Database sering menjadi bottleneck saat sistem berkembang. Scaling melibatkan teknik seperti replikasi (salinan untuk read scaling dan ketersediaan), sharding (membagi data di beberapa server), caching, dan memilih tipe database yang sesuai.
Replikasi — salinan data
REPLICATION → maintain COPIES of the database across servers:
→ PRIMARY (writes) + REPLICAS (copies):
- READ SCALING → direct reads to replicas (offload the primary) → handle more reads
- AVAILABILITY → a replica can take over if the primary fails (failover)
⚠️ replication lag → replicas may be slightly behind (eventual consistency for reads)
→ great for READ-heavy workloads and availability (most apps are read-heavy)
