User signup with Node and Redis

createUser

function createUser(raw, success_cb, fail_cb) {

  var userId;

  console.log("enter");

  async.waterfall([
    function(cb) {
      // Increase
      client.hincrby('users', 'count', 1, cb);
    },
    function(id, cb) {
      // Higher Scope a userId variable for access later.
      userId = id;
      console.log(userId);
      // Set
      client.hmset('user:'+id, 
        'username', raw.username, 
        'password', raw.password, 
        'email', raw.email, 
        cb);
    },
    function(write, cb) {
      client.hmget('user:'+userId, 'username', 'email', cb);
    }
  ], function(err,read){
      if (err) {
        fail_cb(err);
      }
      success_cb(userId, read);
  })
};

function createUser(raw, success_cb, fail_cb) {

 var userId;

 client.incrAsync('users.count').then(function(id){
        userId = id;
        return client.hmsetAsync(
            'user:' + id,
            'username', raw.username,
            'password', raw.password,
            'email', raw.email
        );
      }).then(function() {
         client.setAsync("username.to.id:" + raw.username.toLowerCase(), userId);
      }).then(function(){
        return client.hmgetAsync('user:'+userId, 'username', 'email');
    }).then(function(data) {
      success_cb(userId, data);
    }).catch(function(err){
      fail_cb(err);
    });
};