Spring Redis

Table of Contents

• What is Redis.
• Use Case
• Installation
  • Two methods
  • Installed and configure on MAC
• Backup
• Monitor
• Redis Sentinel
• Redis Auth
• Steps to run the application
  • Run both app and redis locally
  • Run both app and redis inside a container
  • Run both app and redis inside a container using docker-compose
• OpenAPI
• API Endpoint to access the app
• TO DO

What is Redis.

• Redis is a powerful and extremely fast in memory db.
• Stores data in key-value.
• Persistence.
• Optionally you can save the data to disk.
• Master slave replication.
• Highly Available.
• Open source.
• Indexing (Still can create own indexing).
• No query language.

Use Case

• User Session Management
• Caching.
• Pub/Sub (Queues & Notification)
• Leaderboards for gaming apps
• Geospatial

Installation

Two methods

• Download and installed. (Please use Redis Download to see the steps to configure the redis in other OS)
• Using package manager like brew (mac). (I will be using this to configure redis)

Installed and configure on MAC

• Open the terminal and type

  $ brew install redis
  

• Once it done, type redis-server to start the redis server with default configuration provided by redis.

  $ redis-server {path to the redis.conf}
  

• Open another terminal and type redis-cli, to open the redis cli.

  $ redis-cli -p 6379
  

  You will see the output something like below:

  $ redis-cli -p 6379
  127.0.0.1:6379>
  

  Checking redis status execute below

  $ redis-cli ping
  PONG
  

  killing redis server execute below

  127.0.0.1:6379> shutdown
  

• Some sample commands on redis-cli

   127.0.0.1:6379> set color red   #setting a value in color (as key) and red (as value)
   OK
   127.0.0.1:6379> keys *   # verifying total number of keys
   1) "\xac\xed\x00\x05t\x00\x04Book"
   2) "color"
   127.0.0.1:6379>
   127.0.0.1:6379>
   127.0.0.1:6379> get color  # getting the value assigned to the key - color
   "red"
   127.0.0.1:6379>
  

Backup

Below command will create the dump/backup as per the path specified in redis.conf file.

$ save

Monitor

Run the below command from terminal and you'll be abe to see everything happening on redis

 $ redis-cli -p 6379
 127.0.0.1:6379> Monitor
 OK

Redis Sentinel

• It is a system, designed to help managing Redis instances.
• It is there to provide HA by monitoring, notifying, and providing instances failover.
• It check whether master and slave are working properly or not.
• If Master goes down, it's the sentinel responsibility to make one of the slave to master.

Redis Auth

• Redis auth help to secure database. We can do that either via redis.conf or via cli.
• Cli

  $ config set requirepass ${auth-key}
  $ auth ${auth-key}
  
  

Extra links:

• Use RedisLabs to setup redis on cloud free.
• Redis GUI - Redis Desktop.

Steps to run the application

Run both app and redis locally

• Follow these steps to configure and run Redis locally.
• Execute below command to run the boot app from apps directory

 $./gradlew bootRun

• Alternatively, first build the jar and then run java -jar command as below

 $./gradlew build

 $ java -jar {name of the generated jar}

Run both app and redis inside a container

• Execute the below command from redis directory

$ docker network create rmoff_services
$ docker build -t redis-server .
$ docker run -d -p 6379:6379 --network=rmoff_services \
  --name redis \
  -h redis redis-server

• Build an image of the app. Execute below command from apps directory.

$ docker build -t backend-service .

• Verify the image

$ docker image ls -a

• Run the app

$ docker run -d --name app -e "REDIS_HOST=redis" \
 -p 8080:8080 --network=rmoff_services \
  backend-service

Run both app and redis inside a container using docker-compose

$ docker-compose -f docker-compose-stack.yaml up -d

Run both in K8s

• Execute below command to deploy the application in k8s and expose the same via service using nodeport.

$ kubectl apply -f k8s-deployment.yaml

OpenAPI

• http://localhost:8080/swagger-ui.html
• http://localhost:8080/api-docs

API Endpoint to access the app

• http://localhost:8080/api/health
• http://localhost:8080/api/book/save
• http://localhost:8080/api/book/all
• http://localhost:8080/api/book/delete/{id}

TO DO

• Add steps to run both container in K8s.