#! /usr/bin/perl
#
# Compare MASTER and SLAVE binlogs and if it's equal, PURGE old MASTER logs 
#
# (c) 2008 by Kocmuk.ru

use DBI;

# Auth for mysql
my $user="user";
my $passwd="pass";

# Put SLAVE server groups here
@server_list=(
    ["server_a2"], 
    ["server_b2"], 
    ["server_c2","server_c3"] 
);

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

my $debug = 0;

if ( $ARGV[0] eq "--do" ) {
	$debug = 0;
} else {
	print "Debug _read only_ mode: NOT realy purge anything.\n";
	$debug = 1;
}

#

foreach (@server_list) {
    my $master = "";
    my $binlog = "";
    my $error = 0;
#
    print "\nPoll slave-servers in the same group:\n";
#
    foreach $server (@$_) {
	unless ($dbh = DBI->connect ("DBI:mysql::host=$server", $user, $passwd, {RaiseError=>0, PrintError=>1, AutoCommit => 1})) { 
		print "Cann't connect to slave: slave=\"$server\"\n";
		$error=1;
		last;
 	}
	unless ($sth = $dbh->prepare("show slave status;")) {
		print "Cann't prepare to fetch slave status: slave=\"$server\"\n";
		$error = 1;
		last;
	}
	unless ($sth->execute()) {
		print "Cann't exec fetch slave status: slave=\"$server\"\n";
		$error = 1;
		last;
	}

	my @ary = $sth->fetchrow_array();
        my $smaster = $ary[1];
	my $sbinlog = $ary[9];

	unless ($smaster or $sbinlog) {
		print "Abnormal slave status: slave=\"$server\" with master=\"$smaster\" and binlog=\"$sbinlog\"\n";
		$error = 1;
		last;
	}
	print "Slave status: slave=\"$server\" with master=\"$smaster\" and binlog=\"$sbinlog\" \n";
        if ($master eq "") {
	    	$master = $smaster;
	} 
	elsif ($master ne $smaster) {
		print "Master name master=\"$smaster\" at slave=\"$server\" is different from the rest.\n";
		$error = 1;
		last;
	} 
	if ($binlog eq "") {
		$binlog = $sbinlog;
	}
	elsif ($binlog ne $sbinlog) {
		print "Binlog name binlog=\"$sbinlog\" at slave=\"$server\" is different from the rest.\n";
		$error = 1;
		last;
	} 
     }
#
     if ($error == 1) {
	print "Slave-servers poll is failed, go to next group.\n";
	next;
     } 
     else {
     	print "All slave-servers are consistent.\n";
    }
#
    unless ($dbh = DBI->connect ("DBI:mysql::host=$master", $user, $passwd, {RaiseError=>0, PrintError=>1, AutoCommit => 1})) {
	print "Cann't connect to master: master=\"$master\"\n";
	print "Go to next group.\n";
	next;
    }
    unless ($sth = $dbh->prepare("show master status;")) {
	print "Cann't prepare to fetch master status at: master=\"$master\"\n";
	print "Go to next group.\n";
	next;
    }
    unless ($sth->execute()) {
	print "Cann't exec fetch master status at: master=\"$master\"\n";
	print "Go to next group.\n";
	next;
    } 

    my @ary=$sth->fetchrow_array();
    my $masterbinlog = $ary[0];

    unless ($masterbinlog) {
	print "Abnormal master=\"$master\" status: binlog=\"$masterbinlog\"\n";
	print "Go to next group.\n";
	next;
    }

    print "Master master=\"$master\" with: binlog=\"$masterbinlog\"\n";

    if ($masterbinlog eq $binlog) {
        print "Master binlog=\"$masterbinlog\" and slave binlogs=\"$binlog\" are equal.\n";
        if ($debug == 0 ) {
        	print "PURGing MASTER LOGS TO '$masterbinlog' at $master...\n";
                unless ($sth2 = $dbh->prepare("PURGE MASTER LOGS TO '$masterbinlog';")) {
			print "Cann't prepare \"PURGE MASTER LOGS TO '$masterbinlog'\" at master=\"$master\"";
			print "Go to next group.\n";
			next;
		}
		unless ($sth2->execute()) {
			print "Cann't exec \"PURGE MASTER LOGS TO '$masterbinlog'\" at master=\"$master\"";
			print "Go to next group.\n";
			next;
		}
                print "...done.\n\n";
        } else {
                print "debug: \"PURGE MASTER LOGS TO '$masterbinlog'\" at master=\"$master\"\n";
                }
    } else {
        print "WARNING! master-binlog: \"$masterbinlog\" and slaves-binlog: \"$binlog\" are NOT equal!\n";
	print "Go to next group.\n";
        next;
    }
    
}