Details
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Type:
Bug
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Status: Resolved (View Workflow)
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Priority:
Critical
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Resolution: Fixed
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Affects Version/s: 18.0.0
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Fix Version/s: 18.0.3, Meridian-2016.1.4, 19.0.0
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Component/s: REST
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Security Level: Default (Default Security Scheme)
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Labels:
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Sprint:Horizon - Nov 2nd, Horizon - Nov 9th
Description
IMPORTANT: THE FOLLOWING WON'T HAPPEN WHEN USING RRDTOOL.
The following was verified with latest foundation-2016 and latest snapshot for Meridian-2016.1.0:
1) When using MIN or MAX as the aggregation function when calling the following ReST end-point, weird values are returned:
/opennms/rest/measurements/{resourceId}/{metricId}
Here are examples:
<query-response end="1465829299271" start="1465829099271" step="30000"> <columns> <values>4.9E-324</values> <values>4.9E-324</values> <values>4.9E-324</values> <values>4.9E-324</values> <values>4.9E-324</values> <values>4.9E-324</values> <values>4.9E-324</values> <values>4.9E-324</values> <values>4.9E-324</values> </columns> <labels>avgBusy5</labels> <timestamps>1465829070000</timestamps> <timestamps>1465829100000</timestamps> <timestamps>1465829130000</timestamps> <timestamps>1465829160000</timestamps> <timestamps>1465829190000</timestamps> <timestamps>1465829220000</timestamps> <timestamps>1465829250000</timestamps> <timestamps>1465829280000</timestamps> <timestamps>1465829310000</timestamps> </query-response>
<query-response end="1465831042024" start="1465830942024" step="30000"> <columns> <values>1.7976931348623157E308</values> <values>1.7976931348623157E308</values> <values>1.7976931348623157E308</values> <values>1.7976931348623157E308</values> <values>1.7976931348623157E308</values> </columns> <labels>avgBusy5</labels> <timestamps>1465830930000</timestamps> <timestamps>1465830960000</timestamps> <timestamps>1465830990000</timestamps> <timestamps>1465831020000</timestamps> <timestamps>1465831050000</timestamps> </query-response>
2) According with the documentation, step=1 means:
Requested time interval between rows. Actual step may differ. Set to 1 for maximum accuracy.
When using Newts, it uses whatever value is configured for org.opennms.newts.query.minimum_step in opennms.properties instead the configured step on collectd-configuration.xml. This is kind of confusing as this is not the case when using RRDtool.
For now, you have to provide a more precise step, which is problematic if you have different collection step for different devices on collectd-configuration.xml, specially when the final user of this ReST end point doesn't know the collection interval for a given device.
