Hi Peter, I think I have done similar thing before. This flow template may be useful in your case, too. https://gist.github.com/ijokarumawak/9e1a4855934f2bb9661f88ca625bd244
Thanks, Koji On Tue, Nov 14, 2017 at 12:58 PM, Peter Wicks (pwicks) <pwi...@micron.com> wrote: > Matt, > > I played around with your idea. I haven't been able to get it to work. > > First flow file comes in, goes out the wait relationship. Now how do we stop > the next FlowFile from going out the wait relationship and entering the flow? > Well we'd have to use Notify along with some scheduling on Wait so multiple > FlowFile's don't come through right away; so I put a Notify processor right > after Wait. Now the second FlowFile enters, goes out the success relationship > because there is a signal count, then immediately goes down wait since the > signal is clear... > > If this use case seems common enough, I was thinking that the solution might > be to have add an option on Wait that lets you choose whether you want to > "Wait for signal" or "Wait only if signaled". This would restore the > relationships back to their proper uses. Then you'd use the Notify property > 'Signal Counter Delta' mode of 0 at the end of the flow. Flow would be > something like Wait (Wait only if signaled)->Notify (Signal to 1)->... > Processors ...->Notify (Signal to 0). Or perhaps as part of the feature, > "Wait only if signaled" mode would do the notify step internally. > > Would still like to find a clean/easy way to do this though. > > Thanks, > Peter > > -----Original Message----- > From: Matt Burgess [mailto:mattyb...@apache.org] > Sent: Tuesday, November 14, 2017 08:53 > To: users@nifi.apache.org > Subject: [EXT] Re: Wait only if flagged? > > Peter, > > I haven't tried this, but my knee-jerk reaction is to switch the roles > of the "wait" and "success" relationships. Maybe you can send the > "wait" relationship downstream and route the "success" one back to > Wait. Then when the flag is "cleared", the flow files will start going > to the "success" relationship which is routed back to wait. > > Regards, > Matt > > On Mon, Nov 13, 2017 at 7:21 PM, Peter Wicks (pwicks) <pwi...@micron.com> > wrote: >> I have a database flow, which is a sequence of 4 processors. For database >> performance reasons I need to make sure only one file is in this section of >> the flow at a time. Not just one file per queue/processor, but for the whole >> section. >> >> >> >> I feel like I should be able to use Wait/Notify to do this, but Wait/Notify >> seem to do the opposite. I want to allow a file to go into the flow unless >> there is a flag. If there is a flag I want the FlowFile to wait until the >> flag is cleared. >> >> >> >> Thoughts? >> >> >> >> Thanks, >> >> Peter
