nifi-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Matt Burgess <>
Subject Re: Someone recommend a good Avro studdy guide for newbie?
Date Wed, 22 Nov 2017 21:28:47 GMT

If you're looking for examples on implementing a scripted record
reader/writer, you can see the unit test examples [1] or Drew Lim's
blog [2].  However I suspect you are looking to leverage an existing
RecordReader/Writer from a scripted processor such as ExecuteScript or
InvokeScriptedProcessor, to prototype a "record-aware" processor.  A
general approach is implemented in AbstractRecordProcessor[3], I don't
believe the NiFi Scripting NAR has access to that class, but you can
certainly copy-and-paste the relevant bits of code.  I don't think you
can (easily) get access to an existing RecordReader/Writer controller
service, but Mark Payne outlined the alternative in your mailing list
question about getting a DBCPService property. The recommended
approach is to use InvokeScriptedProcessor and specify your own
RecordReader/Writer properties which will be presented to the user in
the InvokeScriptedProcessor dialog (once the script has been applied).
Then you can get the RecordReader/Writer objects (see [3] lines
100-101) and use them in a similar way as [3].

This (and the answer(s) to your questions in the other mailing list
post) would make excellent blog posts/articles, I hope to do some
relatively soon, will keep the list posted :)



On Wed, Nov 22, 2017 at 3:00 PM, Eric Chaves <> wrote:
> Hi folks,
> Due to my lack of knowledge with Avro in my scripted processors I'm required
> to convert them to JSON in order to be able to manipulate them.
> I would like to avoid this and write record based processors but I have no
> clue about how should I do to actually read/write/modify record based
> content (including modifying underlying schemas).
> Do you have any reading material to recommend?
> Thanks in advance,
> Eric

View raw message