DigitalOcean Load Balancers are a fully-managed, highly available network load balancing service. Load balancers distribute traffic to groups of Droplets, which decouples the overall health of a backend service from the health of a single server to ensure that your services stay online.
The DigitalOcean API lets you manage DigitalOcean resources programmatically using conventional HTTP requests. All the functionality available in the DigitalOcean Control Panel is also available through the API.
See the API documentation on load balancers for more information.
doctl is a command-line interface for the DigitalOcean API and supports many of the same actions.
doctl documentation on load balancers for more information.
If you enable PROXY protocol on a load balancer but the services on the backend Droplets aren't configured to accept PROXY protocol headers, those Droplets will give a 400 response to the load balancer's health checks. This means the load balancer will consider them unhealthy and will stop routing traffic to them.
How you enable PROXY protocol support on your Droplets depends on the software you're running. Here are some resources for common services: