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Title
How does Optimizer calculate CPU usage peak -
Description
When looking at Optimizer in Foglight for Virtualization Enterprise Edition, how are CPU peak calculated under the column "Peak Utilization". This is relevant when choosing the configuration setting "Maximum Peak Utilization". -
Cause
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Resolution
A key point to remember is that Optimizer is designed to work with sustained peak of CPU MHz used and not by any one spike. In Optimizer, a peak is by default a period of 15 minutes where the usage is above the average by 5 percent.
Variables used and defaults
optimizer.peak-threshold
threshold in %, the default value is 5.
Variable type is LONG. Valid values are [1-50]
All points above the (avg(day points) * (100 + peak-threshold) / 100) level used for peaks calculations
optimizer.peak-min-length
duration in milliseconds, default value is 900000.
Variable type is LONG. Valid values are [300000-86400000]
This is minimal continuous length of points above the peak level, which could be saved as a single peak.
How to change these variables (by default they do not exist in the FMS variable registry manager):
To change the peak calculation period:
1. Navigate to Dashboards | Administration | Rules & Notifications | Manage Registry Variables
2. Click Add…
3. Select Long as the Variable type
4. Click Next
5. Enter optimizer.peak-min-length in the variable Name field
6. Select Static Value
7. Enter a new peak calculation period in milliseconds without any commas in the Enter desired value box (For example 1200000)
8. Click Finish
To change the peak threshold percentage:
1. Navigate to Dashboards | Administration | Rules & Notifications | Manage Registry Variables
2. Click Add…
3. Select Long as the Variable type
4. Click Next
5. Enter optimizer.peak-threshold in the variable Name field
6. Select Static Value
7. Enter a new peak percentage without the percent sign in the Enter desired value box (For example 6)
8. Click Finish
New registry variable values will be used on the all next peaks calculations.