

sub _pod_to_specs {
   my ( $self, $file ) = @_;
   $file ||= $self->{file} || __FILE__;
   open my $fh, '<', $file or die "Cannot open $file: $OS_ERROR";

   my @specs = ();
   my @rules = ();
   my $para;

   local $INPUT_RECORD_SEPARATOR = '';
   while ( $para = <$fh> ) {
      next unless $para =~ m/^=head1 $self->{head1}/;
      last;
   }

   while ( $para = <$fh> ) {
      last if $para =~ m/^=over/;
      next if $self->{skip_rules};
      chomp $para;
      $para =~ s/\s+/ /g;
      $para =~ s/$POD_link_re/$1/go;
      MKDEBUG && _d('Option rule:', $para);
      push @rules, $para;
   }

   die "POD has no $self->{head1} section" unless $para;

   do {
      if ( my ($option) = $para =~ m/^=item $self->{item}/ ) {
         chomp $para;
         MKDEBUG && _d($para);
         my %attribs;

         $para = <$fh>; # read next paragraph, possibly attributes

         if ( $para =~ m/: / ) { # attributes
            $para =~ s/\s+\Z//g;
            %attribs = map {
                  my ( $attrib, $val) = split(/: /, $_);
                  die "Unrecognized attribute for --$option: $attrib"
                     unless $self->{attributes}->{$attrib};
                  ($attrib, $val);
               } split(/; /, $para);
            if ( $attribs{'short form'} ) {
               $attribs{'short form'} =~ s/-//;
            }
            $para = <$fh>; # read next paragraph, probably short help desc
         }
         else {
            MKDEBUG && _d('Option has no attributes');
         }

         $para =~ s/\s+\Z//g;
         $para =~ s/\s+/ /g;
         $para =~ s/$POD_link_re/$1/go;

         $para =~ s/\.(?:\n.*| [A-Z].*|\Z)//s;
         MKDEBUG && _d('Short help:', $para);

         die "No description after option spec $option" if $para =~ m/^=item/;

         if ( my ($base_option) =  $option =~ m/^\[no\](.*)/ ) {
            $option = $base_option;
            $attribs{'negatable'} = 1;
         }

         push @specs, {
            spec  => $self->{parse_attributes}->($self, $option, \%attribs), 
            desc  => $para
               . (defined $attribs{default} ? " (default $attribs{default})" : ''),
            group => ($attribs{'group'} ? $attribs{'group'} : 'default'),
         };
      }
      while ( $para = <$fh> ) {
         last unless $para;
         if ( $para =~ m/^=head1/ ) {
            $para = undef; # Can't 'last' out of a do {} block.
            last;
         }
         last if $para =~ m/^=item /;
      }
   } while ( $para );

   die "No valid specs in $self->{head1}" unless @specs;

   close $fh;
   return @specs, @rules;
}

sub _parse_specs {
   my ( $self, @specs ) = @_;
   my %disables; # special rule that requires deferred checking

   foreach my $opt ( @specs ) {
      if ( ref $opt ) { # It's an option spec, not a rule.
         MKDEBUG && _d('Parsing opt spec:',
            map { ($_, '=>', $opt->{$_}) } keys %$opt);

         my ( $long, $short ) = $opt->{spec} =~ m/^([\w-]+)(?:\|([^!+=]*))?/;
         if ( !$long ) {
            die "Cannot parse long option from spec $opt->{spec}";
         }
         $opt->{long} = $long;

         die "Duplicate long option --$long" if exists $self->{opts}->{$long};
         $self->{opts}->{$long} = $opt;

         if ( length $long == 1 ) {
            MKDEBUG && _d('Long opt', $long, 'looks like short opt');
            $self->{short_opts}->{$long} = $long;
         }

         if ( $short ) {
            die "Duplicate short option -$short"
               if exists $self->{short_opts}->{$short};
            $self->{short_opts}->{$short} = $long;
            $opt->{short} = $short;
         }
         else {
            $opt->{short} = undef;
         }

         $opt->{is_negatable}  = $opt->{spec} =~ m/!/        ? 1 : 0;
         $opt->{is_cumulative} = $opt->{spec} =~ m/\+/       ? 1 : 0;
         $opt->{is_required}   = $opt->{desc} =~ m/required/ ? 1 : 0;

         $opt->{group} ||= 'default';
         $self->{groups}->{ $opt->{group} }->{$long} = 1;

         $opt->{value} = undef;
         $opt->{got}   = 0;

         my ( $type ) = $opt->{spec} =~ m/=(.)/;
         $opt->{type} = $type;
         MKDEBUG && _d($long, 'type:', $type);


         $opt->{spec} =~ s/=./=s/ if ( $type && $type =~ m/[HhAadzm]/ );

         if ( (my ($def) = $opt->{desc} =~ m/default\b(?: ([^)]+))?/) ) {
            $self->{defaults}->{$long} = defined $def ? $def : 1;
            MKDEBUG && _d($long, 'default:', $def);
         }

         if ( $long eq 'config' ) {
            $self->{defaults}->{$long} = join(',', $self->get_defaults_files());
         }

         if ( (my ($dis) = $opt->{desc} =~ m/(disables .*)/) ) {
            $disables{$long} = $dis;
            MKDEBUG && _d('Deferring check of disables rule for', $opt, $dis);
         }

         $self->{opts}->{$long} = $opt;
      }
      else { # It's an option rule, not a spec.
         MKDEBUG && _d('Parsing rule:', $opt); 
         push @{$self->{rules}}, $opt;
         my @participants = $self->_get_participants($opt);
         my $rule_ok = 0;

         if ( $opt =~ m/mutually exclusive|one and only one/ ) {
            $rule_ok = 1;
            push @{$self->{mutex}}, \@participants;
            MKDEBUG && _d(@participants, 'are mutually exclusive');
         }
         if ( $opt =~ m/at least one|one and only one/ ) {
            $rule_ok = 1;
            push @{$self->{atleast1}}, \@participants;
            MKDEBUG && _d(@participants, 'require at least one');
         }
         if ( $opt =~ m/default to/ ) {
            $rule_ok = 1;
            $self->{defaults_to}->{$participants[0]} = $participants[1];
            MKDEBUG && _d($participants[0], 'defaults to', $participants[1]);
         }
         if ( $opt =~ m/restricted to option groups/ ) {
            $rule_ok = 1;
            my ($groups) = $opt =~ m/groups ([\w\s\,]+)/;
            my @groups = split(',', $groups);
            %{$self->{allowed_groups}->{$participants[0]}} = map {
               s/\s+//;
               $_ => 1;
            } @groups;
         }
         if( $opt =~ m/accepts additional command-line arguments/ ) {
            $rule_ok = 1;
            $self->{strict} = 0;
            MKDEBUG && _d("Strict mode disabled by rule");
         }

         die "Unrecognized option rule: $opt" unless $rule_ok;
      }
   }

   foreach my $long ( keys %disables ) {
      my @participants = $self->_get_participants($disables{$long});
      $self->{disables}->{$long} = \@participants;
      MKDEBUG && _d('Option', $long, 'disables', @participants);
   }

   return; 
}

sub _get_participants {
   my ( $self, $str ) = @_;
   my @participants;
   foreach my $long ( $str =~ m/--(?:\[no\])?([\w-]+)/g ) {
      die "Option --$long does not exist while processing rule $str"
         unless exists $self->{opts}->{$long};
      push @participants, $long;
   }
   MKDEBUG && _d('Participants for', $str, ':', @participants);
   return @participants;
}

sub opts {
   my ( $self ) = @_;
   my %opts = %{$self->{opts}};
   return %opts;
}

sub short_opts {
   my ( $self ) = @_;
   my %short_opts = %{$self->{short_opts}};
   return %short_opts;
}

sub set_defaults {
   my ( $self, %defaults ) = @_;
   $self->{defaults} = {};
   foreach my $long ( keys %defaults ) {
      die "Cannot set default for nonexistent option $long"
         unless exists $self->{opts}->{$long};
      $self->{defaults}->{$long} = $defaults{$long};
      MKDEBUG && _d('Default val for', $long, ':', $defaults{$long});
   }
   return;
}

sub get_defaults {
   my ( $self ) = @_;
   return $self->{defaults};
}

sub get_groups {
   my ( $self ) = @_;
   return $self->{groups};
}

sub _set_option {
   my ( $self, $opt, $val ) = @_;
   my $long = exists $self->{opts}->{$opt}       ? $opt
            : exists $self->{short_opts}->{$opt} ? $self->{short_opts}->{$opt}
            : die "Getopt::Long gave a nonexistent option: $opt";

   $opt = $self->{opts}->{$long};
   if ( $opt->{is_cumulative} ) {
      $opt->{value}++;
   }
   else {
      $opt->{value} = $val;
   }
   $opt->{got} = 1;
   MKDEBUG && _d('Got option', $long, '=', $val);
}

sub get_opts {
   my ( $self ) = @_; 

   foreach my $long ( keys %{$self->{opts}} ) {
      $self->{opts}->{$long}->{got} = 0;
      $self->{opts}->{$long}->{value}
         = exists $self->{defaults}->{$long}       ? $self->{defaults}->{$long}
         : $self->{opts}->{$long}->{is_cumulative} ? 0
         : undef;
   }
   $self->{got_opts} = 0;

   $self->{errors} = [];

   if ( @ARGV && $ARGV[0] eq "--config" ) {
      shift @ARGV;
      $self->_set_option('config', shift @ARGV);
   }
   if ( $self->has('config') ) {
      my @extra_args;
      foreach my $filename ( split(',', $self->get('config')) ) {
         eval {
            push @extra_args, $self->_read_config_file($filename);
         };
         if ( $EVAL_ERROR ) {
            if ( $self->got('config') ) {
               die $EVAL_ERROR;
            }
            elsif ( MKDEBUG ) {
               _d($EVAL_ERROR);
            }
         }
      }
      unshift @ARGV, @extra_args;
   }

   Getopt::Long::Configure('no_ignore_case', 'bundling');
   GetOptions(
      map    { $_->{spec} => sub { $self->_set_option(@_); } }
      grep   { $_->{long} ne 'config' } # --config is handled specially above.
      values %{$self->{opts}}
   ) or $self->save_error('Error parsing options');

   if ( exists $self->{opts}->{version} && $self->{opts}->{version}->{got} ) {
      printf("%s  Ver %s Distrib %s Changeset %s\n",
         $self->{program_name}, $main::VERSION, $main::DISTRIB, $main::SVN_REV)
            or die "Cannot print: $OS_ERROR";
      exit 0;
   }

   if ( @ARGV && $self->{strict} ) {
      $self->save_error("Unrecognized command-line options @ARGV");
   }

   foreach my $mutex ( @{$self->{mutex}} ) {
      my @set = grep { $self->{opts}->{$_}->{got} } @$mutex;
      if ( @set > 1 ) {
         my $err = join(', ', map { "--$self->{opts}->{$_}->{long}" }
                      @{$mutex}[ 0 .. scalar(@$mutex) - 2] )
                 . ' and --'.$self->{opts}->{$mutex->[-1]}->{long}
                 . ' are mutually exclusive.';
         $self->save_error($err);
      }
   }

   foreach my $required ( @{$self->{atleast1}} ) {
      my @set = grep { $self->{opts}->{$_}->{got} } @$required;
      if ( @set == 0 ) {
         my $err = join(', ', map { "--$self->{opts}->{$_}->{long}" }
                      @{$required}[ 0 .. scalar(@$required) - 2] )
                 .' or --'.$self->{opts}->{$required->[-1]}->{long};
         $self->save_error("Specify at least one of $err");
      }
   }

   $self->_check_opts( keys %{$self->{opts}} );
   $self->{got_opts} = 1;
   return;
}

sub _check_opts {
   my ( $self, @long ) = @_;
   my $long_last = scalar @long;
   while ( @long ) {
      foreach my $i ( 0..$#long ) {
         my $long = $long[$i];
         next unless $long;
         my $opt  = $self->{opts}->{$long};
         if ( $opt->{got} ) {
            if ( exists $self->{disables}->{$long} ) {
               my @disable_opts = @{$self->{disables}->{$long}};
               map { $self->{opts}->{$_}->{value} = undef; } @disable_opts;
               MKDEBUG && _d('Unset options', @disable_opts,
                  'because', $long,'disables them');
            }

            if ( exists $self->{allowed_groups}->{$long} ) {

               my @restricted_groups = grep {
                  !exists $self->{allowed_groups}->{$long}->{$_}
               } keys %{$self->{groups}};

               my @restricted_opts;
               foreach my $restricted_group ( @restricted_groups ) {
                  RESTRICTED_OPT:
                  foreach my $restricted_opt (
                     keys %{$self->{groups}->{$restricted_group}} )
                  {
                     next RESTRICTED_OPT if $restricted_opt eq $long;
                     push @restricted_opts, $restricted_opt
                        if $self->{opts}->{$restricted_opt}->{got};
                  }
               }

               if ( @restricted_opts ) {
                  my $err;
                  if ( @restricted_opts == 1 ) {
                     $err = "--$restricted_opts[0]";
                  }
                  else {
                     $err = join(', ',
                               map { "--$self->{opts}->{$_}->{long}" }
                               grep { $_ } 
                               @restricted_opts[0..scalar(@restricted_opts) - 2]
                            )
                          . ' or --'.$self->{opts}->{$restricted_opts[-1]}->{long};
                  }
                  $self->save_error("--$long is not allowed with $err");
               }
            }

         }
         elsif ( $opt->{is_required} ) { 
            $self->save_error("Required option --$long must be specified");
         }

         $self->_validate_type($opt);
         if ( $opt->{parsed} ) {
            delete $long[$i];
         }
         else {
            MKDEBUG && _d('Temporarily failed to parse', $long);
         }
      }

      die "Failed to parse options, possibly due to circular dependencies"
         if @long == $long_last;
      $long_last = @long;
   }

   return;
}

sub _validate_type {
   my ( $self, $opt ) = @_;
   return unless $opt;

   if ( !$opt->{type} ) {
      $opt->{parsed} = 1;
      return;
   }

   my $val = $opt->{value};

   if ( $val && $opt->{type} eq 'm' ) {  # type time
      MKDEBUG && _d('Parsing option', $opt->{long}, 'as a time value');
      my ( $prefix, $num, $suffix ) = $val =~ m/([+-]?)(\d+)([a-z])?$/;
      if ( !$suffix ) {
         my ( $s ) = $opt->{desc} =~ m/\(suffix (.)\)/;
         $suffix = $s || 's';
         MKDEBUG && _d('No suffix given; using', $suffix, 'for',
            $opt->{long}, '(value:', $val, ')');
      }
      if ( $suffix =~ m/[smhd]/ ) {
         $val = $suffix eq 's' ? $num            # Seconds
              : $suffix eq 'm' ? $num * 60       # Minutes
              : $suffix eq 'h' ? $num * 3600     # Hours
              :                  $num * 86400;   # Days
         $opt->{value} = ($prefix || '') . $val;
         MKDEBUG && _d('Setting option', $opt->{long}, 'to', $val);
      }
      else {
         $self->save_error("Invalid time suffix for --$opt->{long}");
      }
   }
   elsif ( $val && $opt->{type} eq 'd' ) {  # type DSN
      MKDEBUG && _d('Parsing option', $opt->{long}, 'as a DSN');
      my $prev = {};
      my $from_key = $self->{defaults_to}->{ $opt->{long} };
      if ( $from_key ) {
         MKDEBUG && _d($opt->{long}, 'DSN copies from', $from_key, 'DSN');
         if ( $self->{opts}->{$from_key}->{parsed} ) {
            $prev = $self->{opts}->{$from_key}->{value};
         }
         else {
            MKDEBUG && _d('Cannot parse', $opt->{long}, 'until',
               $from_key, 'parsed');
            return;
         }
      }
      my $defaults = $self->{DSNParser}->parse_options($self);
      $opt->{value} = $self->{DSNParser}->parse($val, $prev, $defaults);
   }
   elsif ( $val && $opt->{type} eq 'z' ) {  # type size
      MKDEBUG && _d('Parsing option', $opt->{long}, 'as a size value');
      $self->_parse_size($opt, $val);
   }
   elsif ( $opt->{type} eq 'H' || (defined $val && $opt->{type} eq 'h') ) {
      $opt->{value} = { map { $_ => 1 } split(/(?<!\\),\s*/, ($val || '')) };
   }
   elsif ( $opt->{type} eq 'A' || (defined $val && $opt->{type} eq 'a') ) {
      $opt->{value} = [ split(/(?<!\\),\s*/, ($val || '')) ];
   }
   else {
      MKDEBUG && _d('Nothing to validate for option',
         $opt->{long}, 'type', $opt->{type}, 'value', $val);
   }

   $opt->{parsed} = 1;
   return;
}

sub get {
   my ( $self, $opt ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   die "Option $opt does not exist"
      unless $long && exists $self->{opts}->{$long};
   return $self->{opts}->{$long}->{value};
}

sub got {
   my ( $self, $opt ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   die "Option $opt does not exist"
      unless $long && exists $self->{opts}->{$long};
   return $self->{opts}->{$long}->{got};
}

sub has {
   my ( $self, $opt ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   return defined $long ? exists $self->{opts}->{$long} : 0;
}

sub set {
   my ( $self, $opt, $val ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   die "Option $opt does not exist"
      unless $long && exists $self->{opts}->{$long};
   $self->{opts}->{$long}->{value} = $val;
   return;
}

sub save_error {
   my ( $self, $error ) = @_;
   push @{$self->{errors}}, $error;
   return;
}

sub errors {
   my ( $self ) = @_;
   return $self->{errors};
}

sub usage {
   my ( $self ) = @_;
   warn "No usage string is set" unless $self->{usage}; # XXX
   return "Usage: " . ($self->{usage} || '') . "\n";
}

sub descr {
   my ( $self ) = @_;
   warn "No description string is set" unless $self->{description}; # XXX
   my $descr  = ($self->{description} || $self->{program_name} || '')
              . "  For more details, please use the --help option, "
              . "or try 'perldoc $PROGRAM_NAME' "
              . "for complete documentation.";
   $descr = join("\n", $descr =~ m/(.{0,80})(?:\s+|$)/g)
      unless $ENV{DONT_BREAK_LINES};
   $descr =~ s/ +$//mg;
   return $descr;
}

sub usage_or_errors {
   my ( $self, $file, $return ) = @_;
   $file ||= $self->{file} || __FILE__;

   if ( !$self->{description} || !$self->{usage} ) {
      MKDEBUG && _d("Getting description and usage from SYNOPSIS in", $file);
      my %synop = $self->_parse_synopsis($file);
      $self->{description} ||= $synop{description};
      $self->{usage}       ||= $synop{usage};
      MKDEBUG && _d("Description:", $self->{description},
         "\nUsage:", $self->{usage});
   }

   if ( $self->{opts}->{help}->{got} ) {
      print $self->print_usage() or die "Cannot print usage: $OS_ERROR";
      exit 0 unless $return;
   }
   elsif ( scalar @{$self->{errors}} ) {
      print $self->print_errors() or die "Cannot print errors: $OS_ERROR";
      exit 0 unless $return;
   }

   return;
}

sub print_errors {
   my ( $self ) = @_;
   my $usage = $self->usage() . "\n";
   if ( (my @errors = @{$self->{errors}}) ) {
      $usage .= join("\n  * ", 'Errors in command-line arguments:', @errors)
              . "\n";
   }
   return $usage . "\n" . $self->descr();
}

sub print_usage {
   my ( $self ) = @_;
   die "Run get_opts() before print_usage()" unless $self->{got_opts};
   my @opts = values %{$self->{opts}};

   my $maxl = max(
      map {
         length($_->{long})               # option long name
         + ($_->{is_negatable} ? 4 : 0)   # "[no]" if opt is negatable
         + ($_->{type} ? 2 : 0)           # "=x" where x is the opt type
      }
      @opts);

   my $maxs = max(0,
      map {
         length($_)
         + ($self->{opts}->{$_}->{is_negatable} ? 4 : 0)
         + ($self->{opts}->{$_}->{type} ? 2 : 0)
      }
      values %{$self->{short_opts}});

   my $lcol = max($maxl, ($maxs + 3));
   my $rcol = 80 - $lcol - 6;
   my $rpad = ' ' x ( 80 - $rcol );

   $maxs = max($lcol - 3, $maxs);

   my $usage = $self->descr() . "\n" . $self->usage();

   my @groups = reverse sort grep { $_ ne 'default'; } keys %{$self->{groups}};
   push @groups, 'default';

   foreach my $group ( reverse @groups ) {
      $usage .= "\n".($group eq 'default' ? 'Options' : $group).":\n\n";
      foreach my $opt (
         sort { $a->{long} cmp $b->{long} }
         grep { $_->{group} eq $group }
         @opts )
      {
         my $long  = $opt->{is_negatable} ? "[no]$opt->{long}" : $opt->{long};
         my $short = $opt->{short};
         my $desc  = $opt->{desc};

         $long .= $opt->{type} ? "=$opt->{type}" : "";

         if ( $opt->{type} && $opt->{type} eq 'm' ) {
            my ($s) = $desc =~ m/\(suffix (.)\)/;
            $s    ||= 's';
            $desc =~ s/\s+\(suffix .\)//;
            $desc .= ".  Optional suffix s=seconds, m=minutes, h=hours, "
                   . "d=days; if no suffix, $s is used.";
         }
         $desc = join("\n$rpad", grep { $_ } $desc =~ m/(.{0,$rcol})(?:\s+|$)/g);
         $desc =~ s/ +$//mg;
         if ( $short ) {
            $usage .= sprintf("  --%-${maxs}s -%s  %s\n", $long, $short, $desc);
         }
         else {
            $usage .= sprintf("  --%-${lcol}s  %s\n", $long, $desc);
         }
      }
   }

   $usage .= "\nOption types: s=string, i=integer, f=float, h/H/a/A=comma-separated list, d=DSN, z=size, m=time\n";

   if ( (my @rules = @{$self->{rules}}) ) {
      $usage .= "\nRules:\n\n";
      $usage .= join("\n", map { "  $_" } @rules) . "\n";
   }
   if ( $self->{DSNParser} ) {
      $usage .= "\n" . $self->{DSNParser}->usage();
   }
   $usage .= "\nOptions and values after processing arguments:\n\n";
   foreach my $opt ( sort { $a->{long} cmp $b->{long} } @opts ) {
      my $val   = $opt->{value};
      my $type  = $opt->{type} || '';
      my $bool  = $opt->{spec} =~ m/^[\w-]+(?:\|[\w-])?!?$/;
      $val      = $bool              ? ( $val ? 'TRUE' : 'FALSE' )
                : !defined $val      ? '(No value)'
                : $type eq 'd'       ? $self->{DSNParser}->as_string($val)
                : $type =~ m/H|h/    ? join(',', sort keys %$val)
                : $type =~ m/A|a/    ? join(',', @$val)
                :                    $val;
      $usage .= sprintf("  --%-${lcol}s  %s\n", $opt->{long}, $val);
   }
   return $usage;
}

sub prompt_noecho {
   shift @_ if ref $_[0] eq __PACKAGE__;
   my ( $prompt ) = @_;
   local $OUTPUT_AUTOFLUSH = 1;
   print $prompt
      or die "Cannot print: $OS_ERROR";
   my $response;
   eval {
      require Term::ReadKey;
      Term::ReadKey::ReadMode('noecho');
      chomp($response = <STDIN>);
      Term::ReadKey::ReadMode('normal');
      print "\n"
         or die "Cannot print: $OS_ERROR";
   };
   if ( $EVAL_ERROR ) {
      die "Cannot read response; is Term::ReadKey installed? $EVAL_ERROR";
   }
   return $response;
}

if ( MKDEBUG ) {
   print '# ', $^X, ' ', $], "\n";
   my $uname = `uname -a`;
   if ( $uname ) {
      $uname =~ s/\s+/ /g;
      print "# $uname\n";
   }
   printf("# %s  Ver %s Distrib %s Changeset %s line %d\n",
      $PROGRAM_NAME, ($main::VERSION || ''), ($main::DISTRIB || ''),
      ($main::SVN_REV || ''), __LINE__);
   print('# Arguments: ',
      join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n");
}

sub _read_config_file {
   my ( $self, $filename ) = @_;
   open my $fh, "<", $filename or die "Cannot open $filename: $OS_ERROR\n";
   my @args;
   my $prefix = '--';
   my $parse  = 1;

   LINE:
   while ( my $line = <$fh> ) {
      chomp $line;
      next LINE if $line =~ m/^\s*(?:\#|\;|$)/;
      $line =~ s/\s+#.*$//g;
      $line =~ s/^\s+|\s+$//g;
      if ( $line eq '--' ) {
         $prefix = '';
         $parse  = 0;
         next LINE;
      }
      if ( $parse
         && (my($opt, $arg) = $line =~ m/^\s*([^=\s]+?)(?:\s*=\s*(.*?)\s*)?$/)
      ) {
         push @args, grep { defined $_ } ("$prefix$opt", $arg);
      }
      elsif ( $line =~ m/./ ) {
         push @args, $line;
      }
      else {
         die "Syntax error in file $filename at line $INPUT_LINE_NUMBER";
      }
   }
   close $fh;
   return @args;
}

sub read_para_after {
   my ( $self, $file, $regex ) = @_;
   open my $fh, "<", $file or die "Can't open $file: $OS_ERROR";
   local $INPUT_RECORD_SEPARATOR = '';
   my $para;
   while ( $para = <$fh> ) {
      next unless $para =~ m/^=pod$/m;
      last;
   }
   while ( $para = <$fh> ) {
      next unless $para =~ m/$regex/;
      last;
   }
   $para = <$fh>;
   chomp($para);
   close $fh or die "Can't close $file: $OS_ERROR";
   return $para;
}

sub clone {
   my ( $self ) = @_;

   my %clone = map {
      my $hashref  = $self->{$_};
      my $val_copy = {};
      foreach my $key ( keys %$hashref ) {
         my $ref = ref $hashref->{$key};
         $val_copy->{$key} = !$ref           ? $hashref->{$key}
                           : $ref eq 'HASH'  ? { %{$hashref->{$key}} }
                           : $ref eq 'ARRAY' ? [ @{$hashref->{$key}} ]
                           : $hashref->{$key};
      }
      $_ => $val_copy;
   } qw(opts short_opts defaults);

   foreach my $scalar ( qw(got_opts) ) {
      $clone{$scalar} = $self->{$scalar};
   }

   return bless \%clone;     
}

sub _parse_size {
   my ( $self, $opt, $val ) = @_;

   if ( lc($val || '') eq 'null' ) {
      MKDEBUG && _d('NULL size for', $opt->{long});
      $opt->{value} = 'null';
      return;
   }

   my %factor_for = (k => 1_024, M => 1_048_576, G => 1_073_741_824);
   my ($pre, $num, $factor) = $val =~ m/^([+-])?(\d+)([kMG])?$/;
   if ( defined $num ) {
      if ( $factor ) {
         $num *= $factor_for{$factor};
         MKDEBUG && _d('Setting option', $opt->{y},
            'to num', $num, '* factor', $factor);
      }
      $opt->{value} = ($pre || '') . $num;
   }
   else {
      $self->save_error("Invalid size for --$opt->{long}");
   }
   return;
}

sub _parse_attribs {
   my ( $self, $option, $attribs ) = @_;
   my $types = $self->{types};
   return $option
      . ($attribs->{'short form'} ? '|' . $attribs->{'short form'}   : '' )
      . ($attribs->{'negatable'}  ? '!'                              : '' )
      . ($attribs->{'cumulative'} ? '+'                              : '' )
      . ($attribs->{'type'}       ? '=' . $types->{$attribs->{type}} : '' );
}

sub _parse_synopsis {
   my ( $self, $file ) = @_;
   $file ||= $self->{file} || __FILE__;
   MKDEBUG && _d("Parsing SYNOPSIS in", $file);

   local $INPUT_RECORD_SEPARATOR = '';  # read paragraphs
   open my $fh, "<", $file or die "Cannot open $file: $OS_ERROR";
   my $para;
   1 while defined($para = <$fh>) && $para !~ m/^=head1 SYNOPSIS/;
   die "$file does not contain a SYNOPSIS section" unless $para;
   my @synop;
   for ( 1..2 ) {  # 1 for the usage, 2 for the description
      my $para = <$fh>;
      push @synop, $para;
   }
   close $fh;
   MKDEBUG && _d("Raw SYNOPSIS text:", @synop);
   my ($usage, $desc) = @synop;
   die "The SYNOPSIS section in $file is not formatted properly"
      unless $usage && $desc;

   $usage =~ s/^\s*Usage:\s+(.+)/$1/;
   chomp $usage;

   $desc =~ s/\n/ /g;
   $desc =~ s/\s{2,}/ /g;
   $desc =~ s/\. ([A-Z][a-z])/.  $1/g;
   $desc =~ s/\s+$//;

   return (
      description => $desc,
      usage       => $usage,
   );
};

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;

# ###########################################################################
# End OptionParser package
# ###########################################################################

# ###########################################################################
# VersionParser package 6667
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the SVN repository at,
#   trunk/common/VersionParser.pm
#   trunk/common/t/VersionParser.t
# See http://code.google.com/p/maatkit/wiki/Developers for more information.
# ###########################################################################
package VersionParser;

use strict;
use warnings FATAL => 'all';

use English qw(-no_match_vars);

use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class ) = @_;
   bless {}, $class;
}

sub parse {
   my ( $self, $str ) = @_;
   my $result = sprintf('%03d%03d%03d', $str =~ m/(\d+)/g);
   MKDEBUG && _d($str, 'parses to', $result);
   return $result;
}

sub version_ge {
   my ( $self, $dbh, $target ) = @_;
   if ( !$self->{$dbh} ) {
      $self->{$dbh} = $self->parse(
         $dbh->selectrow_array('SELECT VERSION()'));
   }
   my $result = $self->{$dbh} ge $self->parse($target) ? 1 : 0;
   MKDEBUG && _d($self->{$dbh}, 'ge', $target, ':', $result);
   return $result;
}

sub innodb_version {
   my ( $self, $dbh ) = @_;
   return unless $dbh;
   my $innodb_version = "NO";

   my ($innodb) =
      grep { $_->{engine} =~ m/InnoDB/i }
      map  {
         my %hash;
         @hash{ map { lc $_ } keys %$_ } = values %$_;
         \%hash;
      }
      @{ $dbh->selectall_arrayref("SHOW ENGINES", {Slice=>{}}) };
   if ( $innodb ) {
      MKDEBUG && _d("InnoDB support:", $innodb->{support});
      if ( $innodb->{support} =~ m/YES|DEFAULT/i ) {
         my $vars = $dbh->selectrow_hashref(
            "SHOW VARIABLES LIKE 'innodb_version'");
         $innodb_version = !$vars ? "BUILTIN"
                         :          ($vars->{Value} || $vars->{value});
      }
      else {
         $innodb_version = $innodb->{support};  # probably DISABLED or NO
      }
   }

   MKDEBUG && _d("InnoDB version:", $innodb_version);
   return $innodb_version;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;

# ###########################################################################
# End VersionParser package
# ###########################################################################

# ###########################################################################
# DSNParser package 7388
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the SVN repository at,
#   trunk/common/DSNParser.pm
#   trunk/common/t/DSNParser.t
# See http://code.google.com/p/maatkit/wiki/Developers for more information.
# ###########################################################################

package DSNParser;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use Data::Dumper;
$Data::Dumper::Indent    = 0;
$Data::Dumper::Quotekeys = 0;

eval {
   require DBI;
};
my $have_dbi = $EVAL_ERROR ? 0 : 1;


sub new {
   my ( $class, %args ) = @_;
   foreach my $arg ( qw(opts) ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my $self = {
      opts => {}  # h, P, u, etc.  Should come from DSN OPTIONS section in POD.
   };
   foreach my $opt ( @{$args{opts}} ) {
      if ( !$opt->{key} || !$opt->{desc} ) {
         die "Invalid DSN option: ", Dumper($opt);
      }
      MKDEBUG && _d('DSN option:',
         join(', ',
            map { "$_=" . (defined $opt->{$_} ? ($opt->{$_} || '') : 'undef') }
               keys %$opt
         )
      );
      $self->{opts}->{$opt->{key}} = {
         dsn  => $opt->{dsn},
         desc => $opt->{desc},
         copy => $opt->{copy} || 0,
      };
   }
   return bless $self, $class;
}

sub prop {
   my ( $self, $prop, $value ) = @_;
   if ( @_ > 2 ) {
      MKDEBUG && _d('Setting', $prop, 'property');
      $self->{$prop} = $value;
   }
   return $self->{$prop};
}

sub parse {
   my ( $self, $dsn, $prev, $defaults ) = @_;
   if ( !$dsn ) {
      MKDEBUG && _d('No DSN to parse');
      return;
   }
   MKDEBUG && _d('Parsing', $dsn);
   $prev     ||= {};
   $defaults ||= {};
   my %given_props;
   my %final_props;
   my $opts = $self->{opts};

   foreach my $dsn_part ( split(/,/, $dsn) ) {
      if ( my ($prop_key, $prop_val) = $dsn_part =~  m/^(.)=(.*)$/ ) {
         $given_props{$prop_key} = $prop_val;
      }
      else {
         MKDEBUG && _d('Interpreting', $dsn_part, 'as h=', $dsn_part);
         $given_props{h} = $dsn_part;
      }
   }

   foreach my $key ( keys %$opts ) {
      MKDEBUG && _d('Finding value for', $key);
      $final_props{$key} = $given_props{$key};
      if (   !defined $final_props{$key}
           && defined $prev->{$key} && $opts->{$key}->{copy} )
      {
         $final_props{$key} = $prev->{$key};
         MKDEBUG && _d('Copying value for', $key, 'from previous DSN');
      }
      if ( !defined $final_props{$key} ) {
         $final_props{$key} = $defaults->{$key};
         MKDEBUG && _d('Copying value for', $key, 'from defaults');
      }
   }

   foreach my $key ( keys %given_props ) {
      die "Unknown DSN option '$key' in '$dsn'.  For more details, "
            . "please use the --help option, or try 'perldoc $PROGRAM_NAME' "
            . "for complete documentation."
         unless exists $opts->{$key};
   }
   if ( (my $required = $self->prop('required')) ) {
      foreach my $key ( keys %$required ) {
         die "Missing required DSN option '$key' in '$dsn'.  For more details, "
               . "please use the --help option, or try 'perldoc $PROGRAM_NAME' "
               . "for complete documentation."
            unless $final_props{$key};
      }
   }

   return \%final_props;
}

sub parse_options {
   my ( $self, $o ) = @_;
   die 'I need an OptionParser object' unless ref $o eq 'OptionParser';
   my $dsn_string
      = join(',',
          map  { "$_=".$o->get($_); }
          grep { $o->has($_) && $o->get($_) }
          keys %{$self->{opts}}
        );
   MKDEBUG && _d('DSN string made from options:', $dsn_string);
   return $self->parse($dsn_string);
}

sub as_string {
   my ( $self, $dsn, $props ) = @_;
   return $dsn unless ref $dsn;
   my %allowed = $props ? map { $_=>1 } @$props : ();
   return join(',',
      map  { "$_=" . ($_ eq 'p' ? '...' : $dsn->{$_})  }
      grep { defined $dsn->{$_} && $self->{opts}->{$_} }
      grep { !$props || $allowed{$_}                   }
      sort keys %$dsn );
}

sub usage {
   my ( $self ) = @_;
   my $usage
      = "DSN syntax is key=value[,key=value...]  Allowable DSN keys:\n\n"
      . "  KEY  COPY  MEANING\n"
      . "  ===  ====  =============================================\n";
   my %opts = %{$self->{opts}};
   foreach my $key ( sort keys %opts ) {
      $usage .= "  $key    "
             .  ($opts{$key}->{copy} ? 'yes   ' : 'no    ')
             .  ($opts{$key}->{desc} || '[No description]')
             . "\n";
   }
   $usage .= "\n  If the DSN is a bareword, the word is treated as the 'h' key.\n";
   return $usage;
}

sub get_cxn_params {
   my ( $self, $info ) = @_;
   my $dsn;
   my %opts = %{$self->{opts}};
   my $driver = $self->prop('dbidriver') || '';
   if ( $driver eq 'Pg' ) {
      $dsn = 'DBI:Pg:dbname=' . ( $info->{D} || '' ) . ';'
         . join(';', map  { "$opts{$_}->{dsn}=$info->{$_}" }
                     grep { defined $info->{$_} }
                     qw(h P));
   }
   else {
      $dsn = 'DBI:mysql:' . ( $info->{D} || '' ) . ';'
         . join(';', map  { "$opts{$_}->{dsn}=$info->{$_}" }
                     grep { defined $info->{$_} }
                     qw(F h P S A))
         . ';mysql_read_default_group=client';
   }
   MKDEBUG && _d($dsn);
   return ($dsn, $info->{u}, $info->{p});
}

sub fill_in_dsn {
   my ( $self, $dbh, $dsn ) = @_;
   my $vars = $dbh->selectall_hashref('SHOW VARIABLES', 'Variable_name');
   my ($user, $db) = $dbh->selectrow_array('SELECT USER(), DATABASE()');
   $user =~ s/@.*//;
   $dsn->{h} ||= $vars->{hostname}->{Value};
   $dsn->{S} ||= $vars->{'socket'}->{Value};
   $dsn->{P} ||= $vars->{port}->{Value};
   $dsn->{u} ||= $user;
   $dsn->{D} ||= $db;
}

sub get_dbh {
   my ( $self, $cxn_string, $user, $pass, $opts ) = @_;
   $opts ||= {};
   my $defaults = {
      AutoCommit         => 0,
      RaiseError         => 1,
      PrintError         => 0,
      ShowErrorStatement => 1,
      mysql_enable_utf8 => ($cxn_string =~ m/charset=utf8/i ? 1 : 0),
   };
   @{$defaults}{ keys %$opts } = values %$opts;

   if ( $opts->{mysql_use_result} ) {
      $defaults->{mysql_use_result} = 1;
   }

   if ( !$have_dbi ) {
      die "Cannot connect to MySQL because the Perl DBI module is not "
         . "installed or not found.  Run 'perl -MDBI' to see the directories "
         . "that Perl searches for DBI.  If DBI is not installed, try:\n"
         . "  Debian/Ubuntu  apt-get install libdbi-perl\n"
         . "  RHEL/CentOS    yum install perl-DBI\n"
         . "  OpenSolaris    pgk install pkg:/SUNWpmdbi\n";

   }

   my $dbh;
   my $tries = 2;
   while ( !$dbh && $tries-- ) {
      MKDEBUG && _d($cxn_string, ' ', $user, ' ', $pass, ' {',
         join(', ', map { "$_=>$defaults->{$_}" } keys %$defaults ), '}');

      eval {
         $dbh = DBI->connect($cxn_string, $user, $pass, $defaults);

         if ( $cxn_string =~ m/mysql/i ) {
            my $sql;

            $sql = 'SELECT @@SQL_MODE';
            MKDEBUG && _d($dbh, $sql);
            my ($sql_mode) = $dbh->selectrow_array($sql);

            $sql = 'SET @@SQL_QUOTE_SHOW_CREATE = 1'
                 . '/*!40101, @@SQL_MODE=\'NO_AUTO_VALUE_ON_ZERO'
                 . ($sql_mode ? ",$sql_mode" : '')
                 . '\'*/';
            MKDEBUG && _d($dbh, $sql);
            $dbh->do($sql);

            if ( my ($charset) = $cxn_string =~ m/charset=(\w+)/ ) {
               $sql = "/*!40101 SET NAMES $charset*/";
               MKDEBUG && _d($dbh, ':', $sql);
               $dbh->do($sql);
               MKDEBUG && _d('Enabling charset for STDOUT');
               if ( $charset eq 'utf8' ) {
                  binmode(STDOUT, ':utf8')
                     or die "Can't binmode(STDOUT, ':utf8'): $OS_ERROR";
               }
               else {
                  binmode(STDOUT) or die "Can't binmode(STDOUT): $OS_ERROR";
               }
            }

            if ( $self->prop('set-vars') ) {
               $sql = "SET " . $self->prop('set-vars');
               MKDEBUG && _d($dbh, ':', $sql);
               $dbh->do($sql);
            }
         }
      };
      if ( !$dbh && $EVAL_ERROR ) {
         MKDEBUG && _d($EVAL_ERROR);
         if ( $EVAL_ERROR =~ m/not a compiled character set|character set utf8/ ) {
            MKDEBUG && _d('Going to try again without utf8 support');
            delete $defaults->{mysql_enable_utf8};
         }
         elsif ( $EVAL_ERROR =~ m/locate DBD\/mysql/i ) {
            die "Cannot connect to MySQL because the Perl DBD::mysql module is "
               . "not installed or not found.  Run 'perl -MDBD::mysql' to see "
               . "the directories that Perl searches for DBD::mysql.  If "
               . "DBD::mysql is not installed, try:\n"
               . "  Debian/Ubuntu  apt-get install libdbd-mysql-perl\n"
               . "  RHEL/CentOS    yum install perl-DBD-MySQL\n"
               . "  OpenSolaris    pgk install pkg:/SUNWapu13dbd-mysql\n";
         }
         if ( !$tries ) {
            die $EVAL_ERROR;
         }
      }
   }

   MKDEBUG && _d('DBH info: ',
      $dbh,
      Dumper($dbh->selectrow_hashref(
         'SELECT DATABASE(), CONNECTION_ID(), VERSION()/*!50038 , @@hostname*/')),
      'Connection info:',      $dbh->{mysql_hostinfo},
      'Character set info:',   Dumper($dbh->selectall_arrayref(
                     'SHOW VARIABLES LIKE "character_set%"', { Slice => {}})),
      '$DBD::mysql::VERSION:', $DBD::mysql::VERSION,
      '$DBI::VERSION:',        $DBI::VERSION,
   );

   return $dbh;
}

sub get_hostname {
   my ( $self, $dbh ) = @_;
   if ( my ($host) = ($dbh->{mysql_hostinfo} || '') =~ m/^(\w+) via/ ) {
      return $host;
   }
   my ( $hostname, $one ) = $dbh->selectrow_array(
      'SELECT /*!50038 @@hostname, */ 1');
   return $hostname;
}

sub disconnect {
   my ( $self, $dbh ) = @_;
   MKDEBUG && $self->print_active_handles($dbh);
   $dbh->disconnect;
}

sub print_active_handles {
   my ( $self, $thing, $level ) = @_;
   $level ||= 0;
   printf("# Active %sh: %s %s %s\n", ($thing->{Type} || 'undef'), "\t" x $level,
      $thing, (($thing->{Type} || '') eq 'st' ? $thing->{Statement} || '' : ''))
      or die "Cannot print: $OS_ERROR";
   foreach my $handle ( grep {defined} @{ $thing->{ChildHandles} } ) {
      $self->print_active_handles( $handle, $level + 1 );
   }
}

sub copy {
   my ( $self, $dsn_1, $dsn_2, %args ) = @_;
   die 'I need a dsn_1 argument' unless $dsn_1;
   die 'I need a dsn_2 argument' unless $dsn_2;
   my %new_dsn = map {
      my $key = $_;
      my $val;
      if ( $args{overwrite} ) {
         $val = defined $dsn_1->{$key} ? $dsn_1->{$key} : $dsn_2->{$key};
      }
      else {
         $val = defined $dsn_2->{$key} ? $dsn_2->{$key} : $dsn_1->{$key};
      }
      $key => $val;
   } keys %{$self->{opts}};
   return \%new_dsn;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;

# ###########################################################################
# End DSNParser package
# ###########################################################################

# ###########################################################################
# MasterSlave package 7525
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the SVN repository at,
#   trunk/common/MasterSlave.pm
#   trunk/common/t/MasterSlave.t
# See http://code.google.com/p/maatkit/wiki/Developers for more information.
# ###########################################################################

package MasterSlave;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use List::Util qw(min max);
use Data::Dumper;
$Data::Dumper::Quotekeys = 0;
$Data::Dumper::Indent    = 0;

sub new {
   my ( $class, %args ) = @_;
   my $self = {
      %args,
      replication_thread => {},
   };
   return bless $self, $class;
}

sub recurse_to_slaves {
   my ( $self, $args, $level ) = @_;
   $level ||= 0;
   my $dp   = $args->{dsn_parser};
   my $dsn  = $args->{dsn};

   my $dbh;
   eval {
      $dbh = $args->{dbh} || $dp->get_dbh(
         $dp->get_cxn_params($dsn), { AutoCommit => 1 });
      MKDEBUG && _d('Connected to', $dp->as_string($dsn));
   };
   if ( $EVAL_ERROR ) {
      print STDERR "Cannot connect to ", $dp->as_string($dsn), "\n"
         or die "Cannot print: $OS_ERROR";
      return;
   }

   my $sql  = 'SELECT @@SERVER_ID';
   MKDEBUG && _d($sql);
   my ($id) = $dbh->selectrow_array($sql);
   MKDEBUG && _d('Working on server ID', $id);
   my $master_thinks_i_am = $dsn->{server_id};
   if ( !defined $id
       || ( defined $master_thinks_i_am && $master_thinks_i_am != $id )
       || $args->{server_ids_seen}->{$id}++
   ) {
      MKDEBUG && _d('Server ID seen, or not what master said');
      if ( $args->{skip_callback} ) {
         $args->{skip_callback}->($dsn, $dbh, $level, $args->{parent});
      }
      return;
   }

   $args->{callback}->($dsn, $dbh, $level, $args->{parent});

   if ( !defined $args->{recurse} || $level < $args->{recurse} ) {

      my @slaves =
         grep { !$_->{master_id} || $_->{master_id} == $id } # Only my slaves.
         $self->find_slave_hosts($dp, $dbh, $dsn, $args->{method});

      foreach my $slave ( @slaves ) {
         MKDEBUG && _d('Recursing from',
            $dp->as_string($dsn), 'to', $dp->as_string($slave));
         $self->recurse_to_slaves(
            { %$args, dsn => $slave, dbh => undef, parent => $dsn }, $level + 1 );
      }
   }
}

sub find_slave_hosts {
   my ( $self, $dsn_parser, $dbh, $dsn, $method ) = @_;

   my @methods = qw(processlist hosts);
   if ( $method ) {
      @methods = grep { $_ ne $method } @methods;
      unshift @methods, $method;
   }
   else {
      if ( ($dsn->{P} || 3306) != 3306 ) {
         MKDEBUG && _d('Port number is non-standard; using only hosts method');
         @methods = qw(hosts);
      }
   }
   MKDEBUG && _d('Looking for slaves on', $dsn_parser->as_string($dsn),
      'using methods', @methods);

   my @slaves;
   METHOD:
   foreach my $method ( @methods ) {
      my $find_slaves = "_find_slaves_by_$method";
      MKDEBUG && _d('Finding slaves with', $find_slaves);
      @slaves = $self->$find_slaves($dsn_parser, $dbh, $dsn);
      last METHOD if @slaves;
   }

   MKDEBUG && _d('Found', scalar(@slaves), 'slaves');
   return @slaves;
}

sub _find_slaves_by_processlist {
   my ( $self, $dsn_parser, $dbh, $dsn ) = @_;

   my @slaves = map  {
      my $slave        = $dsn_parser->parse("h=$_", $dsn);
      $slave->{source} = 'processlist';
      $slave;
   }
   grep { $_ }
   map  {
      my ( $host ) = $_->{host} =~ m/^([^:]+):/;
      if ( $host eq 'localhost' ) {
         $host = '127.0.0.1'; # Replication never uses sockets.
      }
      $host;
   } $self->get_connected_slaves($dbh);

   return @slaves;
}

sub _find_slaves_by_hosts {
   my ( $self, $dsn_parser, $dbh, $dsn ) = @_;

   my @slaves;
   my $sql = 'SHOW SLAVE HOSTS';
   MKDEBUG && _d($dbh, $sql);
   @slaves = @{$dbh->selectall_arrayref($sql, { Slice => {} })};

   if ( @slaves ) {
      MKDEBUG && _d('Found some SHOW SLAVE HOSTS info');
      @slaves = map {
         my %hash;
         @hash{ map { lc $_ } keys %$_ } = values %$_;
         my $spec = "h=$hash{host},P=$hash{port}"
            . ( $hash{user} ? ",u=$hash{user}" : '')
            . ( $hash{password} ? ",p=$hash{password}" : '');
         my $dsn           = $dsn_parser->parse($spec, $dsn);
         $dsn->{server_id} = $hash{server_id};
         $dsn->{master_id} = $hash{master_id};
         $dsn->{source}    = 'hosts';
         $dsn;
      } @slaves;
   }

   return @slaves;
}

sub get_connected_slaves {
   my ( $self, $dbh ) = @_;

   my $show = "SHOW GRANTS FOR ";
   my $user = 'CURRENT_USER()';
   my $vp   = $self->{VersionParser};
   if ( $vp && !$vp->version_ge($dbh, '4.1.2') ) {
      $user = $dbh->selectrow_arrayref('SELECT USER()')->[0];
      $user =~ s/([^@]+)@(.+)/'$1'\@'$2'/;
   }
   my $sql = $show . $user;
   MKDEBUG && _d($dbh, $sql);

   my $proc;
   eval {
      $proc = grep {
         m/ALL PRIVILEGES.*?\*\.\*|PROCESS/
      } @{$dbh->selectcol_arrayref($sql)};
   };
   if ( $EVAL_ERROR ) {

      if ( $EVAL_ERROR =~ m/no such grant defined for user/ ) {
         MKDEBUG && _d('Retrying SHOW GRANTS without host; error:',
            $EVAL_ERROR);
         ($user) = split('@', $user);
         $sql    = $show . $user;
         MKDEBUG && _d($sql);
         eval {
            $proc = grep {
               m/ALL PRIVILEGES.*?\*\.\*|PROCESS/
            } @{$dbh->selectcol_arrayref($sql)};
         };
      }

      die "Failed to $sql: $EVAL_ERROR" if $EVAL_ERROR;
   }
   if ( !$proc ) {
      die "You do not have the PROCESS privilege";
   }

   $sql = 'SHOW PROCESSLIST';
   MKDEBUG && _d($dbh, $sql);
   grep { $_->{command} =~ m/Binlog Dump/i }
   map  { # Lowercase the column names
      my %hash;
      @hash{ map { lc $_ } keys %$_ } = values %$_;
      \%hash;
   }
   @{$dbh->selectall_arrayref($sql, { Slice => {} })};
}

sub is_master_of {
   my ( $self, $master, $slave ) = @_;
   my $master_status = $self->get_master_status($master)
      or die "The server specified as a master is not a master";
   my $slave_status  = $self->get_slave_status($slave)
      or die "The server specified as a slave is not a slave";
   my @connected     = $self->get_connected_slaves($master)
      or die "The server specified as a master has no connected slaves";
   my (undef, $port) = $master->selectrow_array('SHOW VARIABLES LIKE "port"');

   if ( $port != $slave_status->{master_port} ) {
      die "The slave is connected to $slave_status->{master_port} "
         . "but the master's port is $port";
   }

   if ( !grep { $slave_status->{master_user} eq $_->{user} } @connected ) {
      die "I don't see any slave I/O thread connected with user "
         . $slave_status->{master_user};
   }

   if ( ($slave_status->{slave_io_state} || '')
      eq 'Waiting for master to send event' )
   {
      my ( $master_log_name, $master_log_num )
         = $master_status->{file} =~ m/^(.*?)\.0*([1-9][0-9]*)$/;
      my ( $slave_log_name, $slave_log_num )
         = $slave_status->{master_log_file} =~ m/^(.*?)\.0*([1-9][0-9]*)$/;
      if ( $master_log_name ne $slave_log_name
         || abs($master_log_num - $slave_log_num) > 1 )
      {
         die "The slave thinks it is reading from "
            . "$slave_status->{master_log_file},  but the "
            . "master is writing to $master_status->{file}";
      }
   }
   return 1;
}

sub get_master_dsn {
   my ( $self, $dbh, $dsn, $dsn_parser ) = @_;
   my $master = $self->get_slave_status($dbh) or return undef;
   my $spec   = "h=$master->{master_host},P=$master->{master_port}";
   return       $dsn_parser->parse($spec, $dsn);
}

sub get_slave_status {
   my ( $self, $dbh ) = @_;
   if ( !$self->{not_a_slave}->{$dbh} ) {
      my $sth = $self->{sths}->{$dbh}->{SLAVE_STATUS}
            ||= $dbh->prepare('SHOW SLAVE STATUS');
      MKDEBUG && _d($dbh, 'SHOW SLAVE STATUS');
      $sth->execute();
      my ($ss) = @{$sth->fetchall_arrayref({})};

      if ( $ss && %$ss ) {
         $ss = { map { lc($_) => $ss->{$_} } keys %$ss }; # lowercase the keys
         return $ss;
      }

      MKDEBUG && _d('This server returns nothing for SHOW SLAVE STATUS');
      $self->{not_a_slave}->{$dbh}++;
   }
}

sub get_master_status {
   my ( $self, $dbh ) = @_;

   if ( $self->{not_a_master}->{$dbh} ) {
      MKDEBUG && _d('Server on dbh', $dbh, 'is not a master');
      return;
   }

   my $sth = $self->{sths}->{$dbh}->{MASTER_STATUS}
         ||= $dbh->prepare('SHOW MASTER STATUS');
   MKDEBUG && _d($dbh, 'SHOW MASTER STATUS');
   $sth->execute();
   my ($ms) = @{$sth->fetchall_arrayref({})};
   MKDEBUG && _d(Dumper($ms));

   if ( !$ms || scalar keys %$ms < 2 ) {
      MKDEBUG && _d('Server on dbh', $dbh, 'does not seem to be a master');
      $self->{not_a_master}->{$dbh}++;
   }

  return { map { lc($_) => $ms->{$_} } keys %$ms }; # lowercase the keys
}

sub wait_for_master {
   my ( $self, %args ) = @_;
   my @required_args = qw(master_status slave_dbh);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($master_status, $slave_dbh) = @args{@required_args};
   my $timeout       = $args{timeout} || 60;

   my $result;
   my $waited;
   if ( $master_status ) {
      my $sql = "SELECT MASTER_POS_WAIT('$master_status->{file}', "
              . "$master_status->{position}, $timeout)";
      MKDEBUG && _d($slave_dbh, $sql);
      my $start = time;
      ($result) = $slave_dbh->selectrow_array($sql);

      $waited = time - $start;

      MKDEBUG && _d('Result of waiting:', $result);
      MKDEBUG && _d("Waited", $waited, "seconds");
   }
   else {
      MKDEBUG && _d('Not waiting: this server is not a master');
   }

   return {
      result => $result,
      waited => $waited,
   };
}

sub stop_slave {
   my ( $self, $dbh ) = @_;
   my $sth = $self->{sths}->{$dbh}->{STOP_SLAVE}
         ||= $dbh->prepare('STOP SLAVE');
   MKDEBUG && _d($dbh, $sth->{Statement});
   $sth->execute();
}

sub start_slave {
   my ( $self, $dbh, $pos ) = @_;
   if ( $pos ) {
      my $sql = "START SLAVE UNTIL MASTER_LOG_FILE='$pos->{file}', "
              . "MASTER_LOG_POS=$pos->{position}";
      MKDEBUG && _d($dbh, $sql);
      $dbh->do($sql);
   }
   else {
      my $sth = $self->{sths}->{$dbh}->{START_SLAVE}
            ||= $dbh->prepare('START SLAVE');
      MKDEBUG && _d($dbh, $sth->{Statement});
      $sth->execute();
   }
}

sub catchup_to_master {
   my ( $self, $slave, $master, $timeout ) = @_;
   $self->stop_slave($master);
   $self->stop_slave($slave);
   my $slave_status  = $self->get_slave_status($slave);
   my $slave_pos     = $self->repl_posn($slave_status);
   my $master_status = $self->get_master_status($master);
   my $master_pos    = $self->repl_posn($master_status);
   MKDEBUG && _d('Master position:', $self->pos_to_string($master_pos),
      'Slave position:', $self->pos_to_string($slave_pos));

   my $result;
   if ( $self->pos_cmp($slave_pos, $master_pos) < 0 ) {
      MKDEBUG && _d('Waiting for slave to catch up to master');
      $self->start_slave($slave, $master_pos);

      $result = $self->wait_for_master(
            master_status => $master_status,
            slave_dbh     => $slave,
            timeout       => $timeout,
            master_status => $master_status
      );
      if ( !defined $result->{result} ) {
         $slave_status = $self->get_slave_status($slave);
         if ( !$self->slave_is_running($slave_status) ) {
            MKDEBUG && _d('Master position:',
               $self->pos_to_string($master_pos),
               'Slave position:', $self->pos_to_string($slave_pos));
            $slave_pos = $self->repl_posn($slave_status);
            if ( $self->pos_cmp($slave_pos, $master_pos) != 0 ) {
               die "MASTER_POS_WAIT() returned NULL but slave has not "
                  . "caught up to master";
            }
            MKDEBUG && _d('Slave is caught up to master and stopped');
         }
         else {
            die "Slave has not caught up to master and it is still running";
         }
      }
   }
   else {
      MKDEBUG && _d("Slave is already caught up to master");
   }

   return $result;
}

sub catchup_to_same_pos {
   my ( $self, $s1_dbh, $s2_dbh ) = @_;
   $self->stop_slave($s1_dbh);
   $self->stop_slave($s2_dbh);
   my $s1_status = $self->get_slave_status($s1_dbh);
   my $s2_status = $self->get_slave_status($s2_dbh);
   my $s1_pos    = $self->repl_posn($s1_status);
   my $s2_pos    = $self->repl_posn($s2_status);
   if ( $self->pos_cmp($s1_pos, $s2_pos) < 0 ) {
      $self->start_slave($s1_dbh, $s2_pos);
   }
   elsif ( $self->pos_cmp($s2_pos, $s1_pos) < 0 ) {
      $self->start_slave($s2_dbh, $s1_pos);
   }

   $s1_status = $self->get_slave_status($s1_dbh);
   $s2_status = $self->get_slave_status($s2_dbh);
   $s1_pos    = $self->repl_posn($s1_status);
   $s2_pos    = $self->repl_posn($s2_status);

   if ( $self->slave_is_running($s1_status)
     || $self->slave_is_running($s2_status)
     || $self->pos_cmp($s1_pos, $s2_pos) != 0)
   {
      die "The servers aren't both stopped at the same position";
   }

}

sub change_master_to {
   my ( $self, $dbh, $master_dsn, $master_pos ) = @_;
   $self->stop_slave($dbh);
   MKDEBUG && _d(Dumper($master_dsn), Dumper($master_pos));
   my $sql = "CHANGE MASTER TO MASTER_HOST='$master_dsn->{h}', "
      . "MASTER_PORT= $master_dsn->{P}, MASTER_LOG_FILE='$master_pos->{file}', "
      . "MASTER_LOG_POS=$master_pos->{position}";
   MKDEBUG && _d($dbh, $sql);
   $dbh->do($sql);
}

sub make_sibling_of_master {
   my ( $self, $slave_dbh, $slave_dsn, $dsn_parser, $timeout) = @_;

   my $master_dsn  = $self->get_master_dsn($slave_dbh, $slave_dsn, $dsn_parser)
      or die "This server is not a slave";
   my $master_dbh  = $dsn_parser->get_dbh(
      $dsn_parser->get_cxn_params($master_dsn), { AutoCommit => 1 });
   my $gmaster_dsn
      = $self->get_master_dsn($master_dbh, $master_dsn, $dsn_parser)
      or die "This server's master is not a slave";
   my $gmaster_dbh = $dsn_parser->get_dbh(
      $dsn_parser->get_cxn_params($gmaster_dsn), { AutoCommit => 1 });
   if ( $self->short_host($slave_dsn) eq $self->short_host($gmaster_dsn) ) {
      die "The slave's master's master is the slave: master-master replication";
   }

   $self->stop_slave($master_dbh);
   $self->catchup_to_master($slave_dbh, $master_dbh, $timeout);
   $self->stop_slave($slave_dbh);

   my $master_status = $self->get_master_status($master_dbh);
   my $mslave_status = $self->get_slave_status($master_dbh);
   my $slave_status  = $self->get_slave_status($slave_dbh);
   my $master_pos    = $self->repl_posn($master_status);
   my $slave_pos     = $self->repl_posn($slave_status);

   if ( !$self->slave_is_running($mslave_status)
     && !$self->slave_is_running($slave_status)
     && $self->pos_cmp($master_pos, $slave_pos) == 0)
   {
      $self->change_master_to($slave_dbh, $gmaster_dsn,
         $self->repl_posn($mslave_status)); # Note it's not $master_pos!
   }
   else {
      die "The servers aren't both stopped at the same position";
   }

   $mslave_status = $self->get_slave_status($master_dbh);
   $slave_status  = $self->get_slave_status($slave_dbh);
   my $mslave_pos = $self->repl_posn($mslave_status);
   $slave_pos     = $self->repl_posn($slave_status);
   if ( $self->short_host($mslave_status) ne $self->short_host($slave_status)
     || $self->pos_cmp($mslave_pos, $slave_pos) != 0)
   {
      die "The servers don't have the same master/position after the change";
   }
}

sub make_slave_of_sibling {
   my ( $self, $slave_dbh, $slave_dsn, $sib_dbh, $sib_dsn,
        $dsn_parser, $timeout) = @_;

   if ( $self->short_host($slave_dsn) eq $self->short_host($sib_dsn) ) {
      die "You are trying to make the slave a slave of itself";
   }

   my $master_dsn1 = $self->get_master_dsn($slave_dbh, $slave_dsn, $dsn_parser)
      or die "This server is not a slave";
   my $master_dbh1 = $dsn_parser->get_dbh(
      $dsn_parser->get_cxn_params($master_dsn1), { AutoCommit => 1 });
   my $master_dsn2 = $self->get_master_dsn($slave_dbh, $slave_dsn, $dsn_parser)
      or die "The sibling is not a slave";
   if ( $self->short_host($master_dsn1) ne $self->short_host($master_dsn2) ) {
      die "This server isn't a sibling of the slave";
   }
   my $sib_master_stat = $self->get_master_status($sib_dbh)
      or die "Binary logging is not enabled on the sibling";
   die "The log_slave_updates option is not enabled on the sibling"
      unless $self->has_slave_updates($sib_dbh);

   $self->catchup_to_same_pos($slave_dbh, $sib_dbh);

   $sib_master_stat = $self->get_master_status($sib_dbh);
   $self->change_master_to($slave_dbh, $sib_dsn,
         $self->repl_posn($sib_master_stat));

   my $slave_status = $self->get_slave_status($slave_dbh);
   my $slave_pos    = $self->repl_posn($slave_status);
   $sib_master_stat = $self->get_master_status($sib_dbh);
   if ( $self->short_host($slave_status) ne $self->short_host($sib_dsn)
     || $self->pos_cmp($self->repl_posn($sib_master_stat), $slave_pos) != 0)
   {
      die "After changing the slave's master, it isn't a slave of the sibling, "
         . "or it has a different replication position than the sibling";
   }
}

sub make_slave_of_uncle {
   my ( $self, $slave_dbh, $slave_dsn, $unc_dbh, $unc_dsn,
        $dsn_parser, $timeout) = @_;

   if ( $self->short_host($slave_dsn) eq $self->short_host($unc_dsn) ) {
      die "You are trying to make the slave a slave of itself";
   }

   my $master_dsn = $self->get_master_dsn($slave_dbh, $slave_dsn, $dsn_parser)
      or die "This server is not a slave";
   my $master_dbh = $dsn_parser->get_dbh(
      $dsn_parser->get_cxn_params($master_dsn), { AutoCommit => 1 });
   my $gmaster_dsn
      = $self->get_master_dsn($master_dbh, $master_dsn, $dsn_parser)
      or die "The master is not a slave";
   my $unc_master_dsn
      = $self->get_master_dsn($unc_dbh, $unc_dsn, $dsn_parser)
      or die "The uncle is not a slave";
   if ($self->short_host($gmaster_dsn) ne $self->short_host($unc_master_dsn)) {
      die "The uncle isn't really the slave's uncle";
   }

   my $unc_master_stat = $self->get_master_status($unc_dbh)
      or die "Binary logging is not enabled on the uncle";
   die "The log_slave_updates option is not enabled on the uncle"
      unless $self->has_slave_updates($unc_dbh);

   $self->catchup_to_same_pos($master_dbh, $unc_dbh);
   $self->catchup_to_master($slave_dbh, $master_dbh, $timeout);

   my $slave_status  = $self->get_slave_status($slave_dbh);
   my $master_status = $self->get_master_status($master_dbh);
   if ( $self->pos_cmp(
         $self->repl_posn($slave_status),
         $self->repl_posn($master_status)) != 0 )
   {
      die "The slave is not caught up to its master";
   }

   $unc_master_stat = $self->get_master_status($unc_dbh);
   $self->change_master_to($slave_dbh, $unc_dsn,
      $self->repl_posn($unc_master_stat));


   $slave_status    = $self->get_slave_status($slave_dbh);
   my $slave_pos    = $self->repl_posn($slave_status);
   if ( $self->short_host($slave_status) ne $self->short_host($unc_dsn)
     || $self->pos_cmp($self->repl_posn($unc_master_stat), $slave_pos) != 0)
   {
      die "After changing the slave's master, it isn't a slave of the uncle, "
         . "or it has a different replication position than the uncle";
   }
}

sub detach_slave {
   my ( $self, $dbh ) = @_;
   $self->stop_slave($dbh);
   my $stat = $self->get_slave_status($dbh)
      or die "This server is not a slave";
   $dbh->do('CHANGE MASTER TO MASTER_HOST=""');
   $dbh->do('RESET SLAVE'); # Wipes out master.info, etc etc
   return $stat;
}

sub slave_is_running {
   my ( $self, $slave_status ) = @_;
   return ($slave_status->{slave_sql_running} || 'No') eq 'Yes';
}

sub has_slave_updates {
   my ( $self, $dbh ) = @_;
   my $sql = q{SHOW VARIABLES LIKE 'log_slave_updates'};
   MKDEBUG && _d($dbh, $sql);
   my ($name, $value) = $dbh->selectrow_array($sql);
   return $value && $value =~ m/^(1|ON)$/;
}

sub repl_posn {
   my ( $self, $status ) = @_;
   if ( exists $status->{file} && exists $status->{position} ) {
      return {
         file     => $status->{file},
         position => $status->{position},
      };
   }
   else {
      return {
         file     => $status->{relay_master_log_file},
         position => $status->{exec_master_log_pos},
      };
   }
}

sub get_slave_lag {
   my ( $self, $dbh ) = @_;
   my $stat = $self->get_slave_status($dbh);
   return $stat->{seconds_behind_master};
}

sub pos_cmp {
   my ( $self, $a, $b ) = @_;
   return $self->pos_to_string($a) cmp $self->pos_to_string($b);
}

sub short_host {
   my ( $self, $dsn ) = @_;
   my ($host, $port);
   if ( $dsn->{master_host} ) {
      $host = $dsn->{master_host};
      $port = $dsn->{master_port};
   }
   else {
      $host = $dsn->{h};
      $port = $dsn->{P};
   }
   return ($host || '[default]') . ( ($port || 3306) == 3306 ? '' : ":$port" );
}

sub is_replication_thread {
   my ( $self, $query, %args ) = @_; 
   return unless $query;

   my $type = lc $args{type} || 'all';
   die "Invalid type: $type"
      unless $type =~ m/^binlog_dump|slave_io|slave_sql|all$/i;

   my $match = 0;
   if ( $type =~ m/binlog_dump|all/i ) {
      $match = 1
         if ($query->{Command} || $query->{command} || '') eq "Binlog Dump";
   }
   if ( !$match ) {
      if ( ($query->{User} || $query->{user} || '') eq "system user" ) {
         MKDEBUG && _d("Slave replication thread");
         if ( $type ne 'all' ) { 
            my $state = $query->{State} || $query->{state} || '';

            if ( $state =~ m/^init|end$/ ) {
               MKDEBUG && _d("Special state:", $state);
               $match = 1;
            }
            else {
               my ($slave_sql) = $state =~ m/
                  ^(Waiting\sfor\sthe\snext\sevent
                   |Reading\sevent\sfrom\sthe\srelay\slog
                   |Has\sread\sall\srelay\slog;\swaiting
                   |Making\stemp\sfile
                   |Waiting\sfor\sslave\smutex\son\sexit)/xi; 

               $match = $type eq 'slave_sql' &&  $slave_sql ? 1
                      : $type eq 'slave_io'  && !$slave_sql ? 1
                      :                                       0;
            }
         }
         else {
            $match = 1;
         }
      }
      else {
         MKDEBUG && _d('Not system user');
      }

      if ( !defined $args{check_known_ids} || $args{check_known_ids} ) {
         my $id = $query->{Id} || $query->{id};
         if ( $match ) {
            $self->{replication_thread}->{$id} = 1;
         }
         else {
            if ( $self->{replication_thread}->{$id} ) {
               MKDEBUG && _d("Thread ID is a known replication thread ID");
               $match = 1;
            }
         }
      }
   }

   MKDEBUG && _d('Matches', $type, 'replication thread:',
      ($match ? 'yes' : 'no'), '; match:', $match);

   return $match;
}


sub get_replication_filters {
   my ( $self, %args ) = @_;
   my @required_args = qw(dbh);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh) = @args{@required_args};

   my %filters = ();

   my $status = $self->get_master_status($dbh);
   if ( $status ) {
      map { $filters{$_} = $status->{$_} }
      grep { defined $status->{$_} && $status->{$_} ne '' }
      qw(
         binlog_do_db
         binlog_ignore_db
      );
   }

   $status = $self->get_slave_status($dbh);
   if ( $status ) {
      map { $filters{$_} = $status->{$_} }
      grep { defined $status->{$_} && $status->{$_} ne '' }
      qw(
         replicate_do_db
         replicate_ignore_db
         replicate_do_table
         replicate_ignore_table 
         replicate_wild_do_table
         replicate_wild_ignore_table
      );

      my $sql = "SHOW VARIABLES LIKE 'slave_skip_errors'";
      MKDEBUG && _d($dbh, $sql);
      my $row = $dbh->selectrow_arrayref($sql);
      $filters{slave_skip_errors} = $row->[1] if $row->[1] && $row->[1] ne 'OFF';
   }

   return \%filters; 
}


sub pos_to_string {
   my ( $self, $pos ) = @_;
   my $fmt  = '%s/%020d';
   return sprintf($fmt, @{$pos}{qw(file position)});
}

sub reset_known_replication_threads {
   my ( $self ) = @_;
   $self->{replication_thread} = {};
   return;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;

# ###########################################################################
# End MasterSlave package
# ###########################################################################

# ###########################################################################
# Daemon package 6255
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the SVN repository at,
#   trunk/common/Daemon.pm
#   trunk/common/t/Daemon.t
# See http://code.google.com/p/maatkit/wiki/Developers for more information.
# ###########################################################################

package Daemon;

use strict;
use warnings FATAL => 'all';

use POSIX qw(setsid);
use English qw(-no_match_vars);

use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class, %args ) = @_;
   foreach my $arg ( qw(o) ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my $o = $args{o};
   my $self = {
      o        => $o,
      log_file => $o->has('log') ? $o->get('log') : undef,
      PID_file => $o->has('pid') ? $o->get('pid') : undef,
   };

   check_PID_file(undef, $self->{PID_file});

   MKDEBUG && _d('Daemonized child will log to', $self->{log_file});
   return bless $self, $class;
}

sub daemonize {
   my ( $self ) = @_;

   MKDEBUG && _d('About to fork and daemonize');
   defined (my $pid = fork()) or die "Cannot fork: $OS_ERROR";
   if ( $pid ) {
      MKDEBUG && _d('I am the parent and now I die');
      exit;
   }

   $self->{PID_owner} = $PID;
   $self->{child}     = 1;

   POSIX::setsid() or die "Cannot start a new session: $OS_ERROR";
   chdir '/'       or die "Cannot chdir to /: $OS_ERROR";

   $self->_make_PID_file();

   $OUTPUT_AUTOFLUSH = 1;

   if ( -t STDIN ) {
      close STDIN;
      open  STDIN, '/dev/null'
         or die "Cannot reopen STDIN to /dev/null: $OS_ERROR";
   }

   if ( $self->{log_file} ) {
      close STDOUT;
      open  STDOUT, '>>', $self->{log_file}
         or die "Cannot open log file $self->{log_file}: $OS_ERROR";

      close STDERR;
      open  STDERR, ">&STDOUT"
         or die "Cannot dupe STDERR to STDOUT: $OS_ERROR"; 
   }
   else {
      if ( -t STDOUT ) {
         close STDOUT;
         open  STDOUT, '>', '/dev/null'
            or die "Cannot reopen STDOUT to /dev/null: $OS_ERROR";
      }
      if ( -t STDERR ) {
         close STDERR;
         open  STDERR, '>', '/dev/null'
            or die "Cannot reopen STDERR to /dev/null: $OS_ERROR";
      }
   }

   MKDEBUG && _d('I am the child and now I live daemonized');
   return;
}

sub check_PID_file {
   my ( $self, $file ) = @_;
   my $PID_file = $self ? $self->{PID_file} : $file;
   MKDEBUG && _d('Checking PID file', $PID_file);
   if ( $PID_file && -f $PID_file ) {
      my $pid;
      eval { chomp($pid = `cat $PID_file`); };
      die "Cannot cat $PID_file: $OS_ERROR" if $EVAL_ERROR;
      MKDEBUG && _d('PID file exists; it contains PID', $pid);
      if ( $pid ) {
         my $pid_is_alive = kill 0, $pid;
         if ( $pid_is_alive ) {
            die "The PID file $PID_file already exists "
               . " and the PID that it contains, $pid, is running";
         }
         else {
            warn "Overwriting PID file $PID_file because the PID that it "
               . "contains, $pid, is not running";
         }
      }
      else {
         die "The PID file $PID_file already exists but it does not "
            . "contain a PID";
      }
   }
   else {
      MKDEBUG && _d('No PID file');
   }
   return;
}

sub make_PID_file {
   my ( $self ) = @_;
   if ( exists $self->{child} ) {
      die "Do not call Daemon::make_PID_file() for daemonized scripts";
   }
   $self->_make_PID_file();
   $self->{PID_owner} = $PID;
   return;
}

sub _make_PID_file {
   my ( $self ) = @_;

   my $PID_file = $self->{PID_file};
   if ( !$PID_file ) {
      MKDEBUG && _d('No PID file to create');
      return;
   }

   $self->check_PID_file();

   open my $PID_FH, '>', $PID_file
      or die "Cannot open PID file $PID_file: $OS_ERROR";
   print $PID_FH $PID
      or die "Cannot print to PID file $PID_file: $OS_ERROR";
   close $PID_FH
      or die "Cannot close PID file $PID_file: $OS_ERROR";

   MKDEBUG && _d('Created PID file:', $self->{PID_file});
   return;
}

sub _remove_PID_file {
   my ( $self ) = @_;
   if ( $self->{PID_file} && -f $self->{PID_file} ) {
      unlink $self->{PID_file}
         or warn "Cannot remove PID file $self->{PID_file}: $OS_ERROR";
      MKDEBUG && _d('Removed PID file');
   }
   else {
      MKDEBUG && _d('No PID to remove');
   }
   return;
}

sub DESTROY {
   my ( $self ) = @_;

   $self->_remove_PID_file() if ($self->{PID_owner} || 0) == $PID;

   return;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;

# ###########################################################################
# End Daemon package
# ###########################################################################

# ###########################################################################
# This is a combination of modules and programs in one -- a runnable module.
# http://www.perl.com/pub/a/2006/07/13/lightning-articles.html?page=last
# Or, look it up in the Camel book on pages 642 and 643 in the 3rd edition.
#
# Check at the end of this package for the call to main() which actually runs
# the program.
# ###########################################################################
package mk_slave_restart;

use English qw(-no_match_vars);
use IO::File;
use List::Util qw(min max);
use Time::HiRes qw(sleep);
use sigtrap qw(handler finish untrapped normal-signals);

use constant MKDEBUG => $ENV{MKDEBUG} || 0;

$OUTPUT_AUTOFLUSH = 1;

my $o;
my $dp;
my $q  = new Quoter();
my $vp = new VersionParser();
my %children;

sub main {
   @ARGV = @_;  # set global ARGV for this package

   # ########################################################################
   # Get configuration information.
   # ########################################################################
   $o  = new OptionParser();
   $o->get_specs();
   $o->get_opts();

   $dp = $o->DSNParser(); 
   $dp->prop('set-vars', $o->get('set-vars'));

   $o->set('verbose', 0) if $o->get('quiet');

   if ( !$o->get('help') ) {
      if ( $o->get('until-master') ) {
         if ( $o->get('until-master') !~ m/^[.\w-]+,\d+$/ ) {
            $o->save_error("Invalid --until-master argument, must be file,pos");
         }
      }
      if ( $o->get('until-relay') ) {
         if ( $o->get('until-relay') !~ m/^[.\w-]+,\d+$/ ) {
            $o->save_error("Invalid --until-relay argument, must be file,pos");
         }
      }
   }

   $o->usage_or_errors();

   # ########################################################################
   # First things first: if --stop was given, create the sentinel file.
   # ########################################################################
   my $sentinel = $o->get('sentinel');
   if ( $o->get('stop') ) {
      MKDEBUG && _d('Creating sentinel file', $sentinel);
      my $file = IO::File->new($sentinel, ">>")
         or die "Cannot open $sentinel: $OS_ERROR\n";
      print $file "Remove this file to permit mk-slave-restart to run\n"
         or die "Cannot write to $sentinel: $OS_ERROR\n";
      close $file
         or die "Cannot close $sentinel: $OS_ERROR\n";
      print STDOUT "Successfully created file $sentinel\n"
         unless $o->get('quiet');
      # Exit unlesss --monitor is given.
      if ( !$o->got('monitor') ) {
         MKDEBUG && _d('Nothing more to do, quitting');
         return 0;
      }
      else {
         # Wait for all other running instances to quit, assuming they have the
         # same --interval as this invocation.  Then remove the file and
         # continue.
         MKDEBUG && _d('Waiting for other instances to quit');
         sleep $o->get('max-sleep');
         MKDEBUG && _d('Unlinking', $sentinel);
         unlink $sentinel
            or die "Cannot unlink $sentinel: $OS_ERROR";
      }
   }

   # ########################################################################
   # Connect and go to work.
   # ########################################################################
   if ( $o->get('ask-pass') ) {
      $o->set('password', OptionParser::prompt_noecho("Enter password: "));
   }
   my $dsn_defaults = $dp->parse_options($o);
   my $dsn          = @ARGV ? $dp->parse(shift @ARGV, $dsn_defaults)
                    :         $dsn_defaults;
   my $dbh          = $dp->get_dbh($dp->get_cxn_params($dsn),
                              { AutoCommit => 1, });

   $dbh->{InactiveDestroy}  = 1;         # Don't disconnect on fork/daemonize

   # Daemonize only after connecting and doing --ask-pass.
   my $daemon;
   if ( $o->get('daemonize') ) {
      $daemon = new Daemon(o=>$o);
      $daemon->daemonize();
      MKDEBUG && _d('I am a daemon now');
   }
   elsif ( $o->get('pid') ) {
      # We're not daemoninzing, it just handles PID stuff.
      $daemon = new Daemon(o=>$o);
      $daemon->make_PID_file();
   }

   my $exit_status = 0; 
   my @servers_to_watch; 

   # Despite the name, recursing to slaves actually begins at the specified
   # server, so the named server may also be watched, if it's a slave.
   my $ms = new MasterSlave(VersionParser => $vp);
   $ms->recurse_to_slaves(
      {  dbh        => $dbh,
         dsn        => $dsn,
         dsn_parser => $dp,
         recurse    => $o->get('recurse') || 0,
         callback   => sub {
            my ( $dsn, $dbh, $level ) = @_;
            # Test whether we want to watch this server.
            eval {
               my $stat = $ms->get_slave_status($dbh);
               if ( $stat ) {
                  push @servers_to_watch, { dsn => $dsn, dbh => $dbh };
               }
               else {
                  die "could not find slave status on this server\n";
               }
            };
            if ( $EVAL_ERROR ) {
               chomp $EVAL_ERROR;
               MKDEBUG && _d('Not watching', $dp->as_string($dsn),
                  'because', $EVAL_ERROR);
            }
         },
         skip_callback => sub {
            my ( $dsn, $dbh, $level ) = @_;
            print STDERR "Skipping ", $dp->as_string($dsn), "\n";
         },
         method => $o->get('recursion-method'),
      }
   );

   # Watch each server found.
   my $must_fork = @servers_to_watch > 1;
   foreach my $host ( @servers_to_watch ) {

      $host->{dbh}->{InactiveDestroy}  = 1;         # Don't disconnect on fork

      # Fork, but only if there might be more than one host to watch.
      my $pid = $must_fork ? fork() : undef;
      if ( !$must_fork || (defined($pid) && $pid == 0) ) {
         # I either forked and I'm a child, or I didn't fork... confusing, eh?
         watch_server($host->{dsn}, $host->{dbh}, $must_fork, $ms);
      }
      elsif ( $must_fork && !defined($pid) ) {
         die("Unable to fork!");
      }
      # I already exited if I'm a child, so I'm the parent.  (Or maybe I never
      # forked).
      $children{$dp->as_string($host->{dsn})} = $pid if $must_fork;
   }

   MKDEBUG && _d('Child PIDs:', values %children);
   # Wait for the children to exit.
   foreach my $host ( keys %children ) {
      MKDEBUG && _d('Waiting to reap', $host);
      my $pid = waitpid($children{$host}, 0);
      $exit_status ||= $CHILD_ERROR >> 8;
   }

   $dp->disconnect($dbh);
   return $exit_status;
}

# ############################################################################
# Subroutines.
# ############################################################################

# Actually watch a server.  If many instances are being watched, this is
# fork()ed.
sub watch_server {
   my ( $dsn, $dbh, $was_forked, $ms ) = @_;

   MKDEBUG && _d('Watching server', $dp->as_string($dsn),
      'forked:', $was_forked);

   my $start_sql = $vp->version_ge($dbh, '4.0.5')
                 ? 'START SLAVE' : 'SLAVE START';
   if ( $o->get('until-master') ) {
      my ( $file, $pos ) = split(',', $o->get('until-master'));
      $start_sql .= " UNTIL MASTER_LOG_FILE = '$file', MASTER_LOG_POS = $pos";
   }
   elsif ( $o->get('until-relay') ) {
      my ( $file, $pos ) = split(',', $o->get('until-relay'));
      $start_sql .= " UNTIL RELAY_LOG_FILE = '$file', RELAY_LOG_POS = $pos";
   }

   my $set_skip   = $dbh->prepare("SET GLOBAL SQL_SLAVE_SKIP_COUNTER = "
                    . $o->get('skip-count'));
   my $start      = $dbh->prepare($start_sql);
   my $stop       = $dbh->prepare('STOP SLAVE');
   my $chmt       = $dbh->prepare(
                    'CHANGE MASTER TO MASTER_LOG_FILE=?, MASTER_LOG_POS=?');


   # ########################################################################
   # Lookup tables of things to do when a problem is detected.
   # ########################################################################
   my @error_patterns = (
      [ qr/You have an error in your SQL/         => 'refetch_relay_log' ],
      [ qr/Could not parse relay log event entry/ => 'refetch_relay_log' ],
      [ qr/Incorrect key file for table/          => 'repair_table'      ],
      # This must be the last one.  It's a catch-all rule: skip and restart.
      [ qr/./                                     => 'skip'              ],
   );

   # ########################################################################
   # These are actions to take when an error is found.
   # ########################################################################
   my %actions = (
      refetch_relay_log => sub {
         my ( $stat, $dbh ) = @_;
         MKDEBUG && _d('Found relay log corruption');
         # Can't do CHANGE MASTER TO with a running slave.
         $stop->execute();
         $chmt->execute(
            @{$stat}{qw(relay_master_log_file exec_master_log_pos)});
      },
      skip => sub {
         my ( $stat, $dbh ) = @_;
         MKDEBUG && _d('Found non-relay-log error');
         $set_skip->execute();
      },
      repair_table => sub {
         my ( $stat, $dbh ) = @_;
         MKDEBUG && _d('Found corrupt table');
         # [ qr/Incorrect key file for table './foo/bar.MYI'
         my ( $db, $tbl ) = $stat->{last_error} =~ m!([^/]+)/(.*?)\.MYI!;
         if ( $db && $tbl ) {
            my $sql = "REPAIR TABLE " . $q->quote($db, $tbl);
            MKDEBUG && _d($sql);
            $dbh->do($sql);
         }
      },
   );

   my $err_text  = $o->get('error-text');
   my $exit_time = time() + ($o->get('run-time') || 0);
   my $sleep     = $o->get('sleep');
   my ($last_log, $last_pos);

   my $stat = {}; # Will hold SHOW SLAVE STATUS
   STAT:
   while ( $stat
           && (!$o->get('run-time') || time() < $exit_time)
           && !-f $o->get('sentinel') ) {
      my $increase_sleep = 1;
      $stat = $ms->get_slave_status($dbh);
      if ( !$stat ) {
         print STDERR "No SLAVE STATUS output found on ",
            $dp->as_string($dsn), "\n";
         next STAT;
      }

      MKDEBUG && _d('Last/current relay log file:',
         $last_log, $stat->{relay_log_file});
      MKDEBUG && _d('Last/current relay log pos:',
         $last_pos, $stat->{relay_log_pos});
      if ( !$last_log
           || $last_log ne $stat->{relay_log_file}   # Avoid infinite loops
           || $last_pos != $stat->{relay_log_pos}
      ) {
         $stat->{slave_sql_running} ||= 'No';
         $stat->{last_error}        ||= '';
         $stat->{last_errno}        ||= 0;

         if ( $o->get('until-master') && pos_ge($stat, 'master') ) {
            die "Slave has advanced past " . $o->get('until-master')
               . " on master.\n";
         }
         elsif ( $o->get('until-relay') && pos_ge($stat, 'relay') ) {
            die "Slave has advanced past " . $o->get('until-relay')
               . " in relay logs.\n";
         }

         if ( $stat->{slave_sql_running} eq 'No' ) {
            # Print the time, error, etc
            if ( $o->get('verbose') ) {
               my $err = '';
               if ( $o->get('verbose') > 1 ) {
                  ($err = $stat->{last_error} || '' ) =~ s/\s+/ /g;
                  if ( $o->get('error-length') ) {
                     $err = substr($err, 0, $o->get('error-length'));
                  }
               }
               printf("%s %s %s %11d %d %s\n",
                  ts(time),
                  $dp->as_string($dsn),
                  $stat->{relay_log_file},
                  $stat->{relay_log_pos},
                  $stat->{last_errno} || 0,
                  $err
               );
            }

            if ( $o->got('error-numbers') 
                 && !exists($o->get('error-numbers')->{$stat->{last_errno}}) ) {
               die "Error $stat->{last_errno} is not in --error-numbers.\n";
            }
            elsif ( $err_text
                    && $stat->{last_error}
                    && $stat->{last_error} !~ m/$err_text/ ) {
               die "Error does not match --error-text.\n";
            }
            elsif ( $stat->{last_error} || $o->get('always') ) {

               # What kind of error is it?
               foreach my $pat ( @error_patterns ) {
                  if ( $stat->{last_error} =~ m/$pat->[0]/ ) {
                     $actions{$pat->[1]}->($stat, $dbh);
                     last;
                  }
               }

               $start->execute();
               $increase_sleep = 0;

               # Only set this on events I tried to restart.  Otherwise there
               # could be a race condition: I see it, I record it, but it hasn't
               # caused an error yet; so I won't try to restart it when it does.
               # (The point of this is to avoid trying to restart the same event
               # twice in case another race condition happens -- I restart it,
               # then check the server and it hasn't yet cleared the error
               # message and restarted the SQL thread).
               if ( $o->get('check-relay-log') ) {
                  $last_log = $stat->{relay_log_file};
                  $last_pos = $stat->{relay_log_pos};
               }
            }
            else {
               MKDEBUG && _d('The slave is stopped, but without error');
               $increase_sleep = 1;
            }
         }
         elsif ( $o->get('verbose') > 2 ) {
            printf("%s delayed %s sec\n", $dp->as_string($dsn),
               (defined $stat->{seconds_behind_master} ?
               $stat->{seconds_behind_master} : 'NULL'));
         }
      }
      else {
         if ( $o->get('verbose') ) {
            print "Not checking slave because relay log file or position has "
               . "not changed "
               . "(file " . ($last_log || '')
               . " pos "  . ($last_pos || '') . ")\n";
         }
      }

      # Adjust sleep time.
      if ( $increase_sleep ) {
         $sleep = min($o->get('max-sleep'), $sleep * 2);
      }
      else {
         $sleep = max($o->get('min-sleep'), $sleep / 2);
      }

      # Errors are very likely to follow each other in quick succession.  NOTE:
      # this policy has a side effect with respect to $sleep.  Suppose $sleep is
      # 512 and mk-slave-restart finds an error; now $sleep is 256, but
      # mk-slave-restart sleeps only 1 (the initial value of --sleep).  Suppose
      # there is no error when it wakes up after 1 second, because 1 was too
      # short.  Now it doubles $sleep, back to 512.  $sleep has the same value
      # it did before the error was ever found.
      my $sleep_time = $increase_sleep ? $sleep : min($sleep, $o->get('sleep'));
      if ( $o->get('verbose') > 2 ) {
         printf("%s sleeping %f\n", $dp->as_string($dsn), $sleep_time);
      }
      sleep $sleep_time;
   }

   MKDEBUG && _d('All done with server', $dp->as_string($dsn));
   if ( $was_forked ) {
      $dp->disconnect($dbh);
      exit(0);
   }
}

# Determines if the $stat's log coordinates are greater than or equal to the
# desired coordinates. $which is 'master' or 'relay'
sub pos_ge {
   my ( $stat, $which ) = @_;
   my $fmt  = '%s/%020d';
   my $curr = $which eq 'master'
      ? sprintf($fmt, @{$stat}{qw(relay_master_log_file exec_master_log_pos)})
      : sprintf($fmt, @{$stat}{qw(relay_log_file relay_log_pos)});
   my $stop = sprintf($fmt, split(',', $o->get("until-$which")));
   return $curr ge $stop;
}

sub ts {
   my ( $time ) = @_;
   my ( $sec, $min, $hour, $mday, $mon, $year )
      = localtime($time);
   $mon  += 1;
   $year += 1900;
   return sprintf("%d-%02d-%02dT%02d:%02d:%02d",
      $year, $mon, $mday, $hour, $min, $sec);
}

# Catches signals for exiting gracefully.
sub finish {
   my ($signal) = @_;
   print STDERR "Exiting on SIG$signal.\n";
   if ( %children ) {
      kill 9, values %children;
      print STDERR "Signaled ", join(', ', values %children), "\n";
   }
   exit(1);
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

# ############################################################################
# Run the program.
# ############################################################################
if ( !caller ) { exit main(@ARGV); }

1; # Because this is a module as well as a script.

# ############################################################################
# Documentation.
# ############################################################################

=pod

=head1 NAME

mk-slave-restart - Watch and restart MySQL replication after errors.

=head1 SYNOPSIS

Usage: mk-slave-restart [OPTION...] [DSN]

mk-slave-restart watches one or more MySQL replication slaves for
errors, and tries to restart replication if it stops.

=head1 RISKS

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-restart is a brute-force way to try to keep a slave server running when
it is having problems with replication.  Don't be too hasty to use it unless you
need to.  If you use this tool carelessly, you might miss the chance to really
solve the slave server's problems.

At the time of this release there is a bug that causes an invalid
C<CHANGE MASTER TO> statement to be executed.

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

See also L<"BUGS"> for more information on filing bugs and getting help.

=head1 DESCRIPTION

mk-slave-restart watches one or more MySQL replication slaves and tries to skip
statements that cause errors.  It polls slaves intelligently with an
exponentially varying sleep time.  You can specify errors to skip and run the
slaves until a certain binlog position.

Note: it has come to my attention that Yahoo! had or has an internal tool
called fix_repl, described to me by a past Yahoo! employee and mentioned in
the first edition of High Performance MySQL.  Apparently this tool does the
same thing.  Make no mistake, though: this is not a way to "fix replication."
In fact I would not even encourage its use on a regular basis; I use it only
when I have an error I know I just need to skip past.

=head1 OUTPUT

If you specify L<"--verbose">, mk-slave-restart prints a line every time it sees
the slave has an error.  See L<"--verbose"> for details.

=head1 SLEEP

mk-slave-restart sleeps intelligently between polling the slave.  The current
sleep time varies.

=over

=item *

The initial sleep time is given by L<"--sleep">.

=item *

If it checks and finds an error, it halves the previous sleep time.

=item *

If it finds no error, it doubles the previous sleep time.

=item *

The sleep time is bounded below by L<"--min-sleep"> and above by
L<"--max-sleep">.

=item *

Immediately after finding an error, mk-slave-restart assumes another error is
very likely to happen next, so it sleeps the current sleep time or the initial
sleep time, whichever is less.

=back

=head1 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, or of the last forked process that exited if there were multiple
servers to monitor.

=head1 COMPATIBILITY

mk-slave-restart should work on many versions of MySQL.  Lettercase of many
output columns from SHOW SLAVE STATUS has changed over time, so it treats them
all as lowercase.

=head1 OPTIONS

This tool accepts additional command-line arguments.  Refer to the
L<"SYNOPSIS"> and usage information for details.

=over

=item --always

Start slaves even when there is no error.  With this option enabled,
mk-slave-restart will not let you stop the slave manually if you want to!

=item --ask-pass

Prompt for a password when connecting to MySQL.

=item --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.

=item --[no]check-relay-log

default: yes

Check the last relay log file and position before checking for slave errors.

By default mk-slave-restart will not doing anything (it will just sleep)
if neither the relay log file nor the relay log position have changed since
the last check.  This prevents infinite loops (i.e. restarting the same
error in the same relay log file at the same relay log position).

For certain slave errors, however, this check needs to be disabled by
specifying C<--no-check-relay-log>.  Do not do this unless you know what
you are doing!

=item --config

type: Array

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

=item --daemonize

Fork to the background and detach from the shell.  POSIX
operating systems only.

=item --database

short form: -D; type: string

Database to use.

=item --defaults-file

short form: -F; type: string

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

=item --error-length

type: int

Max length of error message to print.  When L<"--verbose"> is set high enough to
print the error, this option will truncate the error text to the specified
length.  This can be useful to prevent wrapping on the terminal.

=item --error-numbers

type: hash

Only restart this comma-separated list of errors.  Makes mk-slave-restart only
try to restart if the error number is in this comma-separated list of errors.
If it sees an error not in the list, it will exit.

The error number is in the C<last_errno> column of C<SHOW SLAVE STATUS>.

=item --error-text

type: string

Only restart errors that match this pattern.  A Perl regular expression against
which the error text, if any, is matched.  If the error text exists and matches,
mk-slave-restart will try to restart the slave.  If it exists but doesn't match,
mk-slave-restart will exit.

The error text is in the C<last_error> column of C<SHOW SLAVE STATUS>.

=item --help

Show help and exit.

=item --host

short form: -h; type: string

Connect to host.

=item --log

type: string

Print all output to this file when daemonized.

=item --max-sleep

type: float; default: 64

Maximum sleep seconds.

The maximum time mk-slave-restart will sleep before polling the slave again.
This is also the time that mk-slave-restart will wait for all other running
instances to quit if both L<"--stop"> and L<"--monitor"> are specified.

See L<"SLEEP">.

=item --min-sleep

type: float; default: 0.015625

The minimum time mk-slave-restart will sleep before polling the slave again.
See L<"SLEEP">.

=item --monitor

Whether to monitor the slave (default).  Unless you specify --monitor
explicitly, L<"--stop"> will disable it.

=item --password

short form: -p; type: string

Password to use when connecting.

=item --pid

type: string

Create the given PID file when daemonized.  The file contains the process
ID of the daemonized instance.  The PID file is removed when the
daemonized instance exits.  The program checks for the existence of the
PID file when starting; if it exists and the process with the matching PID
exists, the program exits.

=item --port

short form: -P; type: int

Port number to use for connection.

=item --quiet

short form: -q

Suppresses normal output (disables L<"--verbose">).

=item --recurse

type: int; default: 0

Watch slaves of the specified server, up to the specified number of servers deep
in the hierarchy.  The default depth of 0 means "just watch the slave
specified."

mk-slave-restart examines C<SHOW PROCESSLIST> and tries to determine which
connections are from slaves, then connect to them.  See L<"--recursion-method">.

Recursion works by finding all slaves when the program starts, then watching
them.  If there is more than one slave, C<mk-slave-restart> uses C<fork()> to
monitor them.

This also works if you have configured your slaves to show up in C<SHOW SLAVE
HOSTS>.  The minimal configuration for this is the C<report_host> parameter, but
there are other "report" parameters as well for the port, username, and
password.

=item --recursion-method

type: string

Preferred recursion method used to find slaves.

Possible methods are:

  METHOD       USES
  ===========  ================
  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-restart 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.

=item --run-time

type: time

Time to run before exiting.  Causes mk-slave-restart to stop after the specified
time has elapsed.  Optional suffix: s=seconds, m=minutes, h=hours, d=days; if no
suffix, s is used.

=item --sentinel

type: string; default: /tmp/mk-slave-restart-sentinel

Exit if this file exists.

=item --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.

=item --skip-count

type: int; default: 1

Number of statements to skip when restarting the slave.

=item --sleep

type: int; default: 1

Initial sleep seconds between checking the slave.

See L<"SLEEP">.

=item --socket

short form: -S; type: string

Socket file to use for connection.

=item --stop

Stop running instances by creating the sentinel file.

Causes C<mk-slave-restart> to create the sentinel file specified by
L<"--sentinel">.  This should have the effect of stopping all running
instances which are watching the same sentinel file.  If L<"--monitor"> isn't
specified, C<mk-slave-restart> will exit after creating the file.  If it is
specified, C<mk-slave-restart> will wait the interval given by
L<"--max-sleep">, then remove the file and continue working.

You might find this handy to stop cron jobs gracefully if necessary, or to
replace one running instance with another.  For example, if you want to stop
and restart C<mk-slave-restart> every hour (just to make sure that it is
restarted every hour, in case of a server crash or some other problem), you
could use a C<crontab> line like this:

 0 * * * * mk-slave-restart --monitor --stop --sentinel /tmp/mk-slave-restartup

The non-default L<"--sentinel"> will make sure the hourly C<cron> job stops
only instances previously started with the same options (that is, from the
same C<cron> job).

See also L<"--sentinel">.

=item --until-master

type: string

Run until this master log file and position.  Start the slave, and retry if it
fails, until it reaches the given replication coordinates.  The coordinates are
the logfile and position on the master, given by relay_master_log_file,
exec_master_log_pos.  The argument must be in the format "file,pos".  Separate
the filename and position with a single comma and no space.

This will also cause an UNTIL clause to be given to START SLAVE.

After reaching this point, the slave should be stopped and mk-slave-restart
will exit.

=item --until-relay

type: string

Run until this relay log file and position.  Like L<"--until-master">, but in
the slave's relay logs instead.  The coordinates are given by relay_log_file,
relay_log_pos.

=item --user

short form: -u; type: string

User for login if not current user.

=item --verbose

short form: -v; cumulative: yes; default: 1

Be verbose; can specify multiple times.  Verbosity 1 outputs connection
information, a timestamp, relay_log_file, relay_log_pos, and last_errno.
Verbosity 2 adds last_error.  See also L<"--error-length">.  Verbosity 3 prints
the current sleep time each time mk-slave-restart sleeps.

=item --version

=back

Show version and exit.

=head1 DSN OPTIONS

These DSN options are used to create a DSN.  Each option is given like
C<option=value>.  The options are case-sensitive, so P and p are not the
same option.  There cannot be whitespace before or after the C<=> and
if the value contains whitespace it must be quoted.  DSN options are
comma-separated.  See the L<maatkit> manpage for full details.

=over

=item * A

dsn: charset; copy: yes

Default character set.

=item * D

dsn: database; copy: yes

Default database.

=item * F

dsn: mysql_read_default_file; copy: yes

Only read default options from the given file

=item * h

dsn: host; copy: yes

Connect to host.

=item * p

dsn: password; copy: yes

Password to use when connecting.

=item * P

dsn: port; copy: yes

Port number to use for connection.

=item * S

dsn: mysql_socket; copy: yes

Socket file to use for connection.

=item * u

dsn: user; copy: yes

User for login if not current user.

=back

=head1 DOWNLOADING

You can download Maatkit from Google Code at
L<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 C<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.

=head1 ENVIRONMENT

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

   MKDEBUG=1 mk-....

When L<"--daemonize"> is given and this variable is set, output is directed to a
debug file in C</tmp>.

=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 BUGS

For a list of known bugs see L<http://www.maatkit.org/bugs/mk-slave-restart>.

Please use Google Code Issues and Groups to report bugs or request support:
L<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 L<"--version">, and if possible, debugging output produced by
running with the C<MKDEBUG=1> environment variable.

=head1 COPYRIGHT, LICENSE AND WARRANTY

This program is copyright 2007-2011 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
MERCHANTABILITY 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 SEE ALSO

See also L<mk-table-checksum>, L<mk-table-sync>, L<mk-slave-delay>.

=head1 AUTHOR

Baron Schwartz

=head1 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. 

=head1 VERSION

This manual page documents Ver 1.0.22 Distrib 7540 $Revision: 7531 $.

=cut