Resources

Part 0, Setup

• Adoptium Temurin, JDK builds for every platform
• SDKMAN, the least painful way to run several JDKs
• Maven downloads
• Maven in 5 minutes
• IntelliJ IDEA Community
• VS Code Extension Pack for Java
• WSL install guide, Windows readers
• Redis downloads, for redis-cli

Part 1, TCP and sockets

• ServerSocket Javadoc
• Socket Javadoc
• Oracle: All About Sockets, the official Java networking trail
• Beej’s Guide to Network Programming, C, but the best plain-English explanation of what sockets are
• RFC 9293, TCP, the specification itself
• Computerphile: How the Internet Works / TCP, video, good background
• Baeldung: A Guide to Java Sockets, worked examples

Part 2, Framing and concurrency

• JEP 444: Virtual Threads, the proposal, readable and worth it
• Oracle: Virtual Threads guide
• Thread Javadoc
• Nagle’s algorithm, why your two writes arrived as one packet

Part 3, RESP

• Redis serialization protocol specification, the primary source, read it once end to end
• RESP2 in redis-specifications
• StandardCharsets Javadoc

Part 5, Storage and time

• ConcurrentHashMap Javadoc, read the class-level notes on atomicity
• Redis key expiry docs
• System.nanoTime Javadoc, states plainly that it is monotonic and has no relation to wall time

Part 6, Atomicity

• Redis INCR
• Redis lists
• Java Memory Model / java.util.concurrent package docs

Part 7, Blocking and transactions

• Redis transactions, explains why there is no rollback, from the source
• Redis BLPOP
• Object.wait Javadoc, the spurious-wakeup paragraph is the one that matters

Part 8, Pub/sub and streams

• Redis pub/sub
• Redis streams introduction

Part 9, More types

• Redis sorted sets
• Redis SCAN, the guarantees section explains why a key can appear twice
• Skip lists (Pugh, 1990), what real Redis uses instead of a TreeMap

Part 10, Persistence

• Redis persistence
• RDB file format, annotated, the community reference everyone uses
• LZF compression, what we refuse to decode

Part 11, Replication

• Redis replication
• Redis PSYNC / replication internals

Comparable series, worth reading alongside

• Build Your Own Redis with C/C++, same project in a different language, especially good on data structures
• Coding Challenges: Build Your Own Redis
• CodeCrafters Redis track, test-driven, if you want a harness grading you
• Build Your Own X, the wider genre