The extractor is built using grok patterns. It is necessary to add the date format YYYY/MM/DD to Graylog’s library of stored patterns in order for the extractor to work.
- go to System → Grok Patterns → Import pattern file
- select grok-pattern.txt and press OK
- then go to your input and select “Manage extractors”
- click Actions → Import extractor
- paste the content of the extractor.txt file
If you like you can add rules to restrict execution of this extractor to certain occurrences of strings or other criteria.