tweak various mongoose settings to observe cpu impact.

mongoose-cpu-load-test.js

/**
 * configuration
 */

// connection pool size
var poolSize = 5;

// number of parallel queries
var n = 60;

// size of each document
var size = 1024;

// milliseconds between each test
var time = 50;

// exclude the "name" property
var excludeName = false;

// skip mongoose hydration overhead
var lean = false;



/**
 * dependencies
 */

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var assert = require('assert')

console.log('\n===========');
console.log('    mongoose version: %s', mongoose.version);
console.log('========\n\n');

/**
 * uri
 */

var uri = process.env.MONGOOSE_SET_TEST_URI || 'mongodb://localhost';
var dbname = 'goosetest-1666';

mongoose.connect(uri + '/' + dbname, { server: { poolSize: poolSize }});
mongoose.connection.on('error', function () {
  console.error('connection error', arguments);
});

/**
 * Model
 */

var schema = new Schema({
    name: String
  , _id: Number
});
var A = mongoose.model('A', schema);

// create dummy docs at configured size
function makeDocs (cb) {
  var docs = [];
  for (var i = 0; i < n; ++i) (function(i){
    docs.push({ _id: i, name: new Array(size*1024).join('x') });
  })(i);
  A.create(docs, cb);
  docs = null;
}

mongoose.connection.on('open', function () {
  mongoose.connection.db.dropDatabase(function () {
    makeDocs(function (err) {
      if (err) return close(err);
      console.log('created %d docs', arguments.length-1);

      function test () {
        var start = new Date;
        var count = n;

        function done () {
          --count || next();
        }

        function next () {
          console.log('read of %d docs finished in %d seconds', n, (new Date - start)/1000);
          setTimeout(test, time);
        }

        for (var i = 0; i < n; ++i) {
          var query = A.findById(i)
          if (excludeName) query.select('-name');
          if (lean) query.lean();
          query.exec(done);
        }
      }

      test();
    })
  });
});

function close (err) {
  console.log(err);
  mongoose.disconnect();
}