db.media.find({mediaContainer:"ContainerS3"}).forEach(function(e,i) {
e.url=e.url.replace("//a.n.com","//b.n.com");
db.media.save(e);
});
db.media.find({mediaContainer:"ContainerS3"}).forEach(function(e,i) {
e.url=e.url.replace("//a.n.com","//b.n.com");
db.media.save(e);
});