# Grok... is it just me or is it really that difficult?

**URL:** <https://discuss.elastic.co/t/grok-is-it-just-me-or-is-it-really-that-difficult/266872>\
**Category:** Beats\
**Tags:** filebeat\
**Created:** [March 11, 2021, 12:15am UTC](https://discuss.elastic.co/t/grok-is-it-just-me-or-is-it-really-that-difficult/266872 "2021-03-11T00:15:50Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![louis12356](https://avatars.discourse-cdn.com/v4/letter/l/ea5d25/32.png) [@louis12356](https://discuss.elastic.co/u/louis12356)\
**Post date:** [March 11, 2021, 12:15am UTC](https://discuss.elastic.co/t/grok-is-it-just-me-or-is-it-really-that-difficult/266872/1 "2021-03-11T00:15:50Z")

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Hey,

for some days now i try to figure out how to properly use grok to filter my logfiles.  
I use the classic? setup with filebeat as the input of logstash and elasticsearch and kibana for visualizing.

So far i managed to display some data in kibana explore; but my custom fields (which i defined? in grok) are always empty...

it also seems like, that only two of my logfiles are filtered (syslog and another one); but my server got like more then 20 different. The filebeat.yaml is set to /var/log/\* - so every file in there should be BEATEN to logstash.

My goal is to analyze access and error logs from apache as well from modsecurity; but particularly modsecurity log entries seem to be a mess to filter with grok.

Is there anyone out there who could share his grok filters or link a tutorial on how to properly configure grok? I tried so many ([kifarunix.com](http://kifarunix.com) and so on) but with no real success.

All field i get seem to be made by kibana itself and most of them only offer information about the target (host) but nothing about the client (agent).

Thank you in advance, Louis

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [April 8, 2021, 2:16am UTC](https://discuss.elastic.co/t/grok-is-it-just-me-or-is-it-really-that-difficult/266872/2 "2021-04-08T02:16:07Z")

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