Binary Lane customers are able to use an HTTP/HTTPS load balancer, for an additional fee of $9.95 per month. The load balancer is fully redundant and configurable through our control panel.


A screenshot of the Load Balancer configuration

Requirements

  • At least two servers - required for high availability
  • Each VPS must be running a web server (for example, Apache or Internet Information Services)
  • Each VPS must serve basically the same content


How it works

After you sign up for the Load Balancer service, you are assigned a new "virtual" IP address, which will become the new IP address of your web site. From the control panel, select the VPSs that HTTP requests will be distributed over - these are referred to as the "real" IPs, and correspond to the actual servers that will handle the requests.


An automated health check is performed every three seconds by the Load Balancer. Each of the real IPs will receive a HTTP request to determine if that server is functioning correctly.


When a new HTTP request is received at the virtual IP, the load balancer selects a healthy real IP and passes the request through. The real server then processes the request and sends a response.


Load Balancer technical information

  • The Load Balancer is non-terminating: packets from each client are passed directly to the server with no modification made to the payload.
  • The Load Balancer performs Layer 2 ("direct") routing: each packet from a client has the destination MAC address altered and then placed back onto the network for the real server to receive.
  • From the real server's perspective, the source IP is still the client - the load balancer is invisible.
  • From the real server's perspective, the destination IP is the virtual IP. For this reason the virtual IP must be added as a secondary address on each of the real servers. Our virtualisation stack will automatically block ARP on the real servers to prevent conflicts.
  • The load balancer has a 60 second timeout on session stickiness (requests from one IP address will continue to be sent to the same real server within the 60 second window). After that point a request may end up on any server in the load balanced pool.