Stéphane,
Welcome to NiFi, glad to have you aboard! May I ask what version you
are using? I believe as of at least 0.6.0, you can view the items in a
queued connection. So for your example, you can have a GetHttp into a
SplitJson, but don't start the SplitJson, just the GetHttp. You will
see any flowfiles generated by GetHttp queued up in the success (or
response?) connection (whichever you have wired to SplitJson). Then
you can right-click on the connection (the line between the
processors) and choose List Queue. In that dialog you can choose an
element by clicking on the Info icon ('i' in a circle) and see the
information about it, including a View button for the content.
The best part is that you don't have to do a "preview" run, then a
"real" run. The data is in the connection's queue, so you can make
alterations to your SplitJson, then start it to see if it works. If it
doesn't, stop it and start the GetHttp again (if stopped) to put more
data in the queue. For fine-grained debugging, you can temporarily
set the Run schedule for the SplitJson to something like 10 seconds,
then when you start it, it will likely only bring in one flow file, so
you can react to how it works, then stop it before it empties the
queue.
I hope that makes sense, I apologize in advance if I made things more
confusing. The good news is there is a solution to your problem, even
if I am not the right person to describe it :)
Cheers,
Matt
On Thu, Apr 28, 2016 at 7:06 PM, Stéphane Maarek
<[email protected]> wrote:
> Hi,
>
> I'm very new to nifi and love the concept. As part of the process, I'm
> learning. My biggest frustration is that I can't see the data flowing
> through the system as I do development.
>
> Maybe I missed an article or a link, but is it possible to view the data
> while in the flow? I.e. Say I create a get http, I'd like it to fire once,
> get some data so I can see what it looks like. Then if I do a split json,
> I'd like to see if my output of it is what I expected or if I somehow messed
> up, etc etc
>
> I hope my question is clear
>
> Thanks in advance,
> Stéphane
