# Redis Scaling

> Scale Redis with Sentinel vs Cluster, hash tags, hot-key mitigation, pipelining, pooling, and maxmemory policies. Use when Redis is a bottleneck or planning cluster migration.

- Skill: `deangrant/redis-scaling` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add deangrant/redis-scaling`
- Raw SKILL.md: https://api.skillmd.com/api/skills/deangrant/redis-scaling/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: deangrant (https://skillmd.com/u/deangrant)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/deangrant/redis-scaling

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# Redis Scaling

Use this skill when Redis must sustain **high throughput or large memory**.

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## 1. Topology

Start Sentinel + single primary until ~100k ops/s or ~25 GB. Move to **Cluster**
when throughput/RAM limits hit. Plan **hash tags** for multi-key ops. Prefer
latency-aware replica reads when available.

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## 2. Hot keys

Monitor per-shard CPU. Read-heavy → short in-process LRU. Writable hot keys →
N-way key replication across slots. At scale → client-side caching / BCAST.

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## 3. Throughput and memory

Pipeline batch reads (slot-grouped in Cluster). Size pools by
`conns_per_pod × pods`; stagger restarts; fail-fast timeouts.
`maxmemory` ≈ 50% RAM; `allkeys-lru` (cache) or `volatile-lru` (mixed). Target
hit rate >95%; watch `evicted_keys`; replication lag low.

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## 4. Quick checklist

- [ ] Sentinel vs Cluster decision explicit.
- [ ] Hash tags planned for multi-key.
- [ ] Hot-key mitigations.
- [ ] Pipelining + pooled clients + timeouts.
- [ ] maxmemory policy set.

See [reference.md](reference.md) and [examples.md](examples.md).