Cache-Topology Architecture: Best Practices¶

Objective: Establish comprehensive multi-tier cache topology patterns that optimize performance, reduce latency, and manage cache hierarchies across edge, application, and data layers. When you need cache topology, when you want multi-tier caching, when you need cache strategy—this guide provides the complete framework.

Introduction¶

Cache topology is fundamental to high-performance systems. Without proper cache hierarchies, systems suffer from latency, database load, and poor user experience. This guide establishes patterns for multi-tier cache topology, cache placement, and cache coherence.

What This Guide Covers: - Multi-tier cache architecture (L1, L2, L3) - Edge caching (CDN, browser) - Application-level caching (in-memory, distributed) - Database caching (query cache, connection pool) - Cache coherence and invalidation - Cache topology patterns - Cache placement strategies

Prerequisites: - Understanding of caching principles - Familiarity with distributed systems - Experience with performance optimization

Related Documents: This document integrates with: - End-to-End Caching Strategy - Caching patterns - System Resilience, Rate Limiting, Concurrency Control & Backpressure - Resilience - Cost-Aware Architecture & Resource-Efficiency Governance - Cost optimization

The Philosophy of Cache Topology¶

Topology Principles¶

Principle 1: Multi-Tier Hierarchy - Edge → Application → Database - Closer to user = faster - Hierarchical invalidation

Principle 2: Cache Coherence - Consistent data - Invalidation strategies - Event-driven updates

Principle 3: Optimal Placement - Right data, right tier - Cost vs performance - Latency optimization

Multi-Tier Cache Architecture¶

Topology Diagram¶

Diagram:

graph TB
    subgraph Edge["Edge Cache"]
        CDN["CDN"]
        Browser["Browser Cache"]
    end

    subgraph Application["Application Cache"]
        InMemory["In-Memory"]
        Redis["Redis"]
    end

    subgraph Database["Database Cache"]
        QueryCache["Query Cache"]
        ConnectionPool["Connection Pool"]
    end

    Edge --> Application
    Application --> Database

    style Edge fill:#fff4e1
    style Application fill:#e1f5ff
    style Database fill:#ffebee

Cache Placement Strategies¶

Placement Rules¶

Pattern:

# Cache placement
cache_placement:
  edge:
    data: "static_assets"
    ttl: "1 year"
  application:
    data: "user_sessions"
    ttl: "1 hour"
  database:
    data: "query_results"
    ttl: "5 minutes"

Architecture Fitness Functions¶

Cache Topology Fitness Function¶

Definition:

# Cache topology fitness function
class CacheTopologyFitnessFunction:
    def evaluate(self, system: System) -> float:
        """Evaluate cache topology"""
        # Check hit rates
        hit_rates = self.check_hit_rates(system)

        # Check latency reduction
        latency_reduction = self.check_latency_reduction(system)

        # Check coherence
        coherence = self.check_cache_coherence(system)

        # Calculate fitness
        fitness = (hit_rates * 0.4) + \
                  (latency_reduction * 0.3) + \
                  (coherence * 0.3)

        return fitness