How does CA Performance Management (CAPM) calculate the Average Memory Utilization

Products

• CA Infrastructure Management
• CA Performance Management - Usage and Administration
• DX NetOps

Issue/Introduction

How can the the Average Memory Utilization values in CAPM be validated?

Environment

All PM releases

Resolution

Average Memory Utilization is calculated as follows.  Using as an example, the vendor certification ‘Cisco CPM Memory’:
 
Formula for Utilization:

snmpProtectedDiv ((100.0 * cpmCPUMemoryUsed),(cpmCPUMemoryFree + cpmCPUMemoryUsed))

Find the OID’s on Google:

cpmCPUMemoryUsed = 1.3.6.1.4.1.9.9.109.1.1.1.1.12.$1
cpmCPUMemoryFree = 1.3.6.1.4.1.9.9.109.1.1.1.1.13.$1

OID’s values from Spectrum MIB tools:

cpmCPUMemoryUsed  7  3886600     Gauge 1.3.6.1.4.1.9.9.109.1.1.1.1.12
cpmCPUMemoryFree  7  64080       Gauge 1.3.6.1.4.1.9.9.109.1.1.1.1.13

Calculating:

Memory Utilization = cpmCPUMemoryUsed / cpmCPUMemoryUsed + cpmCPUMemoryFree

= (3886600) / (3886600 + 64080) 
= 3886600 / 3950680 
= 0.9837800074923811 * 100
= 98.37%

From the above, it can be confirmed that the Average Memory Utilization calculation is correct by checking with the Device Administrator if it reports the same value. If the value on the device is different, then it's possible that the wrong OIDs are being used due to the wrong Vendor Certification (VC) being set for the device. You can change the VC to a more appropriate one as per:

KB : Cisco Memory processor pool Utilization is reporting higher in CAPM than the device

Note: If the OID has an index, you aggregate the values for each index instance as per:

cpmCPUMemoryUsed:

1.3.6.1.4.1.9.9.109.1.1.1.1.12.19, Gauge , 2819964
1.3.6.1.4.1.9.9.109.1.1.1.1.12.20, Gauge , 3107712

cpmCPUMemoryFree:

1.3.6.1.4.1.9.9.109.1.1.1.1.13.19, Gauge , 1157900
1.3.6.1.4.1.9.9.109.1.1.1.1.13.20, Gauge , 870152
 
Memory Utilization = cpmCPUMemoryUsed / cpmCPUMemoryUsed + cpmCPUMemoryFree
= (2819964 + 3107712) / ((2819964 + 3107712) + (1157900 + 870152))
= 5927676 / (5927676 + 2028052)
= 5927676 / 7955728
= 0.74508278815 * 100
= 74.51%