Splunk Search

How to extract missing event date from header

trs01
New Member

Hello, I'm trying to index a log in the IIS W3C Extended Log Format. The date information in each event is missing, but the date is at the top of the file in the header info. The time (HH:MM:SS) is correctly populated in each event. Is there a way I can extract the date from the header and prepend it to each line or a way I can populate the date_mday, date_month, date_year, etc. fields for each event using the info in the header? Sample data below.

Current sourcetype definition

[ iis:log ]
CHARSET=UTF-8
FIELD_DELIMITER=whitespace
FIELD_HEADER_REGEX=^#Fields:\s*(.*)
INDEXED_EXTRACTIONS=W3C
LINE_BREAKER=([\r\n]+)
MISSING_VALUE_REGEX=-
NO_BINARY_CHECK=true
SHOULD_LINEMERGE=false
TIME_FORMAT=%H:%M:%S
TIMESTAMP_FIELDS=Date,time

Sample log file

#Version:   1.0
#Fields:    Date time cs(X-Forwarded-For) cs(Cookie)
#Software:  WebLogic
#Start-Date:    2019-09-03  00:00:00
-   00:00:00    col_3_data  col_4_data
-   00:00:00    col_3_data  col_4_data
-   00:00:06    col_3_data  col_4_data
-   00:00:06    col_3_data  col_4_data
-   00:00:08    col_3_data  col_4_data
-   00:00:08    col_3_data  col_4_data
-   00:00:08    col_3_data  col_4_data
-   00:00:08    col_3_data  col_4_data
-   00:00:09    col_3_data  col_4_data
-   00:00:09    col_3_data  col_4_data
-   00:00:09    col_3_data  col_4_data
-   00:00:09    col_3_data  col_4_data
-   00:00:09    col_3_data  col_4_data
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!

SOC4Kafka - New Kafka Connector Powered by OpenTelemetry

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

Rounding off the Splunk Dashboard Contest

What does a contest-winning Splunk dashboard look like? In this case, it isn't in a browser tab at all. It ...

A Four Part Event Series: AI + Observability: AI Agents, LLMs, Apps, & Infrastructure

AI + Observability: AI Agents, LLMs, Apps, & Infrastructure The rapid evolution of artificial intelligence ...