Billing, Discounts & keeping costs low on GCP.

sustained use discounts:

Google will provide you sustained discounts in case if the virtual instance is running more than 25% of the month.
Sustained discounts are automatically applied usually the discount is between 20-50% on every incremental minute.
The sustained use discounts do not apply for certain machine types like E2 & A2
The sustained use discounts do not also apply if the Virtual instances are created by App Engine or Data flow.

You can get up to 70% discount for committed use of 1 to 3 years.
This is recommended for workloads with predictable needs.
This is applicable for instances created by App Engine or Kubernetes Engine.
This does not apply for Virtual instances created by App Engine flexible or Data flow.
Below is screen shot where you can find the committed discount option.

These are short lived instances that typically run for less than 24 hours.
Instances can be stopped by Google anytime with just a 30 second warning.
The good example when we can use these is if we need a cheap resource & with no need for any SLA and the application in our requirement is extremely fault tolerant.
Spot instances are also called spot instances and when creating a VM you can find them under availability policy.

For compute engines you are billed by the second after a minimum of 1 minute
You are not billed for compute when the virtual instance is stopped
When the compute instance is stopped you are still charged for the storage attached to it and any static IP address that is attached to that virtual instance.
You should ideally create a budget alert that Email’s billing details to the admin when a certain amount exceeds.
Navigate to Billing & then click on Budget and alerts where you can create a budget.

When the target budget is about to exceed the administrator will receive an Email notification.
You can also do a billing export and run queries on it about which we will discuss later.