Exam AZ-301 topic 4 question 9 discussion

Tested this in a lab with 5 min cool down and 10 min measure. It was scaled up and then scaled up a second time after 5 min. So for me, the answer would be 10 min.

The cool down period occurs after every rule being triggered. So, 20 minutes is correct.

10MINS 9VMs Cool down is 10 mins -> so next scale operation will be after 10mins. Duration of 10 mins -> It will not apply here as it is just to handle spikes. For example, 10 minutes means that every time autoscale runs, it will query metrics for the past 10 minutes. This allows your metrics to stabilize and avoids reacting to transient spikes.

answer seems to be correct , all the VM cpu should be 75 % for 10 mins to scale out so let say from 10 to 10:10 cpu > 75% then it will scale out first time by 10:10 then wait 10 min cool down then by 10:20 it will check again for 10 min so it can be scale out second time so by 10:30 it will scale out again if the condition is met so from 10:10 to 10:30 =20 min , answer is correct

wrong question , scale up means increase in the cpu , sku they should say scale out !!!

10MINS 9VMs

The default number is 3vms. If the cpu > 75% in 10mins, the 3vms will be added to make 6vms. If again all the 6vms cpu > 75% in 10mins, another 3vms will be added making 9vms. The total time required to make 9vms now is 10mins + 10mins = 20mins. for the second box, since the scale-in time is set to cpu < 25%. There will be no scale-in taking place as far as the cpu usage is 30%. so the number vms still remain 9. The given answer is correct.

10 9 correct answer.

I think the first answer is 20 mins. 00:00 - > start reaching over 75% 00:10 - > Start scale out to 6 VMs and wait for 10 mins cool down time 00:20 -> Scale out to 9 VMs

Default VM's in the question which is missing and the value is 6. Now based on the rule defined things will be scaled up or scaled-down. But still didn't understand how the option B has 9vms when it was cooled down

https://github.com/MicrosoftDocs/azure-docs/issues/17169#issuecomment-431136702 The comments on here are good. It says if scale up/out cooldown is 10 minutes and scale down/in cooldown is 30. The scale up/out rule will take effect 10 minutes after the last action took place whether it be up/out or down/in scale rule(whichever the case may be). Therefore, the CORRECT answer to this question is 10 minutes and 9 instances.

answer should be 10 min

In my opinion Duration The amount of time monitored before the metric and threshold values are compared. Does not include cool down period. Cool down (minutes) The amount of time to wait before the rule is applied again so that the autoscale actions have time to take effect. Therefore after a scale up trigger, it will wait 10minutes (cool down period) and then another 10min (duration) before comparing the metric for the next trigger to take effect.

Should be 30 for A first 10 min 3 snd 10 (20)min 3+3 ->6 Third 10 (30)min 6+3->9

What is the original VMs count?

1. > 20 minutes (10 minutes duration + 10 minutes cool down) Duration - The amount of time monitored before the metric and threshold values are compared. Does not include cool down period. Cool down - The amount of time to wait before the rule is applied again so that the autoscale actions have time to take effect. https://docs.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-autoscale-portal 2. > 9 virtual machines Because the scale-in threshold as never been hit

1) 10 2) 9 Very good explanation for the cool down here https://github.com/MicrosoftDocs/azure-docs/issues/17169#issuecomment-431136702