Scripting: what is the response object used for when processing a request?

This may be a "RTM" question but here goes. The docs on lineratesystems.com do a good job at explaining how to use the HTTP request object. And I believe that the response object is for manipulating (or setting) what the LineRate will send back to the client.

So my question is how do I get at the server response?

Abridged code with my question in the middle:

var vsm = require('lrs/virtualServerModule');

var vs; // will be assigned in onRequest
var pidinfo = "(PID " + process.pid + "): ";

// Log to a database
var connection = mysql.createConnection({
  <>
});

var onRequest = function(request, response, next ) {
  // do some processing

  // Add the record to the database automatically if they don't already exist
  // Here I would store the time (in ms) that the connection came in
  connection.query('INSERT INTO urls (uri) select * FROM (SELECT "' + connection.escape(request.url) + '") as tmp \
                    WHERE NOT EXISTS(SELECT uri from urls where uri="' + connection.escape(request.url) + '")', function(err, rows, fields) {
      if (err) throw err;

    // Here we make the server pick
    connection.query('SELECT opt_in from urls where uri="' + connection.escape(request.url) + '"', function(err, rows, fields) {
      if (err) throw err;
      var opt_in = rows[0].opt_in;
      if( !opt_in ) {
        // HERE IS WHERE MY QUESTION IS - where does the response go, and how can I hook into it so I can process the other timestamp?
        vs_a.newRequest(request, response, next);
        return;
      } else {
        vs_b.newRequest(request, response, next);
        return;
      }
    });
  });
}; 
// onRequest


var onExist = function(the_vs) {
    if(the_vs.id == 'Bugzilla') {
    connection.connect();
    console.log( pidinfo + "Database connected.");
    logged_in = true;

    vs = the_vs;
    vs.on('request', onRequest);

  }
};

vsm.on('exist', 'Bugzilla', onExist);