High Availability & Scalability Patterns

Bu bölüm, yüksek erişilebilirlik (HA) ve ölçeklenebilirlik için kullanılan mimari desenleri, teknikleri ve best practices’i kapsar.

1. High Availability (HA) Nedir?

• Single point of failure (SPOF) önleme
• Redundancy, failover, active-active vs active-passive

2. Load Balancing

• Layer 4 (TCP) ve Layer 7 (HTTP) load balancing
• Round robin, least connections, weighted load balancing
• Global load balancing, DNS-based routing

3. Replication ve Partitioning

• Database replication (master-slave, master-master)
• Data partitioning/sharding, horizontal vs vertical scaling

4. Autoscaling ve Elasticity

• Horizontal ve vertical autoscaling
• Metrics-based scaling, predictive scaling

5. Disaster Recovery ve Backup

• RPO (Recovery Point Objective), RTO (Recovery Time Objective)
• Backup, snapshot, geo-replication, failover testing

6. CAP Teoremi ve Trade-off’lar

• Consistency, availability, partition tolerance
• Eventual consistency, strong consistency, quorum

7. Monitoring ve Health Checks

• Heartbeat, health endpoint, readiness/liveness probes
• Alerting, incident response, self-healing

8. Best Practices ve Sık Karşılaşılan Sorunlar

• Split-brain, network partition, failover loop
• Cost vs availability, over-provisioning, under-provisioning

Her başlık altında örnekler, mimari diyagramlar ve ileri seviye detaylar için ilgili alt bölümlere göz atabilirsiniz.