🗄️ Database Administration — Redis Patterns Library Demo

• **Atomic Lua scripts** you can `EVAL` directly (rate limiter, sliding window,
• **`redis-cli` walkthroughs** (`scripts/*.sh`) that you can paste line by line to
• **Dependency-free Python** (`examples/*.py`) built on a tiny RESP client that
• An **annotated `redis.conf`** that explains *why* each tuning knob matters, not
• **Redis 6.2+** (7.x recommended). Streams require 5.0+, `GETDEL` requires 6.2+,
• **`redis-cli`** on your `PATH` for the shell walkthroughs.

# 1. Point at your Redis (defaults shown)
export REDIS_HOST=127.0.0.1
export REDIS_PORT=6379

# 2. Load the annotated config (optional, for a local test server)
redis-server config/redis.conf

# 3. Watch a pattern behave, line by line
bash scripts/cache_aside_demo.sh
bash scripts/leaderboard_demo.sh
bash scripts/streams_consumer_group.sh

# 4. Run an atomic Lua script straight from the file
redis-cli --eval lua/sliding_window.lua ratelimit:user:42 , "$(date +%s%3N)" 60000 5 "req-$RANDOM"

# 5. Run the dependency-free Python examples
python3 examples/rate_limiter.py
python3 examples/distributed_lock.py

redis-patterns-library/
├── README.md                         This file
├── LICENSE                           MIT
├── config/
│   └── redis.conf                    Annotated tuning: memory, eviction, persistence, latency
├── docs/
│   ├── caching-strategies.md         Cache-aside, read-through, write-through, write-behind, stampede control
│   ├── rate-limiting.md              Fixed window, sliding window, token bucket, leaky bucket — trade-offs + Lua
│   ├── distributed-locks.md          SET NX PX, fencing tokens, safe release, Redlock caveats
│   ├── pubsub-and-streams.md         Pub/sub vs Streams, consumer groups, claiming, dead-letter handling
│   ├── leaderboards-and-sorted-sets.md  Ranking, pagination, ties, time-decay, top-N
│   └── ttl-and-eviction.md           TTL hygiene, eviction policies, memory accounting, OOM debugging
├── lua/
│   ├── token_bucket.lua              Atomic token-bucket rate limiter
│   ├── sliding_window.lua            Atomic sliding-window-log rate limiter
│   ├── acquire_lock.lua              Atomic lock acquire with monotonic fencing token
│   └── release_lock.lua              Owner-checked safe release
├── scripts/
│   ├── cache_aside_demo.sh           Cache-aside hit/miss/invalidate walkthrough
│   ├── leaderboard_demo.sh           Sorted-set leaderboard: rank, range, pagination
│   └── streams_consumer_group.sh     XADD / XREADGROUP / XACK / XAUTOCLAIM end to end
└── examples/
    ├── redis_client.py               Minimal stdlib-only RESP client (socket-level)
    ├── rate_limiter.py               Token-bucket limiter calling the Lua script via EVAL
    ├── distributed_lock.py           Context-manager lock with fencing token + safe release
    └── sample_data.redis             Seed data for the leaderboard / cache demos