Splunk Search

Multiple capture groups not capturing

arielbintang
New Member

I have the following log structure:

  2023-11-25T21:18:54.244444  [  info      ]  I am a log message  request = GET /api/myendpoint    request_id = ff223452

I can capture the date and time (without the 244444 part) using:

rex field=myfield "(?<timestamp>\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2})\.\d+"

and timestamp is properly captured.

But if I try to extend this and want to capture the log level as well with for example:

rex field=myfield "(?<timestamp>\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2})\.\d+\s+\[\s*(?<loglevel>\w+)\s*\]\s+"

It didn't work; none of the timestamp nor the loglevel is captured.

What am I doing wrong?

Labels (2)
0 Karma

ITWhisperer
SplunkTrust
SplunkTrust

You don't appear to be doing anything wrong, given the example you have shared.

| makeresults
| eval _raw="2023-11-25T21:18:54.244444  [  info      ]  I am a log message  request = GET /api/myendpoint    request_id = ff223452"
| rex "(?<timestamp>\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2})\.\d+\s+\[\s*(?<loglevel>\w+)\s*\]\s+"
0 Karma

arielbintang
New Member

Thanks for verifying! When I copy paste my log directly to the search box from the log message field and used your makeresults, I see that actually some of the spaces are actually  character; do you know why perhaps its not shown in the results itself (and I have to copy paste)?

0 Karma

ITWhisperer
SplunkTrust
SplunkTrust

Assuming that the non-word characters are in the square brackets, you could try something like this

| makeresults
| eval _raw="2023-11-25T21:18:54.244444  [  info      ]  I am a log message  request = GET /api/myendpoint    request_id = ff223452"
| rex "(?<timestamp>\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2})\.\d+\s+\[\W*(?<loglevel>\w+)\W*\]\s+"

but, ideally, you should ask the developers of the application to not use these characters in the first place.

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!

From Data to Insight: Announcing the Winners of the Splunk Dashboard Contest

Hi Splunkers, First off, thank you to everyone who participated in our very first From Data to Insight: The ...

Splunk Developers: Construct Your Future at the .conf26 Builder Bar

Calling all Splunk architects, platform admins, and app developers: the site is open, and the blueprints are ...

Quick connection discovery mode for forwarders

When a Splunk forwarder loses connectivity to its indexers, it does not always reconnect immediately. In many ...