Best way to cache in Node.js

Question

I am trying to find the best caching solution for a node app. There a few modules which can manage this. Most popular being: https://www.npmjs.com/package/node-cache

But I found that responses are faster if I just save some results into a variable like:

var cache = ["Kosonsoy","Pandean","Ḩadīdah","Chirilagua","Chattanooga","Hebi","Péruwelz","Pul-e Khumrī"];

I can then update that variable on a fixed interval, is this also classed as caching? Are there any known issues/problems to this method. As it defiantly provides the fastest response times.

Answer 1

Of course it is faster as you use local memory to store the data. For limited cache size this is good, but can quickly eat up all your process memory.

I would advise to use modules as there is a considerable amount of collaborative brainpower invested in them. Alternatively you can use a dedicated instance to run something like Redis to use as cache.

Alternatives aside, if you would stick with your solution I recommend small improvement.

Instead of

var cache = ["Kosonsoy","Pandean","Ḩadīdah","Chirilagua","Chattanooga","Hebi","Péruwelz","Pul-e Khumrī"];

try using objects as key value storage.

This will make searching and updating entries faster.

var cache = {"Kosonsoy":data,"Pandean":moreData,...};

Searching in array requires iterations while accessing the object is as simple as

var storedValue = cache["Kosonosoy"];

saving

cache[key] = value;

Answer 2

If you use many workers you will have a duplicated cache for each one because they have no shared memory.

Of course, you can use it for small data. And keeping a data in a variable for an amount of time can be called caching for me.