Thanks a lot everyone! On Fri, Apr 29, 2016, 10:02 AM Joe Percivall <joeperciv...@yahoo.com> wrote:
> Hello Stéphane, > > Just adding on to Matt's and Andy's answers, Andy mentioned Provenance[1] > for replaying events but I also find it very useful for debugging > processors/flows as well. Data Provenance is a core feature of NiFi and it > allows you to see exactly what the FlowFile looked like (attributes and > content) before and after a processor acted on it as well as the ability to > see a map of the journey that FlowFile underwent through your flow. The > easiest way to see the provenance of a processor is to right click on it > and then click "Data provenance". > > The documentation below should be a great introduction and if you have any > questions feel free to ask! > > [1] > https://nifi.apache.org/docs/nifi-docs/html/user-guide.html#data-provenance > > > Joe > - - - - - - > Joseph Percivall > linkedin.com/in/Percivall > e: joeperciv...@yahoo.com > > > > On Thursday, April 28, 2016 7:30 PM, Matt Burgess <mattyb...@gmail.com> > wrote: > > > > 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 > <stephane.maa...@gmail.com> 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 >
