Overview of load balancers

Google Distributed Cloud supports two load balancer options: bundled and manual.

Bundled load balancer mode

If you choose bundled load balancing, the load balancer is provided for you. An external load balancer is not needed.

There are two types of bundled load balancing:

  • Layer 2: All load balancer nodes and VIPs must be in the same Layer 2 subnet. The gateway of the load balancer subnet must listen to gratuitous ARP messages and forward ARP packets to the load balancer nodes. See Bundled load balancing with MetalLB.

  • BGP: This load-balancing mode supports the advertisement of ServiceType LoadBalancer virtual IP addresses (VIPs) through external Border Gateway Protocol (eBGP) for your clusters. Your cluster network is an autonomous system, which interconnects with another autonomous system, an external network, through peering. See Bundled load balancing with BGP.

The following diagram shows an example network topology where bundled MetalLB load balancers are located on the control plane nodes.

A diagram showing bundled load balancers located on the name nodes as the control plane. The nodes are in a L2 subnet

Manual load balancer mode

If you choose manual load balancing, Google Distributed Cloud does not deploy load balancers. This allows more flexibility than bundled load balancing and there are no L2 network requirements.

You must configure your control plane nodes' VIPs on an external load balancer before installing the cluster. After installation, you must pick a load balancing solution for Kubernetes Services and Ingresses.

The following diagram shows an example network topology of a cluster using manual load balancing mode with an external load balancer.

A diagram showing bundled load balancing mode with an external load balancer outside of the cluster.