Change the Calculation Method for an Existing Metric

You want to change how the Discards metric is calculated for the IfTableMIB vendor certification. Discards is an existing out-of-the-box metric.
capm250
You want to change how the Discards metric is calculated for the IfTableMIB vendor certification. Discards is an existing out-of-the-box metric.
  1. Make a GET REST call to export the full IfTableMIB vendor certification.
    http://
    da_hostname
    :8581/typecatalog/certifications/snmp/
    IfTableMIB
  2. Make a GET REST call to export existing extensions for the IfTableMIB vendor certification. 
  3. Find the metric expression that you want to change.
    <Expression destAttr="Discards"></Expression>
  4. Enter the new calculation in the vendor certification extension file.
    <Expression destAttr="Discards">(ifInDiscards+ifOutDiscards+ifInErrors+ifOutErrors)</Expression>
  5. Import the new extended vendor certification.
    http://
    da-hostname
    :8581/typecatalog/certifications/snmp/extension/
    IfTableMIB
    The DA resumes polling using the new extended IfTableMIB vendor certification. The new calculation for the Discards metric is applied.
  6. After 3 poll cycles (15 minutes), verify the new calculation in a CAPC view.
    1. Create a view using the new extended IfTableMIB vendor certification.
    2. Verify in 
      Performance Center
       that the new calculation for Discards is used.
Example
The following example shows how to define the new calculation in the vendor certification extension XML file:
<?xml version="1.0" encoding="UTF-8"?>
<DataModel xsi:noNamespaceSchemaLocation="SNMPCertificationFacet.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" namespace="http://im.ca.com/certifications/snmp">
<Author>CA</Author>
<Version>100.0</Version>
<FacetType descriptorClass="com.ca.im.core.datamodel.certs.CertificationFacetDescriptorImpl" name="IfTableMib">
<Documentation>Supports interfaces new metrics</Documentation>
<FacetOf namespace="http://im.ca.com/core" name="Item"/>
<Expressions>
<ExpressionGroup name="PortNRMDS" destCert="{http://im.ca.com/normalizer}NormalizedPortInfo">
<Expression destAttr="Discards">(ifInDiscards+ifOutDiscards+ifInErrors+ifOutErrors)</Expression>
</ExpressionGroup>
</Expressions>
</FacetType>
</DataModel>