Sub-task 2: Strange handling of Consume Cores 
 

A user reports the following:

Thanks for helping with my previous question. I have gotten a bit further now and have managed to write a flow that we use for testing how the service behaves under very heavy CPU load. On the four core machine we have I am consuming two, three and all four cores in my flow, and checking the performance in between.

It mostly seems good, but in the last stage when I consume all four cores I am getting suspiciously good results. I would expect the performance to be around 3%, but I am getting way beyond that.

I have tested running the Tweaker manually, and I see a clear difference in performance when consuming 3 vs 4 cores. Can you help me figure out what is wrong?

Here is the flow that I am running.

 

{

    "hostname": "host.name",

    "tasks": [

        {

            "type": "TweakerTask",

            "description": "Consume two cores",

            "mode": "ConsumeCores",

            "tweak": 2

        },

        {

            "type": "CollectorTask",

            "description": "Measure performance",

            "mode": "Performance",

            "threshold": 30,

            "millisecondDuration": 1000

        },

        {

            "type": "TweakerTask",

            "description": "Consume three cores",

            "mode": "ConsumeCores",

            "tweak": 3

        },

        {

            "type": "CollectorTask",

            "description": "Measure performance",

            "mode": "Performance",

            "threshold": 10,

            "millisecondDuration": 1000

        },

        {

            "type": "TweakerTask",

            "description": "Consume four cores",

            "mode": "ConsumeCores",

            "tweak": 4

        },

        {

            "type": "CollectorTask",

            "description": "Measure performance",

            "mode": "Performance",

            "threshold": 10,

            "millisecondDuration": 1000

        }

    ]

}