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From Paul Riddle <>
Subject Re: ValidateRecord Processor
Date Sun, 05 Nov 2017 20:53:34 GMT
Hi Mark!

Thanks for the fast response.  That does make sense.  Since I am not making
any modifications, just validating against a given schema, there is nothing
for the Record Writer to do.  I am still a little confused as to why it is
a required Property in the ValidateRecord processor, however.


On Sun, Nov 5, 2017 at 3:46 PM, Mark Payne <> wrote:

> Hey Paul,
> That is accurate - the Record Writer chosen will not affect the validation
> process.
> The way that the processor works is to read in records, one at a time,
> from a FlowFile.
> Once a record has been read, it is validated against the given schema. It
> is then written
> to either the 'valid' relationship or the 'invalid' relationship. When
> this happens, the chosen
> Record Writer is used to write it out.
> So it would be very common to have a CSV Reader with a CSV Writer or a
> JSON Reader
> with a JSON Writer, for instance. However, you could also configure a CSV
> Reader with
> a JSON Writer, and it will essentially convert the record for you inline.
> This is a very common pattern for the record-oriented processors, because
> the records are
> read in, parsed, and turned into a 'Record' object. Once this has
> happened, we can treat that
> Record object the same, whether it was parsed from a CSV file, a JSON
> file, or some custom
> format. This, of course, provides us with some very powerful, reusable
> processors! Once we've
> finished working with that Record object, though, we need to pass it on in
> some way. So we make
> use of a Record Writer to serialize it back out.
> Does that all make sense?
> Thanks
> -Mark
> On Nov 5, 2017, at 3:24 PM, Paul Riddle <> wrote:
> Hello All,
> In regards to the NiFi 1.4 ValidateRecord processor, it doesn't appear to
> matter what Record Writer I choose.  As long as the Record Reader can read
> the incoming flowfile and the Schema Access Strategy validates my flowfile,
> it comes out the "valid" relationship.
> Am I missing some other purpose for the Record Writer property in the
> ValidateRecord Processor?  If so I would like to understand it better.
> Regards,
> Paul
> <>
> <>

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