404 logging change

dont write to db on every 404
dont log 404 if route is empty

src/meta/errors.js

@@ -1,7 +1,9 @@
 'use strict';
 
 var async = require('async');
+var winston = require('winston');
 var validator = require('validator');
+var cronJob = require('cron').CronJob;
 
 var db = require('../database');
 var analytics = require('../analytics');
@@ -9,11 +11,39 @@ var analytics = require('../analytics');
 module.exports = function (Meta) {
 	Meta.errors = {};
 
+	var counters = {};
+
+	new cronJob('0 * * * * *', function () {
+		Meta.errors.writeData();
+	}, null, true);
+
+	Meta.errors.writeData = function () {
+		var dbQueue = [];
+		if (Object.keys(counters).length > 0) {
+			for (var key in counters) {
+				if (counters.hasOwnProperty(key)) {
+					dbQueue.push(async.apply(db.sortedSetIncrBy, 'errors:404', counters[key], key));
+				}
+			}
+			counters = {};
+			async.series(dbQueue, function (err) {
+				if (err) {
+					winston.error(err);
+				}
+			});
+		}
+	};
+
 	Meta.errors.log404 = function (route, callback) {
 		callback = callback || function () {};
+		if (!route) {
+			return setImmediate(callback);
+		}
 		route = route.replace(/\/$/, '');	// remove trailing slashes
 		analytics.increment('errors:404');
-		db.sortedSetIncrBy('errors:404', 1, route, callback);
+		counters[route] = counters[route] || 0;
+		counters[route] += 1;
+		setImmediate(callback);
 	};
 
 	Meta.errors.get = function (escape, callback) {