Forum Discussion
Calculating rate of change in Log Analytics
If I have a counter that increases over time and I want to display how much that counter is changing every minute, how would I do that. In PromQL I would use the rate function but is there a simple equivalent KQL?
For example, 14:10:00 the total value since we collected data was 182077, at 14:11 it was 182083 and at 14:12 it was 182084. I would like to render a graph showing 0 at 14:10, 6 at 14:11 and 1 at 14:12.
Sounds simple but I can't see a way to do it. Any help would be appreciated.
Regards
Pete
CliveWatson you are a scholar and a gent. That would appear to do the trick. I'll adapt as necessary but thank you
8 Replies
Have you looked at bin? https://docs.microsoft.com/en-us/azure/kusto/query/binfunction
Event | where TimeGenerated > ago(1h) | summarize count(EventID) by bin(TimeGenerated, 1m)This shows the count of EventIDs in the Events table every min in the past hour?
Go to Log Analytics and Run Query
Adding as this as the last line will give you the graph, rather than a table.
| render barchartCliveWatson Thanks for the reply. I have looked at that. It's not the number of new entries per minute I am trying to ascertain, but the change in the sum of all previous entries per minute, if that makes sense.
ie in the above query, you'll see system mode cpu usage for computer aks-agentpool-31816283-2 goes from 264552.21 to 264560.83 in the minute, so i want the difference between those 2 on an on-going basis. In fact, I actually want it for all modes but one step at a time.
Peter Hall Did you find out prometheus "rate" equivalent function in kusto
