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Showing posts from June, 2017

Azure Portal CPU Graph Bug or Feature?

I support an Azure PaaS application.

We had a brief outage recently.

Given that the code had not been changed in a month, we suspected some maintenance in an Azure data center stepped on our application.

Ping tests and self-tests failed for approximately 10 minutes.

The outage resolved on its own without intervention.

I submitted a ticket to Azure Support to determine the cause of the outage but the reason I'm writing this post is because of the behavior I observed with the CPU graphs for Cloud Services while investigating the outage.

The CPU graphs show different results depending on the time range selected.

I would expect to see the CPU spike with the same value no matter what time range I selected. But, to see the spike that fired the alert, I had to to "Edit" the chart and select different time ranges to see the differences. It wasn't until I selected a narrow custom time range that the CPU graph would display the CPU spike that corresponded to the alert firing. The ale…