Building a Million‑Request Load‑Balancing Architecture with LVS, Nginx, and Keepalived

In scenarios requiring million‑level concurrent requests, a single server cannot bear the massive traffic, so a robust, highly available load‑balancing architecture is essential.

A classic and efficient solution combines LVS, Nginx, and Keepalived, addressing high concurrency, traffic distribution, and fault tolerance.

LVS operates at layer 4, handling massive TCP connections (e.g., tens of thousands per second) with low overhead, acting as the front‑line distributor that spreads requests evenly to a backend Nginx cluster, preventing individual Nginx nodes from being overwhelmed.

Nginx receives traffic forwarded by LVS and performs intelligent HTTP‑level load balancing based on request headers, URLs, etc. Multiple Nginx instances can be horizontally scaled, each optionally using Keepalived for VIP management or DNS/service discovery for traffic scheduling.

Keepalived monitors the health of LVS and Nginx, enabling automatic master‑backup failover. The LVS master binds a VIP to receive all user requests; Keepalived watches both master and standby nodes, and if the master fails, it instantly triggers a failover to maintain service continuity.

Overall, the LVS + Nginx + Keepalived combination provides a cost‑effective, mature, and stable solution for high‑concurrency and high‑availability scenarios.