Preemptible instances in Oracle Cloud Infrastructure (OCI) provide users with an opportunity to access computing capacity at a discounted rate. However, there are important considerations to understand before utilizing them for your workloads.
What are Preemptible Instances?
Preemptible instances are similar to on-demand instances, but with one crucial difference. OCI reserves the right to terminate preemptible instances if compute capacity is needed elsewhere. This termination can occur at any time, making preemptible instances unsuitable for long-term or mission-critical workloads.
Benefits of Preemptible Instances
Despite their potential for termination, preemptible instances offer significant cost savings, being offered at a 50% discount compared to on-demand instances. They utilize unused on-demand capacity, allowing OCI to provide them at a reduced rate.
Use Cases for Preemptible Instances
Preemptible instances are ideal for short-term, non-critical workloads. For example, batch jobs such as video encoding can benefit from the cost savings of preemptible instances, where the termination risk is mitigated by the transient nature of the task.
Limitations and Considerations
It’s important to note that preemptible instances have limitations. You cannot modify the instance shape after launch or convert them to on-demand instances. Additionally, preemptible capacity does not support bare-metal instances and cannot be used in instance pools.
Managing Preemptible Instances
Creating preemptible instances in OCI follows the same process as on-demand instances through the management console. Users can select preemptible capacity in the placement section during instance creation, enabling access to discounted compute resources.
Termination Notices
OCI provides users with a termination notice through the event service before preemptible instances are terminated. This notification allows users to prepare for potential instance termination and take necessary actions.
Conclusion
Preemptible instances offer significant cost savings for short-term workloads, albeit with the risk of termination by OCI. Understanding their limitations and use cases is essential for effectively leveraging preemptible instances within your cloud infrastructure. In the next lesson, we will explore a demonstration of creating preemptible instances in OCI.