Load balancers distribute traffic across app servers.
Common strategies:
- Round-robin: simple, good for equal-weight servers.
- Least-connections: better for uneven load per connection.
- IP-hash / sticky sessions: required if session state is stored locally (avoid when possible).
Prefer stateless services + centralized session store (Redis) and avoid sticky sessions.
Mini-checklist:
- Start with round-robin or cloud-managed LB.
- Centralize session/state if you need active-active scaling.
- Monitor connection distribution and tail latency.
No code needed — configuration is on the infra side (NGINX, HAProxy, cloud LB).