Health check probes come from addresses in the ranges 130.211.0.0/22 and 35.191.0.0/16. HTTP(S) Load Balancer uses health checks to determine if a particular backend instance should receive traffic. If all are unhealthy, clients receive message of “no healthy upstream” Managed Instance Groups also use health checks, but for a different purpose. If an instance is reported an unhealthy, it will…

Group of VMs with different configurations. Use case: Lift and shift of on-premise workloads that need a load balancer to serve traffic. No automatic elasticity or automatic healing

It is up to you what you want to put into the connectivity VPC Connectivity VPC : transit VPC + CI/CD …

https://medium.com/google-cloud/using-a-multi-nic-vm-to-connect-vpcs-in-google-cloud-d84aa533538

An SLI is a service level indicator—a carefully defined quantitative measure of some aspect of the level of service that is provided. Most services consider request latency—how long it takes to return a response to a request—as a key SLI. Other common SLIs include the error rate, often expressed as a fraction of all requests received, and system throughput,…