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From Eduardo Fontes <eduardo.fon...@gmail.com>
Subject Re: Queue Prioritization
Date Mon, 02 Mar 2020 12:32:24 GMT
Hi Midhun,

I think this flow will do what you want.

[image: image.png]

Be advised that use of Wait/Notify will slow down the average throughput of
your flow because the aditional steps with the Cache.




On Sun, Mar 1, 2020 at 12:57 PM Midhun Mohan <midhun.mohan@esginc.us> wrote:

> So I would like to know your suggestions on how to implement wait and
> notify.
>
> In my case messages will flow one after another
>
> If a failure occurs I need to retry the failure before the orginal ones,
> and notify users if it fails again.
>
>
> On Sun, 1 Mar 2020, 6:31 pm Emanuel Oliveira, <emanueol@gmail.com> wrote:
>
> > Hi,
> >
> > Invokehttp have 4 exits
> > - success
> > - error retry -> loop/count retries (updateattribite) -> if retries > max
> > then logmessage(error) flow stops here ff discarded  Otherwise loop back
> to
> > invokehttp.
> > - error type 2 (bad password etc, )
> > - error type 3 (connectivity problems) you may want also to loop this one
> > with some delay , count retries and exit /log/stop after max.
> >
> > I just highly advise prior to invokehttp to have an updateattribute
> > deleting all attributes that don't start with some prefix.. to be sure
> your
> > ff looping doesnt keep adfing different errors, attributes wriiten by
> > invoke http.
> >
> > As good practice we prefix name all control attributes with flow_xxxxxxx
> so
> > our "cleanup," Updateattribute before Invokehttp have special regex sayng
> > "delete all attributes that don't start with flow_
> > (If you interested tomorrow when im back in office i csn share the regex
> a
> > bit tricky).
> >
> > Hope this helps, i just would love all processors to be as good as
> > invokehttp providing hard multipke exit points for specifics + all the
> nice
> > write attributes invokehttp adds that ptovide high details on errors or
> > success (atttibutes created/added by invokehttp to ff are prefixed with
> > invoke.xxxxx
> >
> > Cheers,
> > Emanuel O.
> >
> >
> >
> >
> >
> >
> > On Sun, 1 Mar 2020, 12:42 Midhun Mohan, <midhun.mohan@esginc.us> wrote:
> >
> > > Hi my use case is
> > >
> > > When a invokehttp processor fails I need to stop the incoming message
> and
> > > retry the failed message 2 times and if it is success start the
> execution
> > > normally or if it fails again need to notify admins and stop the main
> > > invoke http processor.
> > >
> > >
> > >
> > > Hope you can get the scenario from this
> > >
> > > On Sun, 1 Mar 2020, 5:30 pm Eduardo Fontes, <eduardo.fontes@gmail.com>
> > > wrote:
> > >
> > > > Hi Midhun,
> > > >
> > > > You can use DistributedMapCacheServer which starts a cache service
> > within
> > > > NiFi's process, but I not recommend in production. Instead you could
> > use
> > > > RedisConnectionPoolService.
> > > >
> > > > To use solution Wait/Notify the NiFi must know the number of
> flowfiles
> > to
> > > > process in one queue before start another queue. If it is a batch/on
> > > demand
> > > > flow I think it's easier. If it is a continuos/streamming flow you
> must
> > > > define a window, by number of flowfiles or by time, to switch between
> > > > queues.
> > > >
> > > > Please let me know what is your case.
> > > >
> > > > On Fri, Feb 28, 2020 at 2:39 PM Midhun Mohan <midhun.mohan@esginc.us
> >
> > > > wrote:
> > > >
> > > > > I think wait and notify can solve my problem. I checked the
> > documents ,
> > > > > which is bit unclear to me. Can anyone help me?
> > > > >
> > > > > Just to know few things like whether we need to configure a cache
> > > server,
> > > > > if so which one is best
> > > > > And also getting confused on how to configure wait and notify
> signals
> > > > >
> > > > > On Fri, 28 Feb 2020, 10:59 pm Eduardo Fontes, <
> > > eduardo.fontes@gmail.com>
> > > > > wrote:
> > > > >
> > > > > > Hi! Maybe you should try another approach, like Wait/Notify
or
> > > > configure
> > > > > > prioritizer just before the funnel, depending on your demand.
> > > > > >
> > > > > > On Fri, Feb 28, 2020 at 11:40 AM Midhun Mohan <
> > > midhun.mohan@esginc.us>
> > > > > > wrote:
> > > > > >
> > > > > > > Hi all,
> > > > > > > How to prioritize one queue before a funnel?
> > > > > > >
> > > > > > >  I need to make sure one queue is emptied before another
queue
> is
> > > > taken
> > > > > > > over for executing, I tried with a priority attribute but
it
> > fails
> > > > > when a
> > > > > > > queue with less priority has messages before the queue
with
> high
> > > > > > priority.
> > > > > > >
> > > > > > > --
> > > > > > >
> > > > > > >
> > > > > > > Regards,
> > > > > > > Midhun Mohan
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>

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