1Z0-1072-25 Question 23
Select 3You have set up an OCI instance pool with an autoscaling policy to scale up or down based on CPU usage. You verify that scaling up triggers correctly when CPU usage exceeds your defined threshold. However, you notice that the pool does not scale down even though CPU usage returns to normal. Which three steps must you verify to ensure your autoscaling policy is correctly configured to scale down as expected?
- A
Verify that the scale-out increment is lower than the instance pool� maximum size limit.
- B
Confirm that a cool-down period is configured so the policy can reevaluate CPU usage and initiate scale-in.
- C
Ensure that the scale-in threshold is set lower than the scale-out threshold to allow for a proper trigger to reduce instances.
- D
Add a second autoscaling policy based on memory usage instead of CPU usage.
- E
Confirm that the instance pool� minimum size allows the number of instances to decrease below the scale-up count.
Show answer and explanation
Correct answers: B, C, E
Explanation
In OCI, autoscaling policies for instance pools depend on thresholds, minimum/maximum size settings, and cool-down periods. You must configure each element correctly to allow the system to scale out when demand is high and scale in when demand subsides. Specifically: (a) a cool-down period ensures there� enough time to evaluate CPU metrics before adding or removing instances, (b) the scale-in threshold needs to be lower than the scale-out threshold so the system can perceive a real drop in CPU usage, and (c) the minimum size of the instance pool must allow the pool to remove instances below the peak count. Refer to Oracle� official documentation for best practices on threshold-based autoscaling (e.g., OCI Documentation > Compute > Using Autoscaling).
- A. Incorrect.
Option 1 is incorrect. While it is good to confirm that your scale-out increment won't exceed the pool's max size, this alone doesn�t explain why instances never scale down. The maximum limit primarily affects how high the pool can grow.
- B. Correct.
Option 2 is correct. A properly configured cool-down period prevents immediate fluctuation of instance count and gives the autoscaling policy time to reevaluate CPU usage before scaling in.
- C. Correct.
Option 3 is correct. If the scale-in threshold is equal to or higher than the scale-out threshold, the system may never trigger a scale-in. Setting a clearly lower threshold ensures that the policy can recognize reduced resource use and scale down.
- D. Incorrect.
Option 4 is incorrect. Adding a second policy for memory usage does not address the core issue of why CPU-based scaling down fails. While it might be helpful to monitor multiple metrics, it doesn�t resolve a misconfiguration in the existing CPU-based scaling policy.
- E. Correct.
Option 5 is correct. If the minimum size is set too high, the instance pool will not reduce the count below that minimum even when CPU usage drops. Ensuring the minimum size aligns with expected baseline demand is essential for proper scale-in.