a3y3
a3y3

Reputation: 1211

GCE shows only ~15% usage but top shows ~99%

I was running a load test but seeing only ~20% CPU on GCE. That was surprising, so I decided to SSH into my machine and run top, which showed me 99.7% utilization.

I found a question that was very similar: Google Cloud Compute engine CPU usage shows 100% but dashboard only shows 10% usage

However, I am certain I only have one core (1 vCPU, 3.75 GB memory).

Here's top running that shows 99.7% utilization:

top

What could be the reason for this?

Upvotes: 0

Views: 127

Answers (1)

mebius99
mebius99

Reputation: 2605

Even for a single core case, when workload is not split between several cores, the curve shape and the Y-coordinate of the CPU Utilization chart depend on the aggregation and alignment settings you use: for instance max or mean, 1m or 1h alignment period, etc. For instance in case of a short peak load, the wide time window will act as a big denominator for the mean aligner. That way you'll get lower values on the chart.

For more details please see:

Google Monitoring > Documentation > Alignment

Google Cloud Blog > Stackdriver tips and tricks: Understanding metrics and building charts

Upvotes: 1

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