Health probe is one of the most useful and significant supported features for load balancers. With it, you can monitor the health of the VMs. So, if a VM goes down or is not reachable for any reason, the traffic will not be forwarded to the unhealthy VM, and get redistributed across other VMs.
To configure the health probes, you need to follow these steps:
- Navigate to the load balancer; under SETTINGS, click on Health probes, and a new blade will be opened, as shown in the following screenshot:
Figure 6.14: Health probes
- Click on Add to add a new health probe to the load balancer, and a new blade will be opened, asking you to specify the following:
- Name: Specify a descriptive name for the probe
- Protocol: Specify whether it is HTTP or TCP
- Path: If HTTP is selected as a protocol, you will have to specify the URI used for requesting the health status from the backend endpoint
- Port: The port through which the probe will check the VM availability
- Interval: The amount of time between probe attempts
- Unhealthy thresholds: The number of consecutive probe failures that must occur before a virtual machine is considered unhealthy:
Figure 6.15: Add a health probe
- Once you have clicked on OK, the health probe will be added