Node Interactive North America 2017

Memory Leaks leading to undesired growth and exhaustion of memory are by far the most common production problem reported on enterprise scale Node applications. Closures, a powerful semantic feature in functional programs which are used pervasively in Node.js/Javascript programs to support their asynchronous and event driven programming model, are a prominent source of unanticipated memory leaks.
In this presentation, I will explain three of the most common use cases where Closures are used in Node. For each of the use cases, I will explain a) sample code, b) the life-span of the Closure context and which variables the closure keeps live, iii) what memory will be retained during the life-span of the Closure.