I've been exploring semantic caching and noticed that it can work well until suddenly it stops, not necessarily due to incorrect similarity but because reuse isn't valid in real-world conditions. I've encountered several examples: responses that seemed semantically close but violated freshness or state assumptions, cache reuse that crossed tenant or policy boundaries, changing rate or budget pressures impacting what reuse was deemed acceptable, and endpoints where correctness degraded without a clear failure. It seems like the real issue isn't about improving embeddings but about establishing explicit reuse constraints such as freshness bounds, risk classes, state dependencies, and budget limits that determine whether reuse is permitted. I'm interested in how others manage these challenges in production environments. Specifically, what calls do you strictly prohibit caching? How do you manage and define allowable staleness? Do changes in rate or cost influence your reuse guidelines? And do you view cache violations as correctness bugs or operational issues?
2 Answers
Semantic caching can definitely fail if you don't account for those reuse constraints. It's crucial to have explicit rules about freshness and validity. If there's a chance that your cached response might be stale or invalid, you likely need to reconsider that caching strategy altogether. In my experience, some APIs I work with simply can't afford any degree of staleness due to their critical nature, especially in financial services.
It's key to balance caching with state awareness! We actively forbid caching on endpoints that change frequently or are sensitive to real-time updates. For less critical data, we define clear staleness limits—like up to 10 minutes—beyond which we refresh the cache. Costs definitely influence our caching strategy—tight budgets make us more cautious with what we keep cached.
That's smart! Have you encountered situations where you wish you'd cached something but the conditions were too risky? It’s all about finding that sweet spot.

Absolutely agree! I've faced similar challenges where permissive caching led to silent data inconsistencies. We only cache responses that are guaranteed to be static or have well-defined update patterns.