stopping/starting slave while mysqldump'ing

[Ajay Sharma]

I wrote a quick php script to do my mysql backups. It goes like this:

- connect to slave db
- get a list of databases
- do a "SLAVE STOP"
- then run a bunch of mysqldump commands for each database
- do a "SLAVE START"

I'm fairly new to replication, is it pretty safe to start/stop the slave like that?

--Ajay

PS. here's the 0.1 version of the script in case anyone was curious:

---cut here----
#!/usr/bin/php -q
<?php

$user = '';
$pass = '';
$host = '';

$date = date("Ymdhm");

$dir = '/backup/dumps/per_db/';

$conn = @mysql_connect( $host,$user,$pass) or die( mysql_errno().': '.mysql_error());

// before we begin, stop the slave
$result = mysql_query("slave stop") or die('Slave Stop failed: ' . mysql_error());

$result = mysql_list_dbs( $conn );


// now dump each database
while( $row = mysql_fetch_object( $result ) ):
$db = $row->Database;
$filename = $dir . $date . "_" . $db . ".sql.tgz";

$command = "mysqldump -h $host -u$user -p$pass --opt -C $db | gzip -c > $filename";
echo "$command\n";
system($command);

endwhile;

mysql_free_result( $result );

//start up the slave before we leave
$result = mysql_query("slave start") or die('Slave Start failed: ' . mysql_error());
mysql_close( $conn );

?>