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Arjuna's avatar
Arjuna
10 months ago
Solved

LogicMonitor "Application ELB" Datasource returns NoData instead of metric for ELB 5XX

We have noticed "HTTPCode_ELB_5XX_Count” Datapoint from "AWS_Application_ELB” Datasource configured to collect "Raw Data” from AWS ELB following the Metric path "AWS/ApplicationELB>LoadBalancer:##sys...
alerts
ApplicationELB
cloudwatch
datapoint
datasource
http5XX
NoData
  • Mike_Moniz's avatar
    Mike_Moniz
    10 months ago

    Yeah, for example AWS_ELB and others have complex datapoints that looks like this:

    if(un(HTTPCode_Backend_5XX_Raw),0,HTTPCode_Backend_5XX_Raw)

    Which will return 0 if HTTPCode_Backend_5XX_Raw is NoData. Perhaps you can update AWS_Application_ELB to work the same way. Or put in a LM feature request to implement it in future versions.

Sarah_Terry's avatar
Sarah_Terry
Icon for Product Manager rankProduct Manager
10 months ago

Yes - it is because CloudWatch doesn’t actually report 0s via the API. So that means No Data could mean: there is no data because the load balancer is unresponsive or otherwise not working, OR it could mean: the value is 0. One reason we don’t automatically change No Data to 0 is that it eliminates the ability to alert on that first No Data condition (the load balancer will always appear to be working from a monitoring perspective if we default No Data to 0). 

The best option is to use the complex datapoint option above, but instead of doing it based on the raw metric, use a different datapoint that should always return a value when the resource is functioning (like HealthyHostCount). We are trying to add these complex datapoints to more of our cloud out of the box modules.