No Error metric data from non-Cisco device interfaces in Performance Management

Products

• CA Infrastructure Management
• CA Performance Management
• Network Observability

Issue/Introduction

We received a report from one of our users that they are not receiving input error data from Nokia/Alcatel devices. This is concerning as we are potentially missing outages without this error data.

It affects all interfaces from all Nokia/Alcatel devices. All other devices examined, all Cisco devices, show data from the Error Metric without issue.

All devices are using the High Speed Interface Vendor Certification.

Environment

All supported Performance Management releases

Cause

Customized Errors Metric Expression seeks out a MIB OID that is Cisco specific. The OID isn't found on Nokia/Alcatel devices.

Without its value the metric expression isn't able to complete it's calculations.

This results in the metrics expression evaluating to a NULL for database insertion.

As a result all reports for these devices for the Errors metric would return "No Data Available" messages.

Resolution

Following the instructions in KB article ID 194970 we enabled the Detailed Poll Logging for the Interface Metric Family PollGroupID value.

Within we see the following messages and values returned from a sample interface for the MIB OIDs sought by this customized Errors metric expression.

First we see that the OID representing the etherStatsOversizedPkts attribute is not supported. That would make sense since it's a Cisco specific enterprise OID and these are Nokia/Alcatel devices.

Sep 08 19:09:20.260: itemID=630813, Last check for unsupportedOIDs=Tue Sep 08 18:24:20 UTC 2020
The following OIDs are not supported at last check
[1.3.6.1.4.1.9.9.276.1.1.1.1.5.1610891272]

The ifOutErrors OID returns a zero value. Not abnormal if things are working well.

Sep 08 19:09:20.344:    1.3.6.1.2.1.2.2.1.20.1610891272 = 0

The ifInErrors OID does return a non-zero value.

Sep 08 19:09:20.344:    1.3.6.1.2.1.2.2.1.14.1610891272 = 201

Due to the missing support for a key MIB OID required for the Errors metric expression, we insert a value of NULL into the DB after data processing takes place.

Sep 08 19:09:20.345:  DCMResponseVariable [name={http://im.ca.com/normalizer}NormalizedPortInfo.Errors, value=NULL ]

To resolve this you need to update change the RecalculatedIfInErrors to the line shown below. 

The variable is etherStatsOversizedPkts 1.3.6.1.4.1.9.9.276.1.1.1.1.5 and the line is the cert causing the issue is this: 

<Variable name="RecalculatedIfInErrors">ifInErrors-etherStatsOversizedPkts</Variable>

Change the line to this: 

<Variable name="RecalculatedIfInErrors">isdef(etherStatsOversizedPkts) ? ifInErrors-etherStatsOversizedPkts : ifInErrors</Variable>

This says to use the calculation (ifInErrors-etherStatsOversizedPkts) only if the variable has valid data else just use ifInErrors.