Autoscaling an Instance Group with Custom Cloud Monitoring Metrics
Under 'Creating the instance group' the lab guide says '2. Set Autoscaling mode to Don't autoscale'. I missed this the first time I did the lab (which was clearly my mistake) and this lead to resource overprovisioning and ultimately my account being blocked. While your support team was so kind and re-enabled my account, I suggest pointing out in the lab guide that setting the IG to 'Don't autoscale' is a crucial step and missing this can have severe results.
Get the following error message next to the instance group: "The custom metric that was specified does not exist or does not have the necessary labels."