Forum Discussion
Mali_Stane
Mar 28, 2024Copper Contributor
Azure Metric vs Performance counters show different values
Azure Metric vs Performance counters
Return values of network traffic are totally off, regardless of time frame between portal, log analytic query perf and InsightsMetrics. See screen off excel.
I have open log analytic workspace, select Time range Last 24 hours and one day 26/03/2024
Perf
| where TimeGenerated between (datetime(2024-03-26) .. datetime(2024-03-27))
| where Computer == "**********"
| where ObjectName == "Network Interface" and CounterName == "Bytes Sent/sec" or CounterName == "Bytes Received/sec"
| summarize BytsSent = sum(CounterValue) by bin(TimeGenerated, 1d),CounterName
InsightsMetrics
| where TimeGenerated between (datetime(2024-03-26) .. datetime(2024-03-27))
| where Origin == "vm.azm.ms"
| where Computer == "*******"
| where Namespace == "Network"
| where Name == "ReadBytesPerSecond" or Name == "WriteBytesPerSecond"
| extend Tags = parse_json(Tags)
| extend BytestoSec = toreal(Tags.["vm.azm.ms/bytes"])
| sort by TimeGenerated
| project TimeGenerated,Name,Val,BytestoSec
| summarize AggregatedValue = sum(BytestoSec) by bin(TimeGenerated, 1d),Name
I don’t know what im doing wrong or i don't understand . But sample interval in data collection rule is 15s, and sample interval of metric is 60s.
- AdeelazizBrass ContributorI've run into something similar in the past. My understanding is that performance counters return data from the OS perspective whereas metrics are how Azure sees usage from a host perspective. I would rely on the performance counter data in Log Analytics over metric data.
- BlatniBPMCPCopper ContributorCorrectly.
According to the tests and metrics collected on the network infrastucture is log analytic value is more exact/ identical to what ststistic is provide. Azure metric is more or less general information, how system behave that is in my opinion.