34 lines
1006 B
Markdown
34 lines
1006 B
Markdown
---
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title: "Cache Hit Ratio (CHR)"
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created: 2026-05-11
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updated: 2026-05-11
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type: concept
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tags: [cache, metrics, observability, system-design]
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sources: [[prompt-caching-architecture]]
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---
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# Cache Hit Ratio (CHR，缓存命中率)
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## 定义
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Cache Hit Ratio 是衡量 [[prompt-caching|Prompt Caching]] 效率的核心指标：
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CHR = (缓存命中的请求数) / (总请求数)
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## 工程标准
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- **CHR ≥ 95%**：健康状态，[[prompt-layering|提示分层]] 设计有效
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- **CHR < 95%**：触发告警，需立即排查 [[cache-invalidation|失效原因]]
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- 在 [[meta-jctrader|Meta-JCTrader]] 等高频系统中，低 CHR 直接意味着高额账单损失和不可接受的延迟
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## 辅助指标
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- **Invalidation Point Identification**：失效点的字节偏移追踪
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- **Cost Efficiency Score**：Cache-Off vs Cache-On 的 Token 消耗对比
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## 相关概念
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- [[prompt-caching|Prompt Caching]]
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- [[cache-invalidation|缓存失效]]
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- [[cache-health-observability|缓存健康度可观测性]]
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