You can use Azure Traffic Manager to failover from a primary load balancer to a secondary load balancer. Here are the general steps to set up Traffic Manager for failover:
- Create two Azure Load Balancer instances, one for the primary load balancer and one for the secondary load balancer.
- Create an Azure Traffic Manager profile, and configure it to use the "Performance" routing method.
- Add the primary load balancer as the first endpoint to the Traffic Manager profile.
- Add the secondary load balancer as the second endpoint to the Traffic Manager profile.
- Configure the endpoint monitoring for both the primary and secondary load balancers.
- Configure the endpoint status to "Enabled" for the primary load balancer and to "Disabled" for the secondary load balancer.
- Test the failover by shutting down the primary load balancer or by simulating an outage.
- Once the failover is working as expected, you can configure the DNS settings to point to the Traffic Manager endpoint.
When the primary load balancer is healthy and available, Traffic Manager will route the traffic to the primary load balancer, and when it becomes unavailable, Traffic Manager will automatically route the traffic to the secondary load balancer.
It's important to note that there may be a small amount of downtime during the failover process, as the traffic is being routed to the secondary load balancer.
Also you can use "Failover" routing method instead of "Performance" routing method, In this case you can configure the primary endpoint as the active endpoint and the secondary endpoint as the standby endpoint. This allows you to test the failover by simulating a failure on the active endpoint.
It's important to keep monitoring the load balancers and traffic manager to ensure that they are working as expected, and to troubleshoot any issues that may arise.