Smarts IP : How HighErrorRateActive event is computed for the Port_Performance_dot3_Ethernet

Products

• VMware Smart Assurance

Environment

VMware Smart Assurance - SMARTS

Resolution

Smarts will compute the port performance and determine the event "HighErrorRate "   This indicates that the percentage of error packets for either input or output exceeds the "ErrorThreshold."

= if MonitoringEnabled && NetworkAdapterOperational && ErrorThreshold < 100
check HighErrorRateActive || PolledMIBs_Error;
 
computed HighErrorRateActive_Computed
        = HighErrorRateActive_Computed_Dot3 ||
          HighErrorRateActive_Computed_MIB2;
 
HighErrorRateActive_Computed_Dot3 is computed as below
internal readonly computed attribute boolean HighErrorRateActive_Computed_Dot3
    = ((dot3StatsFrameTooLongsRate > MinimumErrorRate) &&
       (dot3StatsFrameTooLongsRate / InputPacketRate) * 100 > ErrorThreshold) ||

      ((dot3StatsFCSErrorsRate > MinimumErrorRate) &&
       (dot3StatsFCSErrorsRate / InputPacketRate) * 100 > ErrorThreshold) ||

      ((dot3StatsAlignmentErrorsRate > MinimumErrorRate) &&
       (dot3StatsAlignmentErrorsRate/InputPacketRate) * 100 > ErrorThreshold);

For example:
MinimumErrorRate                  = 2712.67
dot3StatsFrameTooLongsRate = 3625.27
InputPacketRate                       = 14543.6
ErrorThreshold                         = 10
 
Substituting the values in below formula:-
 
((dot3StatsFrameTooLongsRate > MinimumErrorRate) && (dot3StatsFrameTooLongsRate / InputPacketRate) * 100 > ErrorThreshold)
((3625.27 > 2712.67 ) && (3625.27/ 14543.6 )  * 100  > 10)
(TRUE) && (24.9269 > 10)
(TRUE && TRUE)
TRUE
Since the conditional statements are OR, the highlighted equations return TRUE. Hence the alert for HighErrorRate is a valid entry in this scenario.

Additional Information

If you suspect an issue with how this is calculated, 

With root permissions you can run the following sm_adapter command to subscribe to the output for a specific port instance.  

In order to troubleshoot issues we need to subscribeProp of the Performance attributes instrumentation of  port for some polling cycles
./sm_adapter -s <domain name> --subscribeProp=NetworkAdapter_PerformanceData_ifMIB::  I-NetworkAdapter_PerformanceData_ifMIB-<Port instance> ::.*/v --subscribeProp=Port_Performance_dot3_Ethernet:: I-Port_Performance_dot3_Ethernet-<Port instance> ::.*/v --output=Subscription

For example :-
./sm_adapter -s INCHARGE-AM-PM --subscribeProp=NetworkAdapter_PerformanceData_ifMIB::  I-NetworkAdapter_PerformanceData_ifMIB-PORT-inch-vss-cs01/170 ::.*/v --subscribeProp=Port_Performance_dot3_Ethernet:: I-Port_Performance_dot3_Ethernet-PORT-inch-vss-cs01/170 ::.*/v  --output=Subscription

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