Round robin DNS records are a technique for distributing load across public facing web servers. As an experiment we tried using them in order to distribute load inside of a cluster. We found this approach didn’t work. In this post I’ll discuss round robin load balancing, how it works at a high level, what we did with DNS, why it didn’t work, and what can be done instead. ...

For the love of all that is dear to software development avoid parallel but separate class hierarchies. Today we’re going to talk a little bit about type hierarchy design and why composition is useful to consider in certain scenarios. ...

Performance counters can be implemented in applications to help operators determine where bottlenecks are in the design. Microsoft has a decent page, that’s somewhat Windows centric, about performance counters. This post is about implementing the most basic type of counter, a value which monotonically increases, in JavaScript for NodeJS and the performance implications of different designs. ...

A 1stgeneration software product will likely miss the mark. It might have missed being that best that it could be by costing too much, being too complex, or just not targeting the right market. In any case, a 1stproduct may lead to another, 2nd, product that is cheaper, simpler, or just hits the right notes with the intended customer. Today’s post is about building the wrong product (the 1stone) in the right way so that the 2ndproduct can be built better, faster. ...

Note I didn’t say always should export objects, but for the sanity of everyone involved, in many cases a required module should return a constructor and not a fully instantiated object. Today’s post is about why your NodeJS modules should look like this: /** * @constructor */ function myConstructor(someDependency) { /* setup my object here */ } module.exports = myConstructor; and not this: var myObj = { myService: new MyService() }; myObj.myFunction = function(foo) { /* do stuff with foo here */ }; module.exports = myObj; ...

Operational monitoring of a software application is one of the activities the ensures a successful public launch. Too often it seems like a service’s course to public availability looks something like, Conceptualization → Development → … → SHIP IT. The “…” component is an important step at large enterprises with large public services (like Expedia, Amazon.com, etc) and involves developing a way to monitor an application whilst running it. At smaller organizations though I have seen this smaller step get discarded or not looked at. Today’s post offers a few thoughts on what logging and monitoring looks like today. ...

Recently I began work on a project to manage the deployment of a product built using a microservices architecture. As a result of our chosen architecture we have a large number of services which will communicate to each other over HTTP/S. Instead of using fixed IPs we decided to used DNS SRV records to indicate where services could contact their dependencies. Today’s post goes into using SRV records in a little more detail and the problem they solve. ...

In the last few weeks I have been slowly learning about the cocos2d-x framework. cocos2d-x is a C++ based cross platform game engine. The makers of the engine also produce a UI creation GUI called Cocos Studio. Today’s post is a brief one about loading scenes from Cocos Studio into a cocos2d-x based application. ...

I’ve written before about how it’s better to write straightforward code than trying to be clever and pre-optimize. Another example of where this rule is true is the cost of iteration between different styles of array loops in JavaScript when executed within NodeJS. ...

Operator precedence determines the order [Operator precedence determines the order]2 and binary operators are executed. In many situations, knowing basic mathematical operator precedence (for +,-,*, etc) is enough. In other situations not knowing the specifics of language can lead to hard to find errors. Quickly, in JavaScript what does 'the boogeyman ' + false ? 'is scary' : 'is not scary' evaluate to? ...