Getting Data In

how to configure log4net with nested JSON?

ttovarzoll
Path Finder

This is really a log4net question but I'm hoping the folks here can help; I have been unsuccessful at searching online for a solution.

-----------------

We have a custom application which generates local logs in JSON format via the log4net module. We then have a Splunk UF installed to collect said logs. In general that all works fine. The problem is that some log messages include a nested JSON 'message' field -- but log4net is misformatting it as a string and so Splunk doesn't parse the nested part.

You can see the issue (below) where log4net is unnecessarily adding quote-marks around the nested part:

CURRENT/INVALID

 

"message":"{"command":"Transform271ToBenefitResponse","ms":1}"

 

PROPER

 

"message":{"command":"Transform271ToBenefitResponse","ms":1}

 

--------------------------

I'm not entirely sure of the log4net configuration but here's what I was told by one of our developers:

ORIGINAL LOG4NET CONFIG

<conversionPattern value="%utcdate [%property{CorrelationId}] [%property{companyId}] [%property{userId}] [%thread] [%level] %logger - %message%newline" />

UPDATED CONFIG; STILL FAILS

<conversionPattern value="{&quot;date&quot;:&quot;%date{ISO8601}&quot;, &quot;correlationId&quot;:&quot;%property{CorrelationId}&quot;, &quot;companyId&quot;:&quot;%property{companyId}&quot;, &quot;userId&quot;:&quot;%property{userId}&quot;, &quot;thread&quot;:&quot;%thread&quot;, &quot;level&quot;:&quot;%level&quot;, &quot;logger&quot;:&quot;%logger&quot;, &quot;message&quot;:&quot;%message&quot;}%newline" />

 

 

 

 

 

 

 

 

Labels (1)
Tags (1)
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!

Data Management Digest – September 2026

    Welcome to the September 2026 edition of Data Management Digest! September brought a fresh wave of ...

Federated Search for CloudWatch Unified Data Store Is Generally Available

As organizations modernize their cloud environments, AWS workloads generate more security, operational, and ...

Announcing Modern Navigation: A New Era of Splunk User Experience

We are excited to introduce the Modern Navigation feature in the Splunk Platform, available to both cloud and ...