 SOLVED

# Getting the rank of a CounterValue

Occasional Contributor

# Getting the rank of a CounterValue

I'm having issues designing a query in Log Analytics. My goal is to get the computer's CPU rank out of 100 by comparing it to other LogAnalytics computers.

``````let CPUavgOfMyComputer = Perf
| where Computer contains "myComputerName"
| where ObjectName == 'Processor' and CounterName == '% Processor Time' and InstanceName == '_Total'
| summarize avg(CounterValue);
Perf
| where ObjectName == 'Processor' and CounterName == '% Processor Time' and InstanceName == '_Total'
| summarize tdigestRes = tdigest(CounterValue), count()
| project rank_tdigest(tdigestRes, CPUavgOfMyComputer) * 100.0 / count_``````

I'm pretty sure my issue comes from my syntax on the rank_tdigest function (TDigest, Expr).

Can we use a variable for Expr ?

2 Replies
best response confirmed by SebasL (Occasional Contributor)
Solution

# Re: Getting the rank of a CounterValue

It was asking for a scalar expression, like this:

``````let CPUavgOfMyComputer = toscalar(Perf
| where Computer has "name here"
| where ObjectName == 'Processor' and CounterName == '% Processor Time' and InstanceName == '_Total'
| summarize avg(CounterValue));
Perf
| where ObjectName == 'Processor' and CounterName == '% Processor Time' and InstanceName == '_Total'
| summarize tdigestRes = tdigest(CounterValue), count()
| project rank_tdigest(tdigestRes, CPUavgOfMyComputer) * 100.0 / count_``````

# Re: Getting the rank of a CounterValue

Thanks! that work 