Caching Express Server using Redis. (REDIS-STACK Docker Image)

Points to know

• Redis is key-value pair in-memory(RAM) database
• One string value limit is 512 MB.

Installation

• Setup Redis server with Redis-Stack (GUI) using docker images

  docker run -d --name redis-stack -p 6379:6379 -p 8001:8001 redis/redis-stack:latest

  --name = name of container i.e redis-stack which is anything given by user
  -d   = it runs container in background (detached mode)
  -p   = map port 6379 to 6379 where 6379 is redis server default port
  -p   = map port 8001 to 8001 where 8001 is redis-stack (gui) default port
  redis-stack/latest  = latest of version of redis-stack server

  At first, the image will not be found in our system, then docker automatically fetch from the docker hub where the redis-stack image is hosted/located. and then will run the images.

  After succesfully image run we can see the gui of redis in port localhost:8001

• Navigate to docker container where our redis server is located

  docker exec -it containerId bash
  
  -it  = interactive mode where we can write, delete, edit, ..
  bash = open bash terminal where we can put command

• Test if redis-cli is exists in bash or not

  redis-cli ping
  
  redis-cli = entry command 
  Result = PONG

• Open redis-cli

  redis-cli

• Store data in redis in key-value pair

  set <entity>:<id> value
  
  i.e
  
  set user:name parbat
  set user:age 12
  
  user:name, user:age = key
  parbat, 12 = value
  
  **Set multiple key value**
  
  *mset user:name "hacker" message:1 "Ola gamostas"*

• Get data from key

  get <entity>:<id>
  i.e
  get user:name
  get user:age
  
  G**et multiple key value**
  
  *mget user:name message:1*

• Store data only if key doesn’t exists using (nx) and called Locks

  set <entity>:<id> value nx

• Counter increment/decrement using incre incrby decr decrby

  set count 0
  
  incr count                        result= 1
  
  incrby count 10                   result= 10
  
  decr count                        result= 9
  
  decrby count 5                    result= 4