$re = '/\[\d{2}\.\d{2}\.\d{2}\s\d{2}\:\d{2}\:\d{2}\:\d{1,3}\sMET\].+The Application\s([a-zA-Z0-9]*)\sis starting\.[\s\S]*\[\d{2}\.\d{2}\.\d{2}\s\d{2}\:\d{2}\:\d{2}\:\d{1,3}\sMET\].+The Application started:\s\1/m';
$str = '[10.12.19 15:29:10:408 MET] 0000006a ApplicationMg A WSVR0200I: The Application query is starting.
[10.12.19 15:29:11:102 MET] 0000006a CompositionUn A WSVR0191I: Composition unit AB started
[10.12.19 15:29:11:222 MET] 0000006a CompositionUn A WSVR0191I: Composition unit CD started
[10.12.19 15:29:11:412 MET] 0000006a ApplicationMg A WSVR0200I: The Application tracer is starting.
[10.12.19 15:29:12:108 MET] 0000006a CompositionUn A WSVR0191I: Composition unit DE started.
[10.12.19 15:29:12:541 MET] 0000006a ApplicationMg A WSVR0200I: The Application started: query
[10.12.19 15:29:13:417 MET] 0000006a ApplicationMg A WSVR0200I: The Application started: tracer
[10.12.19 15:30:12:145 MET] 0000006a ApplicationMg A WSVR0200I: The Application test is starting.
[10.12.19 15:30:13:408 MET] 0000006a CompositionUn A WSVR0191I: Composition unit XY started.
[10.12.19 15:30:14:678 MET] 0000006a ApplicationMg A WSVR0200I: The Application started: test';
preg_match_all($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