Task - create a cache exploiting redis

Created by: benoitdm-oslandia

Create a cache exploiting redis

In the case of a deployment with horizontal scalability, the cache will be different from one instance to another. To overcome this problem, we can use a Redis instance which will store the cache!

Useful links

• https://github.com/gorilla/mux/tree/v1.8.0

• https://github.com/alrf/go_redis_pg

• https://github.com/DenChenn/shorturl-maker

• Middleware :

• https://www.honeybadger.io/blog/go-web-services/
• https://www.honeybadger.io/blog/ruby-to-go-4/
• https://dev.to/franciscomendes10866/caching-in-golang-using-redis-418n

Steps

Install a Redis server

• Install a Redis server first

Implementation external to the project

Update configuration

• Add process option or env variable to enable use of Redis cache
• Add Redis configuration (toml)
• Initialize the Redis connection

Set up an implementation logic

• Set up an implementation logic

[GET] :
if the data is not available in the Redis cache,

• we will look for it in the database
• we save it in the Redis cache

[GET] :
if the data is not available either in the Redis cache or in the database, we save the information of non-existence in the Redis cache

[POST] :
we always save new data in the Redis cache

[PATCH | PUT] :
save the data modification in the Redis cache, by overwriting the old cache

:eye_speech_bubble: Redis stores keys/values

• Ex. etag: {...} // réponse json d'une collection

:eye_speech_bubble: where to add the redis instructions?

we will use the available Cacher interface

Implement the new Cacher interface RedisCache

• check : ContainsWeakEtag
• set : AddWeakEtag
• get : getRedis()
• clear : RemoveWeakEtag

cf. comment: implementation examples

Add unit test

• Add Redis cache usage test

Benchmark

• Set up a benchmark with/without Redis cache

• Charge test

Implementation internal to the project

• Install K6

https://github.com/grafana/k6

• Write K6 tests
  • Set up in CI
  • Visualization of results in K6 Cloud