How to Manage Health Checks on a Vultr Load Balancer

Updated on 07 April, 2025

Health Checks on a Vultr Load Balancer monitor the status of your backend servers by periodically sending requests to them. These checks assess whether a server is healthy and responsive, enabling the Load Balancer to route traffic only to servers that are functioning correctly. By configuring health checks, you ensure that traffic is directed away from servers experiencing issues, maintaining the reliability and performance of your application.

Follow this guide to manage the health checks on a Vultr Load Balancer using the Vultr Customer Portal, API, or CLI.

Vultr Customer Portal
Vultr API
Vultr CLI

Navigate to Products and click Load Balancers.
Click your target Load Balancer to open its management page.
Click Configuration.
Click Health Checks in the left navigation menu.
Click the Protocol drop-down and select the target protocol from the list of options.
- HTTP: Perfoms health checks using the Hypertext Transfer Protocol (HTTP).
- HTTPS: Perfoms health checks using the Hypertext Transfer Protocol Secure (HTTPS).
- TCP: Perfoms health checks using the Transmission Control Protocol (TCP).
Enter the target port in the Port field to monitor.
Set the Interval in seconds to perform health checks on the target port.
Set the Response timeout in seconds for how long the Load Balancer should wait between responses on the target port.
Set the Unhealthy Threshold to define how many times an instance should fail before the Load Balancer stops forwarding traffic.
Set the Healthy Threshold to define how many times an instance should pass before the Load Balancer starts forwarding traffic to it.
Enter the URL path in the HTTP Path field to perform healthy checks.
Click Save changes to apply the changes.

Send a GET request to the List Load Balancers endpoint and note the target Load Balancer's ID.

                            console
                            
                        
$ curl "https://api.vultr.com/v2/load-balancers" \
    -X GET \
    -H "Authorization: Bearer ${VULTR_API_KEY}"

Send a PATCH request to the Update Load Balancer endpoint to update the target Load Balancer's health checks configuration.

                            console
                            
                        
$ curl "https://api.vultr.com/v2/load-balancers/{load-balancer-id}" \
    -X PATCH \
    -H "Authorization: Bearer ${VULTR_API_KEY}" \
    -H "Content-Type: application/json" \
    --data '{
        "health_check" : {
            "protocol" : "{http_or_https_or_tcp}",
            "port" : {port},
            "path" : "{path}",
            "check_interval" : {interval_in_seconds},
            "response_timeout" : {timeout_in_seconds},
            "unhealthy_threshold" : {unhealthy_threshold},
            "healthy_threshold" : {healthy_threshold}
        }
    }'

Send a GET request to the Get Load Balancer endpoint to fetch the details of the target Load Balancer.

                            console
                            
                        
$ curl "https://api.vultr.com/v2/load-balancers/{load-balancer-id}" \
    -X GET \
    -H "Authorization: Bearer ${VULTR_API_KEY}"

List all available instances and note the target Load Balancer's ID.
console
```
$ vultr-cli load-balancer list
```

Update the target Load Balancer's health checks configuration.

                            console
                            
                        
$ vultr-cli load-balancer update <load-balancer-id> \
    --protocol "<http_or_https_or_tcp>" \
    --port {port} \
    --path "{path}" \
    --check-interval <interval_in_seconds> \
    --response-timeout <timeout_in_seconds> \
    --healthy-threshold <healthy_threshold> \
    --unhealthy-threshold <unhealthy_threshold>