Nifi ExtractGrok Processor

[#1]

I've been slowly ramping up with Nifi, and am trying to find some information on the ExtractGrok processor. I can't seem to find any actual examples anywhere on it's use and everything I'm trying is failing.

Specifically, I can't figure out exactly what to provide for the grok Expression vs the grok Pattern file; they would seem to be the kind of thing you'd provide one or the other but it wants both.

I'm simply trying to pull a few fields out of a log message (and there may be better ways to do it long term) but I'm really curious about how to make this processor work.

Does anyone have a real example of it's use I could reference?

[#2 · Accepted solution]

There is also a GrokReader for record processors, and the additional details docs of that has the default pattern's it uses.

See the end of this page:

https://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi/nifi-record-serialization-services...