Getting started with Redis

What is redis

Redis (which stands for REmote DIctionary Server) is a popular, open-source, in-memory data store.

It is super-fast database because it keeps all its data in your computer's RAM (memory) instead of on a slower disk. This makes reading and writing data almost instantaneous.

Even if it is faster than postgres, it has some latest as it still needs to be writter and read from localhost.

It's a "key-value" store, meaning data is saved and retrieved using a simple key in a dictionary to find its definition (the value). It supports various data structures, including strings, lists, sets, and hashes, making it very flexible.

Common Use Cases

Because of its high speed, Redis is perfect for tasks that require real-time data access.

Caching: This is most populaer use case. Redis stores frequently accessed data (like database query results, web pages, or user profiles) in memory. This prevents the application from having to fetch that data from a slower database every time, dramatically speeding up response times.
Session Store: Redis is excellent for managing user session data (like login status, shopping cart contents, etc.) for web applications. Its speed ensures that user information is loaded instantly on every page.
Real-time Analytics: It's used to process and display real-time data, such as for live leaderboards in games, website visitor counters, or tracking real-time metrics.
Message Broker (Pub/Sub): Redis can create a "Publish/Subscribe" system. This allows different parts of an application to communicate with each other instantly, making it ideal for building chat rooms, live notification systems, or processing background jobs. This can be used instead of kafka.
Rate Limiting: It can be used to track how many requests a user makes to an API in a given timeframe, helping to prevent abuse or overload.

How to install

Ubuntu

First update the package index and then install redis

sudo apt update
sudo apt install redis-server

verify the installation

redis-server --version

Server related commands

# start the server
sudo systemctl start redis-server
# enable redis on boot
sudo systemctl enable redis-server
# check status
sudo systemctl status redis-server
# stop
sudo systemctl stop redis-server
restart
sudo systemctl restart redis-server

Start the CLI to test

redis-cli
# to exit the CLI
exit

Mac

Install Redis

brew install redis

verify the installation without starting the server

redis-server --version

Run service as background

brew services start redis

Run manually

redis-server

Check if it is running

redis-cli ping