PHP does not connect to localhost MongoDB and fails silently -

i have php script this:

try {     $conn = new mongoclient("mongodb://localhost:27017");     var_dump($conn); } catch (mongoconnectionexception $e) {     var_dump($e); } 

when visited page, showed nothing. mongod shows no connection attempt, shell client works normally.

i'm running mongodb 2.4 on debian.

any appreciated, thanks!