redis-strings

name	redis-strings
description	Master Redis Strings - SET, GET, INCR, DECR, atomic counters, binary-safe operations, and caching patterns
sasmp_version	1.3.0
bonded_agent	02-redis-data-structures
bond_type	PRIMARY_BOND
version	2.1.0
last_updated	2025-01
parameters	{"key":{"type":"string","required":true,"pattern":"^[a-zA-Z0-9:_-]+$","max_length":512},"value":{"type":"string","required":true,"max_size":"512MB"},"ttl_seconds":{"type":"integer","required":false,"min":1,"max":31536000},"nx_xx":{"type":"string","required":false,"enum":["NX","XX"],"description":"NX=only if not exists, XX=only if exists"}}
retry_config	{"max_retries":3,"backoff_strategy":"exponential","backoff_base_ms":100,"retryable_errors":["connection_timeout","BUSY"]}
observability	{"logging":{"level":"debug","include_key_pattern":true},"metrics":["operation_latency_ms","cache_hit_ratio","key_size_bytes"]}
validation	{"key_naming":{"pattern":"object:id:field","examples":["user:123:profile","cache:api:users"]},"value_limits":{"warn_size_kb":100,"max_size_kb":10240}}

Redis Strings Skill

Overview

Production-grade String operations for Redis. Master atomic counters, caching patterns, and binary-safe string manipulation.

Core Commands

Basic Operations

SET key value [EX seconds] [PX milliseconds] [NX|XX] [KEEPTTL]
GET key
GETEX key [EX seconds|PX ms|EXAT ts|PXAT ts|PERSIST]  # Get + set TTL
DEL key [key ...]
EXISTS key [key ...]

Atomic Counters

INCR key                      # +1 (creates if missing, starts at 0)
DECR key                      # -1
INCRBY key increment          # +N
DECRBY key decrement          # -N
INCRBYFLOAT key increment     # Float increment

String Manipulation

APPEND key value              # Append to value
STRLEN key                    # Get length
GETRANGE key start end        # Substring (0-indexed, inclusive)
SETRANGE key offset value     # Replace from offset

Batch Operations

MSET key value [key value ...]      # Set multiple
MGET key [key ...]                  # Get multiple
MSETNX key value [key value ...]    # Set multiple if none exist

Advanced Options (Redis 6.2+)

SET key value GET                   # Set and return old value
SET key value IFEQ oldvalue         # Set if current equals (Redis 7.4+)
GETDEL key                          # Get and delete
SETEX key seconds value             # Set with TTL (deprecated, use SET EX)

Production Patterns

Pattern 1: Cache with TTL

# Set with 1-hour TTL
SET cache:user:123 '{"name":"John","email":"[e-mail]"}' EX 3600

# Get (returns nil if expired)
GET cache:user:123

# Refresh TTL on access
GETEX cache:user:123 EX 3600

Pattern 2: Rate Limiter (Fixed Window)

# Increment counter, set TTL on first request
INCR ratelimit:user:123:minute
EXPIRE ratelimit:user:123:minute 60 NX

# Check count
GET ratelimit:user:123:minute

Pattern 3: Distributed Lock

# Acquire lock (NX = only if not exists)
SET lock:resource:123 "holder-uuid" NX EX 30

# Release lock (only if we own it) - use Lua
EVAL "if redis.call('get',KEYS[1])==ARGV[1] then return redis.call('del',KEYS[1]) else return 0 end" 1 lock:resource:123 "holder-uuid"

Pattern 4: Session Storage

# Create session
SET session:abc123 '{"user_id":1,"created":1704067200}' EX 86400

# Touch session (reset TTL)
GETEX session:abc123 EX 86400

# Invalidate session
DEL session:abc123