ResponseTime_Detail not matching Nodes

joseph.peters

I'm seeing an issue where the values which are appearing in the 'Nodes' table are not matching what is stored in the 'ResponseTime_Detail' table.

Looking at a single node in the 'Nodes' table for the last 30 minutes I've been seeing the 'PercentLoss' field fluctuate in value between 10 and 30 but never be zero.  I kept running the query below after each 'NextPoll' time and recording the value:

SELECT nodeid

  ,caption

  ,ResponseTime

  ,AvgResponseTime

  ,MinResponseTime

  ,PercentLoss

  ,LastSync

  ,NextPoll

  FROM [NetPerfMon].[dbo].[Nodes]

  where nodeid = 1234

When I compare this to the ResponseTime_Detail table for the same node over the same time range using the query below:

SELECT TOP 1000 [NodeID]

      ,[DateTime]

      ,[AvgResponseTime]

      ,[MinResponseTime]

      ,[MaxResponseTime]

      ,[PercentLoss]

      ,[Availability]

      ,[Archive]

  FROM [NetPerfMon].[dbo].[ResponseTime_Detail]

  where nodeid = 1234

  and datetime between '2015-11-17 11:00' and '2015-11-17 11:30'

I see the PercentLoss value as 0 over the entire range except for a couple of entries which show 100. 

It is almost as if I'm looking at two different nodes.  Has anyone else seen this before or know why it might be happening?

joseph.peters

To document this better I began accumulating snapshots of the Nodes table into a database.  Below is a comparison of what the Nodes table was showing at each timestamp compared to a query against the ResponseTime_Detail table for the same time range.  As you can see there is a period where the Nodes table was reporting packet loss but those same entries are showing 0 packet loss in the ResponseTime_Detail.