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Posted to users@nifi.apache.org by Bryan Bende <bb...@gmail.com> on 2017/10/04 14:40:29 UTC
Re: nifi 1.4 - variables
Hello,
You can use them in any fields that support expression language, just
like variables in a properties file
(nifi.variable.registry.properties= in nifi.properties) or system
properties in bootstrap.conf.
In the properties file approach you had to restart NiFi for any
changes in the properties to be picked up.
In the new approach you no longer need to restart anything yourself,
it will be handled for you.
-Bryan
On Wed, Oct 4, 2017 at 8:20 AM, Uwe Geercken <uw...@web.de> wrote:
> Hello,
>
> in 1.4 when you right-click the processor group then there is an entry
> "variables". I have defined some, but I wonder how I can use them.
>
> I have not found documentation on this. Does somebody have details or a
> link to documentation or an example?
>
> Rgds,
>
> Uwe
Re: nifi 1.4 - variables
Posted by Russell Bateman <ru...@windofkeltia.com>.
Can't say which is more useful--registry or variables, but I'm delighted
to have both now. The registry was already a huge step toward solving
problems of this sort. These variables are also very, very welcome! I
love the scope semantic that comes along with them.
--what Uwe said about NiFi. NiFi just rocks!
On 10/04/2017 09:45 AM, Uwe Geercken wrote:
> cool. I will check.
> I really like this - to get rid of the hardcoding of paths e.g.
> Nifi gets better and better.
> Rgds,
> Uwe
> *Gesendet:* Mittwoch, 04. Oktober 2017 um 17:39 Uhr
> *Von:* "Bryan Bende" <bb...@gmail.com>
> *An:* users@nifi.apache.org
> *Betreff:* Re: Re: nifi 1.4 - variables
> Thanks!
>
> There is a JIRA to add additional documentation to the user guide [1].
> For the previously existing capabilities with the properties file,
> there is some mention in the admin guide [2].
>
> The variables work in a hierarchical manner, meaning if a variable
> "foo" is declared at the root group and also declared inside a process
> group, components inside the process group will use the value of "foo"
> from within the process group.
>
> If you test this out, the UI should indicate which one is being
> used... In the above example, if you looked at the variables from
> within the process group, you should see "foo" listed twice, but the
> one from the root group would have a line through it indicating that
> it is being overridden.
>
> -Bryan
>
> [1] https://issues.apache.org/jira/browse/NIFI-4462
> [2]
> https://nifi.apache.org/docs/nifi-docs/html/administration-guide.html#custom_properties
>
>
> On Wed, Oct 4, 2017 at 11:26 AM, Uwe Geercken <uw...@web.de> wrote:
> > thank you Bryan.
> >
> > is there documentation around for the variables?
> >
> > If I add variables to the processor group and I want to reference a
> variable
> > of the parent flow, will I have to add the scope somehow like
> > ${scope.variable}?
> >
> > If I have variables in different hierarchies of the flow with the
> same name,
> > which one will be used?
> >
> >
> > P.S. I really like your blog :-)
> >
> > Rgds,
> >
> > Uwe
> >
> >
> > Gesendet: Mittwoch, 04. Oktober 2017 um 16:40 Uhr
> > Von: "Bryan Bende" <bb...@gmail.com>
> > An: users@nifi.apache.org
> > Betreff: Re: nifi 1.4 - variables
> > Hello,
> >
> > You can use them in any fields that support expression language, just
> > like variables in a properties file
> > (nifi.variable.registry.properties= in nifi.properties) or system
> > properties in bootstrap.conf.
> >
> > In the properties file approach you had to restart NiFi for any
> > changes in the properties to be picked up.
> >
> > In the new approach you no longer need to restart anything yourself,
> > it will be handled for you.
> >
> > -Bryan
> >
> > On Wed, Oct 4, 2017 at 8:20 AM, Uwe Geercken <uw...@web.de>
> wrote:
> >> Hello,
> >>
> >> in 1.4 when you right-click the processor group then there is an entry
> >> "variables". I have defined some, but I wonder how I can use them.
> >>
> >> I have not found documentation on this. Does somebody have details or a
> >> link to documentation or an example?
> >>
> >> Rgds,
> >>
> >> Uwe
Re: Re: nifi 1.4 - variables
Posted by Bryan Bende <bb...@gmail.com>.
Thanks!
There is a JIRA to add additional documentation to the user guide [1].
For the previously existing capabilities with the properties file,
there is some mention in the admin guide [2].
The variables work in a hierarchical manner, meaning if a variable
"foo" is declared at the root group and also declared inside a process
group, components inside the process group will use the value of "foo"
from within the process group.
If you test this out, the UI should indicate which one is being
used... In the above example, if you looked at the variables from
within the process group, you should see "foo" listed twice, but the
one from the root group would have a line through it indicating that
it is being overridden.
-Bryan
[1] https://issues.apache.org/jira/browse/NIFI-4462
[2] https://nifi.apache.org/docs/nifi-docs/html/administration-guide.html#custom_properties
On Wed, Oct 4, 2017 at 11:26 AM, Uwe Geercken <uw...@web.de> wrote:
> thank you Bryan.
>
> is there documentation around for the variables?
>
> If I add variables to the processor group and I want to reference a variable
> of the parent flow, will I have to add the scope somehow like
> ${scope.variable}?
>
> If I have variables in different hierarchies of the flow with the same name,
> which one will be used?
>
>
> P.S. I really like your blog :-)
>
> Rgds,
>
> Uwe
>
>
> Gesendet: Mittwoch, 04. Oktober 2017 um 16:40 Uhr
> Von: "Bryan Bende" <bb...@gmail.com>
> An: users@nifi.apache.org
> Betreff: Re: nifi 1.4 - variables
> Hello,
>
> You can use them in any fields that support expression language, just
> like variables in a properties file
> (nifi.variable.registry.properties= in nifi.properties) or system
> properties in bootstrap.conf.
>
> In the properties file approach you had to restart NiFi for any
> changes in the properties to be picked up.
>
> In the new approach you no longer need to restart anything yourself,
> it will be handled for you.
>
> -Bryan
>
> On Wed, Oct 4, 2017 at 8:20 AM, Uwe Geercken <uw...@web.de> wrote:
>> Hello,
>>
>> in 1.4 when you right-click the processor group then there is an entry
>> "variables". I have defined some, but I wonder how I can use them.
>>
>> I have not found documentation on this. Does somebody have details or a
>> link to documentation or an example?
>>
>> Rgds,
>>
>> Uwe