Target groups
An L7 load balancer target group is a set of IP addresses of VMs that your network applications are running on. To enable the load balancer to distribute routing requests between the VMs of the target group, specify it in the backend group configuration.
The main targets in a group are VMs connected to Virtual Private Cloud subnets. For your L7 load balancer to run properly, make sure the target subnets are located in the same cloud network.
You can also add to a target group targets residing outside Virtual Private Cloud, e.g., in your data center connected to Yandex Cloud through Cloud Interconnect. The IP addresses of targets must be within the RFC 1918 private ranges. For more information, see Subnets.
You can create target groups:
- Manually. In this case, if you change the VM internal IP address, for example, when moving it to another subnet, make sure to update the target group: first remove the VM and then add the modified VM back to it.
- Using Instance Groups. When you change the VM configuration, Instance Groups automatically updates IP addresses of VMs in the target group. If the target group is connected to a backend group, Instance Groups also monitors health check results delivered by the L7 load balancer.
You cannot delete a target group used in a backend group. First, you need to remove it from all backend groups.
Use cases
- Setting up virtual hosting
- Creating an L7 load balancer with DDoS protection using the management console or CLI
- Migrating services from an external NLB load balancer to an L7 ALB load balancer with an internal NLB load balancer as a target
- Migrating services from a NLB load balancer with an instance group as a target to an L7 ALB load balancer
- Terminating TLS connections using the management console
- Writing load balancer logs to PostgreSQL
- Fault-tolerant website with load balancing via Yandex Application Load Balancer