cache

Cache -- Caching Strategy

Activate When

• User invokes /godmode:cache
• User says "add caching", "cache invalidation", "stale data", "cache consistency"
• User says "Redis setup", "Memcached config", "CDN configuration"
• User says "cache stampede", "thundering herd", "hot key"
• When /godmode:perf identifies slow queries or high latency

Workflow

Step 1: Cache Opportunity Assessment

CACHE ASSESSMENT:
Project: <name>
Current Caching: None | CDN only | App-level | Multi-layer
Performance Baseline: P50/P95 latency, Database QPS, Cache hit rate
HOT PATH ANALYSIS: Endpoint, QPS, Latency, Cacheable (Y/N), TTL
IMPACT ESTIMATE: Hit rate, latency reduction, DB load reduction

Step 2: Cache Layer Design

Multi-layer architecture: CDN/Edge -> Application (Redis/Memcached) -> DB Query Cache -> Source of Truth (Database).

Cache-Aside Pattern (Default):

• Read: check cache -> HIT: return | MISS: query DB, store in cache with TTL, return
• Write: write to DB, then delete cache key (not update). Next read repopulates.
• Use when: read-heavy (10:1+), brief staleness OK. Start here.

Step 3: Cache Invalidation Strategies

TTL-Based: TTL = max acceptable staleness. Static config: 24h. Product catalog: 10m. Search results: 1m. Real-time pricing: 10s. Always set a TTL.

Event-Based: On data change, publish event -> consumer deletes cache keys + purges CDN. Near-real-time, precise.

Write-Through: Write to cache AND DB synchronously. Always consistent. Higher write latency.

Write-Behind: Write to cache immediately, async flush to DB. Fast writes. Risk of data loss.

Default recommendation: Cache-aside + TTL + event-based invalidation.

Step 4: Redis Configuration

• Deployment: Standalone (dev), Sentinel (simple HA), Cluster (large/high throughput)
• Memory policy: allkeys-lru (recommended). Set maxmemory.
• Connection pooling: pool_size 20, min_idle 5, connect_timeout 3s, command_timeout 1s
• Key naming: {entity}:{id}, {entity}:{id}:{field}, {entity}:list:{filter}
• All keys MUST have a TTL — use SETEX or SET with EX option