You can save on costs by creating a machine set running on GCP that deploys machines as non-guaranteed preemptible VM instances. Preemptible VM instances utilize excess Compute Engine capacity and are less expensive than normal instances. You can use preemptible VM instances for workloads that can tolerate interruptions, such as batch or stateless, horizontally scalable workloads.
GCP Compute Engine can terminate a preemptible VM instance at any time. Compute Engine sends a preemption notice to the user indicating that an interruption will occur in 30 seconds. OKD begins to remove the workloads from the affected instances when Compute Engine issues the preemption notice. An ACPI G3 Mechanical Off signal is sent to the operating system after 30 seconds if the instance is not stopped. The preemptible VM instance is then transitioned to a TERMINATED
state by Compute Engine.
Interruptions can occur when using preemptible VM instances for the following reasons:
-
There is a system or maintenance event
-
The supply of preemptible VM instances decreases
-
The instance reaches the end of the allotted 24-hour period for preemptible VM instances
When GCP terminates an instance, a termination handler running on the preemptible VM instance node deletes the machine resource. To satisfy the machine set replicas
quantity, the machine set creates a machine that requests a preemptible VM instance.