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How CPU and Memory Utilization (Thresholds ) are calculated on the Performance Tab in Spectrum Oneclick.


Article ID: 45979


Updated On:


CA Spectrum DX NetOps


How CPU and Memory Utilization (Thresholds ) are calculated on the Performance Tab in Spectrum Oneclick.


Release: All Supported Releases

Component: SPCCSS - SpectroSERVER Core


Typically vendors may supply various  values for CPU and memory usage and Spectrum will use one of them to plot the graph on the performance tab. These values are stored in NRM_CPUUtilAttr 0x12e2d or NRM_MemoryUtilAttr 0x12e36. These attributes can be redirected as needed, per what the vendor provides. 

For example,  Juniper provides the following information how to monitor CPU utilization (in percentage) on the firewall via SNMP.

To monitor CPU utilization (in percentage), the following OIDs can be used: 

. Average System CPU utilization in percentage. 

. Last one minute CPU utilization in percentage. 

. Last Five minute CPU utilization in percentage. 

. Last Fifteen minute CPU utilization in percentage.


In the this situation, Spectrum has 4 different values to choose from, as can be seen from the attributes tab below.  We can filter by CPU or use the above OIDs if the OID prefix column is visible.   The vendor attributes begin with NsResCPU and the internal CA normalised attributes begin with NRM_CPU.

The NRM_CPUIntelPref shows a value of redirection. 

NRM_CPUUtilAttr showed a value of 0x49b0147 corresponding to NsResCpuLast5Min so the value displayed by Spectrum is the average value over 5 minutes.


To change the value displayed by Spectrum, we can double click on NRM_CPUUtilAttr and it to point to another attribute value.

Example, changing the value of  NRM_CPUUtilAttr to 0x49b0146 will display the CPU usage over the last minute.

NOTE: Not every vendor device meets the requirements for CPU and Memory utilization calculations. The device must first meet these requirements in order for Spectrum to be allowed to poll and display proper CPU and Memory metrics. 

Additional Information

Please reference the "Normalized CPU Utilization Attributes" and "How CA Spectrum Calculates CPU and Memory" sections of the documentation for more information.

Link for  "Normalized CPU calculation requirements"