Exam Professional Cloud Architect topic 1 question 190 discussion

C is correct answer: A. Change the Target type to DELTA_PER_MINUTE. (in this case the utlization tagret need to be in minutes which is not the case its percentage % and not time based. B. Change the Metric identifier to agent.googleapis.com/memory/bytes_used. (not applicable) C. Change the filter to metric.label.state = 'used' AND metric.label.state = 'buffered' AND metric.label.state = 'cached' AND metric.label.state = 'slab'. (this gives total memory used) D. Change the filter to metric.label.state = 'free' and the Target utilization to 20. (you would still need to change the the percent_used to percent_free) https://stackoverflow.com/questions/69267526/what-is-disk-data-cached-in-the-memory-usage-chart-metrics-of-gcp-compute-in https://cloud.google.com/compute/docs/autoscaler/scaling-cloud-monitoring-metrics

TARGET_TYPE: the value type for the metric. gauge: the autoscaler computes the average value of the data collected in the last couple of minutes and compares that to the utilization target. delta-per-minute: the autoscaler calculates the average rate of growth per minute and compares that to the utilization target. delta-per-second: the autoscaler calculates the average rate of growth per second and compares that to the utilization target. For accurate comparisons, if you set the utilization target in seconds, use delta-per-second as the target type. Likewise, use delta-per-minute for a utilization target in minutes.

Q: How come filter condition using "AND" for same column with different value? 'OR' is more appropriate here to add up all rows to check the metric sum exceed 80%, IMHO. If I'm missing something, please let me know. BTW I'm forced to choose an answer, hence I selected 'A'. But I feel the question itself is malformed...

This question is wrong and contradict with question 199, Q199 is the right one

There should always be a time reference when having a metric

exam done today, This question has been changed in the exam and the filter in the text of the question is actually "metric.label.state = 'used' AND metric.label.state = 'buffered' AND metric.label.state = 'cached' AND metric.label.state = 'slab'."

...but....propbably thwre is a mistake in the question. I assume that metric.label.state can't have many values in the same time so instead AND operator OR should be used ??????

To configure autoscaling based on the percent of used memory, specify the percent_used metric provided by the memory Ops Agent metrics. You should filter the metric by state to use only the used memory state. If you do not specify the filter, then the autoscaler takes the sum of memory usage by all memory states labeled as buffered, cached, free, slab, and used.

I'm preparing for a test and see that questions from 115 onwards are considered valid. Can anyone who's taken the test offer any insights or advice? Thank you!

C is the right option ( use used and gauge as options as in the guide listed here https://cloud.google.com/compute/docs/autoscaler/scaling-cloud-monitoring-metrics#autoscale_based_on_memory_usage

In the real exam "Filter: metric.label.state = 'used' AND metric.label.state = 'buffered' AND metric.label.state = 'cached' AND metric.label.state = 'slab'" is in the QUESTION. The answer should be: C. Change the filter to metric.label.state = 'used'

C is the correct approach. The current filter only considers memory in the "used" state. However, the operating system also uses memory for caching, buffering, and other purposes. By modifying the filter we ensure the autoscaling policy considers all memory states, providing a more accurate representation of total memory usage.

This question came in recent exam and default state already have all metric.label.state . Went with DELTE per minute option A

Question has a mistake "Filter: metric.label.state = 'used'" is in option C "Change the filter to metric.label.state = 'used' AND metric.label.state = 'buffered' AND metric.label.state = 'cached' AND metric.label.state = 'slab'." is actually in the queston. https://cloud.google.com/compute/docs/autoscaler/scaling-cloud-monitoring-metrics#autoscale_based_on_memory_usage You should use: Filter: metric.label.state = 'used'

The question in actual exam is reverse. The filter in the question is metric.label.state = 'used' AND metric.label.state = 'buffered' AND metric.label.state = 'cached' AND metric.label.state = 'slab'. and the option C is: Filter: metric.label.state = 'used' C is the correct answer in that case https://cloud.google.com/compute/docs/autoscaler/scaling-cloud-monitoring-metrics#autoscale_based_on_memory_usage

Actually this question is kinda weird We can discard A & B right away: A: If you change to DELTA_PER_MINUTE it'll calculate the difference in memory used from one minute to the other, and if that difference is bigger* than 80%, it'll trigger. Not what we want. B: If we change the metric to bytes_used, we must change the value of the gauge too. Not an option. Now comes the messy part. Following what is said in this page: https://cloud.google.com/monitoring/api/metrics_opsagent#agent-memory The metric.label.state should be ONE of these: [buffered, cached, free, slab, used] And it also states that: 'Summing the values of all states yields the total memory on the machine'. So, using a simple equation, if we remove the 'free' one from them, then that would give us the total memory that is being used. But remember, it said ONE of them, so that would discard it.

C is the correct one