Knowledge Management

Reference a calculated field within another calculated field

RWL01
Engager

Is it possible to reference a calculated field within another calculated field?

My original search query was:

| eval SourceServer=substr(source, 11, 6)
| eval SourceInstance=case(
     SourceServer=="AAA001", "PROD", 
     SourceServer=="AAA002", "PROD", 
     SourceServer=="BBB001", "UAT", 
     SourceServer=="BBB002", "UAT",
    1=1, "UNKNOWN")

My intention was to create two calculated fields. However, it doesn't look like SourceServer is processed before SourceInstance is, so all of the Events resolve to "UNKNOWN".

My alternative is to repeat the same logic for each option in the case statement which seems pretty inefficient.

SourceInstance

case(
     substr(source, 11, 6)=="AAA001", "PROD", 
     substr(source, 11, 6)=="AAA002", "PROD", 
     substr(source, 11, 6)=="BBB001", "UAT", 
     substr(source, 11, 6)=="BBB002", "UAT",
    1=1, "UNKNOWN")

When I try to chain them together in a single field, like the simplified example below I get the error "Encountered the following error while trying to update: Unexpected token"

| eval foo=4 | eval bar=foo+4

Is there anyway to accomplish the logic of my original query without having to repeat the first query for every option of the case statement in the second query?

Tags (1)
0 Karma

MuS
SplunkTrust
SplunkTrust

Hi RWL01,

there must be something wrong somewhere else, because both examples work fine here:

First one:

| makeresults 
| eval SourceServer=substr("ZZZZZZZZZZAAA001", 11, 6) 
| eval SourceInstance=case(
    SourceServer=="AAA001", "PROD", 
    SourceServer=="AAA002", "PROD", 
    SourceServer=="BBB001", "UAT", 
    SourceServer=="BBB002", "UAT",
    1=1, "UNKNOWN")

alt text

As well as the second one:

alt text

cheers, MuS

0 Karma
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!

Laser Bananas and Edge Hubs: Exploring Operational Technology (OT) Data Through a ...

  OT is a different environment to traditional IT and can have interesting challenges when interfacing the ...

Event Series: Mastering AI Tokenomics and Splunk Agent Observability

Beyond the Black Box: Correlating AI Performance and Tokenomics with Splunk Agent Observability   As ...

span_metrics: The OpenTelemetry-Idiomatic Way to See Inside Your Services

You open a trace in Splunk Observability Cloud and everything looks fine. One root span, order-pipeline, with ...