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Mattias260's avatar
Mattias260
Copper Contributor
Feb 22, 2021

Loganalytics - Query not able to create a chart?

Hi, I am pretty new with Azure LogAnalytics.

 

I am running this Query and I get expected result.

 

// Not reporting VMs
// VMs that have not reported a heartbeat in the last 5 minutes.
// To create an alert for this query, click '+ New alert rule'
Heartbeat
| where TimeGenerated > ago(24h)
| summarize LastCall = max(TimeGenerated) by Computer
| where LastCall < ago(5m)

 

But when I select "Chart" I get the following error message:

 

Failed to create visualization The Stacked Column can't be created as you are missing a column of one of the following types: int, long, decimal or real

 

Do you know how to get this chart working, how to I fix this?

 

Many Thanks,

Mattias

 
 

3 Replies

  • loadedlouie270's avatar
    loadedlouie270
    Copper Contributor
    Mar 25, 2021

    Hi Mattias260, sorry for not helping you resolve the matter, but today i encounter the same problem running this query : 

     

    So i got results, however, when I switch to chart view, I got the same error as you: 

     

    Does anyone know what's going on? 

    I'm assuming that this is something related to the type of the fields/columns in log analytics, or the chart not looking to the correct values. 

     

     

     



    • loadedlouie270's avatar
      loadedlouie270
      Copper Contributor
      Mar 25, 2021
      Digging a bit further i look into the query and exported into powerbi.

      When i have done this the fields are has "text" fields....

      So im guessing this is the problem with log analytics, its looking into it, but it sees the field as a "text" colunm instead of the "decimal Number" type of row...

      I'm assuming that is is somehow related to a issue that log analytics reported a few weeks about a "missing" colunm...

      I hope someone at microsoft, look at it and fix it.
      • loadedlouie270's avatar
        loadedlouie270
        Copper Contributor
        Mar 26, 2021

        And here is a quick fix,

        Add the following line for each of your decimal values,

        |extend cpu = todecimal(avg_cpu_percent_s)

         

        Explaining what it does: 
        (extend command, follow by the name of the new colunm, in this case "cpu", provide a equal "=", and the command, "todecimal(nameofthecolumn).
        this will create a new column and convert the avg_cpu_percent_s, to a decimal value, allowing the chart in log analytics to process it since it sees it in the new column as a number.

        Hope it helps, and microsoft solve this, i manage a few subscriptions, and i got the same error in all of them, so its a wide spread bug to my opinion, and there will be more people complaining over time.

        Hope this helps.

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