$re = '/was\s+down\s+for\s+(?<hours>\d+)hr:(?<minutes>\d+)min:(?<seconds>\d+)sec /m';
$str = '<133>Feb 13 13:01:33 slot2/US66666-CORE-LTM1.company.COM notice mcpd[8701]: 01070727:5: Pool /Common/pool-generic member /Common/servernamew006:8080 monitor status up. [ /Common/mon-xxx-prod-xxx-liveness: up ] [ was down for 0hr:0min:15sec ]';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php