Build Your Own Redis Server (Python Edition)
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Introduction

Introduction
Learn About Redis
Step 0 - Setting Up

Step Goals
Installing Redis
Setting Up Python
Learn To Use Redis, Redis CLI And Redis Benchmark
Create A GitHub Repo For Your Project.
Step 1 - Introduction to RESP, Building a Protocol Handler Using Test-Driven Development

Introduction to RESP
Introduction to Test Driven Development
Using Test Driven Development to Build a Protocol Handler
Step 1 - Challenge: Protocol Handling
Step 1 - Solution: Protocol Handling
Step 2 - Creating a Network Client and Server

Introduction To Creating A Network Client And Server
Serialising the RESP Data Types
Building a Simple Redis CLI
Testing the CLI Against Redis
Sample Solution for a Simple Redis CLI
Step 2 - Challenge: Handling PING and ECHO Commands
Building a Simple Server To Handle Incoming Connections
Responding To The PING And ECHO Commands
Step 2 - Solution: Handling PING and ECHO Commands
Step 3 - Data Structures, Set and Get

Set Up Continuous Integration
Step 3 - Challenge: SET and GET
Adding The Core Data Structure
Handling The Set Command
Handling the Get command
Using the Redis CLI to test Set and Get
Step 3 - Solution: SET and GET
Step 4 - Handling Concurrency

Step 4 - Challenge: Handling Concurrent Clients
Threads Versus Async
Making The Data Store Thread-Safe
Handling Concurrent Clients With Threads
Using The Redis CLI And Redis Benchmark To Test Concurrency
Step 4 - Solution: Handling Concurrent Clients With Threads
Step 4 - Async Solution: Handling Concurrent Clients With Async IO
Step 5 - Implementing Expiry

Introducing The Two Methods Of Expiry
Step 5 - Challenge: Implementing Key Expiry
Updating The Data Store And Set Command Handler Ready For Expiry
Implementing Expire On Read
Implementing Background Expiry
Step 5 - Solution: Implementing Key Expiry (Common Parts)
Step 5 - Solution: Implementing Key Expiry Using Threads
Step 5 - Solution: Implementing Key Expiry Asynchronously
Step 6 - Implementing More Commands

Step 6 - Challenge: Adding More Commands
Impelenting EXISTS and DEL
Implementing INCR and DECR
Implementing LPUSH, RPUSH And LRANGE
Step 6 - Solution: Adding More Commands
Step 7 - Performance

Step 7 - Challenge: Performance Optimisation and Benchmarking
Benchmarking Your Server
How To Optimise For Performance
Performance Tuning The Server
Step 8 - Persistence

Step 8 - Challenge: Persistence
Persisting The Database
Loading The Database
Step 8 - Solution: Persistence
Closing Remarks

The Complete Final Solution
Going Further
Wrapping Up

Step 3 - Challenge: SET and GET

In this step your goal is to set and get the value of a key. You’re going to implement the core functionality of Redis.

To set a key in Redis we use the command SET. For this step we’re just going to implement the simplest version, i.e.:

% redis-cli set Name John
OK

We’ll ignore all the expiry options that Redis supports for now. Once a key has been set you’ll want to implement and test the related command GET.

% redis-cli get Name
"John"

When you are implementing the commands don’t forget to read the specification for each command to check that you are returning the correct results to the client and that the results are correctly serialised according to the RESP protocol.

You might also like to use the Redis client library to build some automated tests for your server.

Don’t forget to test edge/error cases as well as the happy path.