RAG (Retrieval-Augmented Generation) Production Architecture

System Overview

End-to-end RAG system with vector database, caching, monitoring, and scaling capabilities for production workloads.

📊 Architecture Diagram: User Request → API Gateway → Cache Layer → Vector DB Query → LLM Inference → Response

API Gateway

FastAPI with rate limiting, authentication, and request validation

Cache Layer

Redis for semantic caching and frequent query results

Vector Database

Pinecone or Weaviate for embedding storage and similarity search

LLM Inference

vLLM or TensorRT-LLM for high-throughput generation

Monitoring

Prometheus + Grafana for metrics, Langfuse for LLM observability

Load Balancer

NGINX or AWS ALB for traffic distribution

Best Practices

  • Implement semantic caching to reduce LLM calls by 40-60%
  • Use hybrid search (vector + keyword) for better retrieval accuracy
  • Set up query rewriting to improve vector search relevance
  • Monitor retrieval quality with precision and recall metrics
  • Implement circuit breakers for LLM API failures
  • Use async processing for non-critical requests

Blue-Green Deployment for ML Models

Standard Operating Procedure

1

Prepare Green Environment

Deploy new model version to green environment (separate from production blue)

kubectl apply -f model-deployment-green.yaml kubectl wait --for=condition=ready pod -l version=green
2

Run Validation Tests

Execute automated tests against green environment: performance, accuracy, and integration tests

python run_validation.py --env=green --threshold=0.95 # Check latency, throughput, and model accuracy
3

Canary Testing

Route 5-10% of traffic to green environment and monitor for anomalies

# Update service to route 10% traffic to green kubectl patch service model-service --type=merge \ -p '{"spec":{"selector":{"version":"green"},"weight":10}}'
4

Monitor Metrics

Track error rates, latency p95/p99, and business metrics for 15-30 minutes

  • Error rate should be < 0.5%
  • P95 latency within 10% of blue
  • No alerts or anomalies detected
5

Full Traffic Switch

If canary successful, route 100% traffic to green; otherwise rollback to blue

# Success: Switch all traffic kubectl patch service model-service --type=merge \ -p '{"spec":{"selector":{"version":"green"}}}' # Rollback if issues detected kubectl patch service model-service --type=merge \ -p '{"spec":{"selector":{"version":"blue"}}}'
6

Decommission Old Environment

After 24-48 hours of stable operation, scale down blue environment

kubectl scale deployment model-blue --replicas=0 # Keep for 7 days before full deletion for emergency rollback

Rollback Procedure

  • Immediately switch traffic back to blue if error rate exceeds threshold
  • Maintain blue environment for minimum 48 hours post-deployment
  • Document all deployment changes and rollback triggers
  • Set up automated rollback on critical metric degradation
  • Test rollback procedure monthly to ensure readiness

Data Quality Monitoring Architecture

Continuous Data Quality Framework

Automated monitoring and alerting for data pipelines with anomaly detection and root cause analysis.

Schema Validation

Great Expectations for schema enforcement and data type validation

Freshness Checks

Monitor data arrival times and detect delays or missing data

Volume Anomalies

Statistical process control for row count variations

Distribution Drift

Kolmogorov-Smirnov tests for detecting distribution changes

Null Rate Tracking

Monitor null percentages across critical columns

Alert Routing

PagerDuty or Slack integration with severity-based escalation

Example Quality Checks

# Great Expectations suite example expectation_suite = { "expectations": [ { "expectation_type": "expect_column_values_to_not_be_null", "column": "user_id", "threshold": 0.99 }, { "expectation_type": "expect_table_row_count_to_be_between", "min_value": 900000, "max_value": 1100000 }, { "expectation_type": "expect_column_values_to_be_in_set", "column": "status", "value_set": ["active", "inactive", "pending"] } ] }

Multi-Region ML Deployment

Global Low-Latency Inference Architecture

Distributed model serving across multiple regions with geo-routing and data synchronization.

🌍 Multi-Region Setup: Users → CloudFront/CloudFlare → Regional API Gateways → Regional Model Deployments → Shared Vector DB

Key Considerations

  • Deploy models in regions closest to user base (US-East, EU-West, AP-Southeast)
  • Use CDN for caching responses and static assets
  • Replicate vector databases across regions with eventual consistency
  • Implement geo-routing at DNS level for automatic region selection
  • Monitor cross-region latency and failover health checks
  • Use global load balancer for automatic failover between regions
  • Sync model versions across regions to ensure consistency

Cost Optimization

Multi-region deployments increase costs by 2-3x. Start with single region, then expand based on user distribution and latency requirements. Use spot instances for batch inference workloads to reduce costs by 60-70%.