For one my project, I need active-standby loadbalancer in Azure. In the backend, I have two VM instances (primary/secondary manner). Load balancer will send traffic to only one instance (primary). If primary fails, it will send to traffic to secondary instance.
Azure load balancer uses 5 tuple has algorithm based. How can configure it to communicate with the primary and if primary fails, only then to communicate with secondary.
Update: Azure "Traffic Manager" is the solution for distributing traffic in active-standby manner (priority based routing). Relevant links below:
Related links:
https://docs.microsoft.com/en-us/azure/traffic-manager/traffic-manager-how-it-works
https://docs.microsoft.com/en-us/azure/traffic-manager/traffic-manager-routing-methods
Best Answer
Azure load balancer only works on Hash based routing. But you can make use of Azure LB's probe and add intelligence to achieve what you have asked.
You need to make the secondary VM not to respond to the probe that LB sends. Once the Primary fails, then you need to make the Secondary respond to the probe.
You can achieve this using HTTP probe and making secondary to respond as non 200 OK status code to make the probe fail.