keepalived

Notes:

  • lb_algo determines which real server gets to serve a request, and possible algorithms include round-robin (weighted or not), least-connections (weighted or not), etc (see RHEL docs).
  • lb_kind determines how the real server receives the request, and the supported methods on RHEL 7 are NAT and DR.

lb_kind DR

Notes:

  • The load balancers and the real servers need to be on the same network segment
  • The Virtual IP is configured on all real servers, and real servers need to be configured to ignore ARP requests for the virtual IP. This can be achieved with either arptables, or iptables or sysctl configuration.

See also