CODEWITHSUNDEEP
cachingmemoryredis
hh54188
hh54188

Reputation: 15626

Redis cache vs. using memory directly

I have not used Redis yet, but I have heard about it and plan to try using it for caching data.

I have heard that Redis uses memory as a cache store database. What's the point of Redis, since I can use an object or dictionary to store data? Like this:

var cache = {
    key: {
    
    },
    key: {
    
    }
    ...
}

What are the advantages of using Redis?

Upvotes: 231

Views: 110550

Answers (2)

Ashish Bainade
Ashish Bainade

Reputation: 506

My team likes using serverless architecture, where each request can go to a different container. In this case Redis can play a very important role.

We can't use a simple cache in serverless because we can't be sure our request will get served by the same container where our simple cache is stored. Redis is a good solution because it stores the cache at a remote location. We can access Redis from anywhere.

Upvotes: 20

Didier Spezia
Didier Spezia

Reputation: 73206

Redis is a remote data structure server. It is certainly slower than just storing the data in local memory (since it involves socket roundtrips to fetch/store the data). However, it also brings some interesting properties:

  • Redis can be accessed by all the processes of your applications, possibly running on several nodes (something local memory cannot achieve).

  • Redis memory storage is quite efficient, and done in a separate process. If the application runs on a platform whose memory is garbage collected (node.js, java, etc ...), it allows handling a much bigger memory cache/store. In practice, very large heaps do not perform well with garbage collected languages.

  • Redis can persist the data on disk if needed.

  • Redis is a bit more than a simple cache: it provides various data structures, various item eviction policies, blocking queues, pub/sub, atomicity, Lua scripting, etc ...

  • Redis can replicate its activity with a master/slave mechanism in order to implement high-availability.

Basically, if you need your application to scale on several nodes sharing the same data, then something like Redis (or any other remote key/value store) will be required.

Upvotes: 352

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