You can add a custom counter very easily using ExecuteScript:
/* ECMAScript */
flowFile = session.get();
if (flowFile != null) {
session.adjustCounter("SampleScriptCounter", 1, false);
session.transfer(flowFile, REL_SUCCESS);
}
The performance may not be optimal, but you can experiment with counters
immediately.
Thanks,
James
On Fri, Dec 9, 2016 at 7:56 AM, Russell Bateman <[email protected]>
wrote:
> Aldrin,
>
> Forgive me for commandeering this thread.
>
> My down-streamers are asking for a custom "counting" processor because of
> what from their point of view is an unreliable volatility in the counts
> that the UI displays. In particular, they want to know how many documents
> they're feeding into our ETL flow and how many they're getting out (at
> least, in places where there is a one-to-one expectation which isn't all of
> our flows of course). The delta, which they are pretty sure to be non-zero,
> would be tantamount to lost/dropped documents. (So, they want me to
> manufacture the pistol they intend aiming at my head. ;-) )
>
> Are you saying that ProcessSession provides me, as a custom processor
> writer, the ability to do this (ostensibly in already existing custom
> processors I've written) in preference to adding yet another dedicated,
> custom processor?
>
> As new as NiFi is, great functionality is still hidden behind the fact
> that no one's using it and no one's writing about it, giving examples, etc.
> I was surprised to read this thread just now and wondered if it's another
> cool thing I've missed.
>
> Thanks for any confirmation, other comments, etc.
>
> Russ
>
> On 12/09/2016 08:42 AM, Aldrin Piri wrote:
>
>> Hello,
>>
>> Counters are a framework level item that allows processors to provide
>> counts on things whilst processing. This functionality must be exercised
>> via the ProcessSession[1] within a processor's code. To add one, you
>> would
>> need to invoke the adjustCounter method in your processor.
>>
>> [1]
>> https://github.com/apache/nifi/blob/master/nifi-api/src/main
>> /java/org/apache/nifi/processor/ProcessSession.java#L161
>>
>> On Fri, Dec 9, 2016 at 3:40 AM, bingogo1986 <[email protected]> wrote:
>>
>> hi
>>> I noticed 'Counter' button on top right of Nifi UI ，how to aad a
>>> specified
>>> counter ，thanks.
>>> Best regards.
>>>
>>
>
