Google Application Load Balancer - backend instance-group VM marked unhealthy alert

[tacoma50]

I have an external global application Load Balancer running. The LBs backend service has an instance group with 2 VM servers it. Everything works great. As expected, when I stop the http server on one of the VM's, the backend service eventually shows that only 1 of 2 the VMs in the instance groups are healthy.

My questions are:
1. Where can I see the date and time the VM was marked unhealthy.
2. How can I receive an alert when a server in an instance group is marked unhealthy by LB.

[FrancoGP · Accepted solution]

Hi @tacoma50 ,

Welcome to Google Cloud Community!

For both of your questions I would recommend the same path, enable cloud logging over your health checks and utilize them to trigger log based alerting  to let you know the change of status

With that solution in place you'll have a specific timestamp to rely and the monitoring that you are seeking

[tacoma50]

Hi @FrancoGP 
Thank you that worked!
I did create another post related to this topic, because your solution worked in one of my projects but I can't get logging to work in another project the same way. See here: 
https://www.googlecloudcommunity.com/gc/Infrastructure-Compute-Storage/Google-Cloud-LB-healthcheck-l...