Mongoose Average Query Example

gistfile1.js

var CpuUtilization = require('./models/cpu_utilization');

CpuUtilization.aggregate({
	// $match: { instance_id: { $gte: 21 }}
	$match : {
		instance_id : 'i-2d800b2a',
		time_stamp : {
//			$lt : new Date('Tue Jan 21 2014 19:31:00 GMT+0900 (대한민국 표준시)')
			$lt : new Date('2014-01-21 10:31:00.000Z')
		}
	}
}).group({
	_id : '$instance_id',
	markAvg : {
		$avg : '$average'
	}
}).exec(function(err, res) {
	if (err) {
		console.log(err);
	} else {
		console.log(res);
	}
});