What is Normalized RU Consumption

Question

We are using Cosmos DB as storage but confused of how to accurately calculate the consumed Request Unit. Our current setting is 375k RU/s.

First, I use request change in diagnostics to calculate. The result is that the max RU is 10k/s.

Second, I check the Metric Total Request Units. The curve shows the total RU per minute is about 300k, which means the average RU is 5k/s .

Third, I check the Metric Normalized RU Consumption.

It confused me that why we only use 10k RU/s, but Normalized RU consumption is 20% to 100%? What do request charge/Total Request Unit/Normalized RU consumption mean? How can we know the real consumption?

Answer 1

Normalized RU consumption is a value between 0% and 100% that tells you utilization of provisioned throughput.

For example:
Let's say that you have provisioned for 20K RU/s over two physical partitions - this setup means that each physical partition is limited to 10K RU/s.

At a certain point in time one of these partitions has a load of 2K RU/s (=20%) and the other 8K RU/s (=80%).

In this case you are actually using 2+8=10K RU/s which is 50% of your provisioned total, but the normalized consumption is 80% because at that point in time one of the partitions were at 80% of it's maximum.