Splunk Search

eval - inconsistent math result

splunk_zen
Builder

How is it possible that an eval expression which its components total weight is 100, breach that expected value?

For a given period, I'm getting a result of 101,

while expression components weights are (it totals to 100)

100*(0.08 + 0.03 + 0.12 + 0.16 + 0.06 + 0.18 + 0.06 + 0.06 + 0.25)

and there is not even one component value which exceeds 1.

| eval TimeoutScore=100*( 
0.08*(bw1sdpSdfPccCsApdex) 
+ 0.03*bw1sdpSdfPccMnCsApdex 
+ 0.12*bw1sdpSdfPccPsApdex 
+ 0.16*(0.5*bw1sdpSdfPpsCsApdex +0.5*bw2sdpSdfPpsCsApdex) 
+ 0.06*(0.5*bw1sdpSdfPpsMnCsApdex +0.5*bw2sdpSdfPpsMnCsApdex)
+ 0.18*(0.5*bw1sdpSdfPpsPsApdex + 0.5*bw2sdpSdfPpsPsApdex)
+ 0.06*(0.5*bw1sdpSdfPpsVisaCsApdex + 0.5*bw2sdpSdfPpsVisaCsApdex) 
+ 0.06*bw1careSdfMnApdex 
+ 0.25*(0.5*bw1sdpSdfSlrApdex + 0.5*bw2sdpSdfSlrApdex))
| stats sum(TimeoutScore) as TimeoutScore sum(bw1sdpSdfPccCsApdex) sum(bw1sdpSdfPccMnCsApdex)     sum(bw1sdpSdfPccPsApdex) sum(bw1sdpSdfPpsCsApdex) sum(bw2sdpSdfPpsCsApdex) sum(bw1sdpSdfPpsMnCsApdex) sum(bw2sdpSdfPpsMnCsApdex) sum(bw1sdpSdfPpsPsApdex) sum(bw2sdpSdfPpsPsApdex) sum(bw1sdpSdfPpsVisaCsApdex) sum(bw2sdpSdfPpsVisaCsApdex) sum(bw1careSdfMnApdex) sum(bw1sdpSdfSlrApdex) sum(bw2sdpSdfSlrApdex)


TimeoutScore    sum(bw1sdpSdfPccCsApdex)    sum(bw1sdpSdfPccMnCsApdex)  sum(bw1sdpSdfPccPsApdex)    sum(bw1sdpSdfPpsCsApdex)    sum(bw2sdpSdfPpsCsApdex)    sum(bw1sdpSdfPpsMnCsApdex)  sum(bw2sdpSdfPpsMnCsApdex)  sum(bw1sdpSdfPpsPsApdex)    sum(bw2sdpSdfPpsPsApdex)    sum(bw1sdpSdfPpsVisaCsApdex)    sum(bw2sdpSdfPpsVisaCsApdex)    sum(bw1careSdfMnApdex)  sum(bw1sdpSdfSlrApdex)  sum(bw2sdpSdfSlrApdex)
101 1   0.854839    0.972727    1   1   1   1   0.975410    1   1   1   0.983871    1   1

EDIT:
Thanks to kristian.kolb suggestion, this issue was solved replacing

| eval TimeoutScore=...

by

| eval TimeoutScore=exact(...)
Tags (2)
0 Karma
1 Solution

kristian_kolb
Ultra Champion

splunk_zen
Builder

Dammit... Forgot that could be the culprit.
If you promote the comment to an answer I will gladly accept it 🙂

0 Karma

kristian_kolb
Ultra Champion

Rounding errors? perhaps the exact() function for eval might help?

http://docs.splunk.com/Documentation/Splunk/latest/SearchReference/CommonEvalFunctions

Got questions? Get answers!

Join the Splunk Community Slack to learn, troubleshoot, and make connections with fellow Splunk practitioners in real time!

Meet up IRL or virtually!

Join Splunk User Groups to connect and learn in-person by region or remotely by topic or industry.

Get Updates on the Splunk Community!

A Four-Part Event Series: Full Stack Observability For the AI Era

As AI reshapes applications, infrastructure, and the way teams operate, the traditional boundaries of ...

SOC4Kafka - New Kafka Connector Powered by OpenTelemetry

The new SOC4Kafka connector, built on OpenTelemetry, enables the collection of Kafka messages and forwards ...

Event Series: Level up your SOC: Advancing with Splunk Enterprise Security

AI has fundamentally raised the stakes for security operations, and this three-part series is your guide to ...