BackendReel #34 · 4 Nov 2026

App viral, server down: bada server ya load balancer?

Vertical scaling: ek machine ko bada karna (zyada CPU/RAM); simple, par hardware limit aur single point of failure. Horizontal scaling: kai machines ke aage load balancer jo requests baant de (round robin, least connections); app stateless honi chahiye (sessions shared store mein), aur database alag se scale karna padta hai. Overload par server 503 Service Unavailable de sakta hai. Asli systems aksar dono mix karte hain.

Links

nginx: HTTP load balancing round robin, least_conn, ip_hash

MDN: 503 Service Unavailable server overload ka status code

Aaj ye karo

Pehle naapo: CPU, memory aur response time kahan atak raha hai.
Jaldi rahat chahiye toh vertical: instance size badhao.
Lambi race ke liye horizontal: app ko stateless banao, sessions Redis jaise shared store mein.
Phir nginx ya cloud load balancer se 2+ servers ke aage traffic baanto.

upstream app { server 10.0.0.11; server 10.0.0.12; }

location / { proxy_pass http://app; }

Sources

nginx docs, MDN Web Docs; 4 Nov 2026 ko check kiya.