In my own understanding:
LVS: It implements load balancing. Customers request lvs through vip, and lvs selects a real-server server to respond through the load scheduler according to the corresponding algorithm, ensuring that if any server goes down, the response can be carried out normally.
keepalived: It is a high-availability software. Its main functions are heartbeat detection and failover. Through the vrrp protocol, when the master node goes down, the vip will drift to the backup node, and then the backup node will take over the application on the master node. At this time, the client can still access the request through VIP and obtain the corresponding page.
keepalived: heartbeat detection: heartbeat detection of the backend real server.
Failover: Drift the failed VIP.