Not sure why but all my GROK patterns show twice. Its entirely possible I imported the same set twice. I can see a delete button to the right of each pattern but that would take me hours, is there a quick way?
You can drop the “grok_patterns” collection in MongoDB and re-import your patterns.
FWIW, if there really are duplicate Grok patterns, this is a bug. In this case please create a bug report at https://github.com/Graylog2/graylog2-server/issues.
Hello,
I have exactly the same issue: https://community.graylog.org/t/grok-patterns-defined-twice/3162
I am sure I have never clicked on Apply Content Pack.
I think in my case duplicate entries came from the Graylog update.
I saw your thread but it was closed so I opened my own 

