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Posted to users@nifi.apache.org by James McMahon <js...@gmail.com> on 2018/04/13 18:37:34 UTC
Error in Jython environment
Good afternoon. I am running a python script from an ExecuteScript
processor in NiFi 0.7.1.c. I'm assuming this is actually running in a
Jython environment under the hood of the processor.
General question: How can I tell what version of Jython i am employing?
Specific problem: I employ an os.statvfs call to check available capacity
on my disk devices that host my content repo, and that host my data landing
zone. In my command line environment - not jython - Python has this library
and so I can successfully make this call.
In NiFi, I get this error at run time:
javax.script.ScriptException: AttributeError: 'module' object has no
attribute ;statvfs'
How can I correct this? I am happy to replace it if necessary with
something Jython provides, but don't fully understand the Jython
environment within NiFi. Is there a suitable Jython equivalent to fix this
problem? What package or module must i include in my script to get at that?
Thanks in advance for your help.
Jim
Re: Error in Jython environment
Posted by Matt Burgess <ma...@apache.org>.
Jim,
Just to confirm Joe's comments, we were using 2.7.0 but then bumped it
up to 2.7.1 as there was at least one method os.getpid() that hadn't
been implemented [1]. However, 2.7.1 apparently has multithreading
issues [2] that are causing some folks headaches as well.
Regards,
Matt
[1] https://issues.apache.org/jira/browse/NIFI-4301
[2] http://bugs.jython.org/issue2642
On Fri, Apr 13, 2018 at 2:59 PM, Joe Witt <jo...@gmail.com> wrote:
> Independent of NiFi have you successfully used any version of Jython
> to make that call?
>
> With the NiFi 1.x line that processor has been updated a little bit
> and in particular i think we have Jython 2.7.1 (off memory so could be
> totally nonsense) where as before we had 2.7.0 or something older...
>
> Thanks
>
> On Fri, Apr 13, 2018 at 6:37 PM, James McMahon <js...@gmail.com> wrote:
>> Good afternoon. I am running a python script from an ExecuteScript processor
>> in NiFi 0.7.1.c. I'm assuming this is actually running in a Jython
>> environment under the hood of the processor.
>>
>> General question: How can I tell what version of Jython i am employing?
>>
>> Specific problem: I employ an os.statvfs call to check available capacity on
>> my disk devices that host my content repo, and that host my data landing
>> zone. In my command line environment - not jython - Python has this library
>> and so I can successfully make this call.
>>
>> In NiFi, I get this error at run time:
>>
>> javax.script.ScriptException: AttributeError: 'module' object has no
>> attribute ;statvfs'
>>
>> How can I correct this? I am happy to replace it if necessary with something
>> Jython provides, but don't fully understand the Jython environment within
>> NiFi. Is there a suitable Jython equivalent to fix this problem? What
>> package or module must i include in my script to get at that?
>>
>> Thanks in advance for your help.
>>
>> Jim
Re: Error in Jython environment
Posted by James McMahon <js...@gmail.com>.
Thank you all for your insights. I opted to drop back and take a slightly
different approach, since statvfs was problematic.I created a pyt... a
jython function that employs subprocess.Popen against an argument I pass in
for deviceToCheck. My NiFi jython environment seems to allow the
subprocess.Popen. Not sure too many folks have the requirement to check
device usage before running a workflow, but in case you do this is an
inelegant but effective means to get the info:
deviceToCheck = 'content_repo'
In the function:
p1 = subprocess.Popen(["df","-hk"],stdout=subprocess.PIPE)
next_command = ["egrep",
"{}".format(deviceToCheck)]
p2 =subprocess.Popen(next_command, stdin=p1.stdout,stdout=subprocess.PIPE)
p1.stdout.close()
result = (p2.communicate()[0]).split()[-2].translate(None,'%')
p2.stdout.close()
I then compare this to my minimum capacity required threshold and return a
True or a False.
Thanks again for your assistance. -Jim
On Mon, Apr 16, 2018 at 9:27 AM, Mike Thomsen <mi...@gmail.com>
wrote:
> James,
>
> The reason you can't use "Python" is because the scripting bundle only
> works with JVM-based scripting languages like JRuby, Jython and Groovy.
> Java 6 introduced javax.script which is a package that adds a standard API
> for calling JVM scripting languages from a Java app.
>
> From from overcomplicating it, this is what simplifies the support for
> multiple scripting languages without getting into solutions like Py4j or
> doing weird things with inter-process communication like the Python API for
> Storm.
>
> On Sun, Apr 15, 2018 at 8:35 AM James McMahon <js...@gmail.com>
> wrote:
>
>> I'm not sure I understand. The ExecuteScript processor forces me into a
>> Jython environment - despite selecting Python as the scripting language in
>> the processor configuration. I'll never understand why that route was opted
>> for in the first place. Why overcomplicate this, introducing yet another
>> dependency (on Jython)? Let the selection of python as the script language
>> use the installed python on my server, and decouple me from any Jython
>> dependencies. It's been nothing but trouble. Python code that works just
>> fine from the command line fails for all manner of issues with Jython when
>> I call it from ExecuteScript.
>>
>> I gather you've called Flask-driven python microservices from NiFi. What
>> NiFi processor allows you to do that? I'll look into Flask-driven
>> microservices now, and am certainly willing to try this. Thanks very much.
>>
>> On Sat, Apr 14, 2018 at 12:25 PM, Mike Thomsen <mi...@gmail.com>
>> wrote:
>>
>>> From a lot of your posts, it seems like you're running into the same
>>> sort of problem that some of my colleagues ran into with Jython. The fact
>>> is that Jython is just not well supported by the Python community, and it's
>>> going to keep getting worse as Python 2.X EOL deadline in 2020 (IIRC) gets
>>> closer. As a Python developer, I think you might find it a lot easier to
>>> switch to Python 3 for your code and turn these scripts into Flask-driven
>>> microservices that are called by NiFi.
>>>
>>> Mike
>>>
>>> On Fri, Apr 13, 2018 at 5:47 PM James McMahon <js...@gmail.com>
>>> wrote:
>>>
>>>> No sir. When I run from the command line - I encapsulate
>>>> script-specific command sequences in code triggered by SCRIPT var value,
>>>> and NiFi sequences encapsulated within NIFI var values - it runs in a
>>>> Python environment. I attempted jython -V at the command line, and it was
>>>> unable to find an installation of jython independent of that which comes
>>>> embedded in NiFi 0.7.1.c.
>>>>
>>>> Assuming that I am operating in a Jython 2.7.0 environment when in
>>>> NiFi, are there specific libraries or packages I should import to get it to
>>>> recognize what seem to be very fundamental os package commands? Is it
>>>> possible to override the use of the jython packages that I suspect are
>>>> missing, and force it to use the python packages that I know are there?
>>>>
>>>> If I must abandon os.statvfs to get this to work in NiFi, have you seen
>>>> anyone harvest disk usage information from any native NiFi processors? My
>>>> thinking is this: if I can't climb the Jython mountain, maybe I can precede
>>>> my ExecuteScript processor with something that does this check in advance.
>>>> I would then rip these calls out of my python script (NIFI sections).
>>>>
>>>> Jim
>>>>
>>>> On Fri, Apr 13, 2018 at 2:59 PM, Joe Witt <jo...@gmail.com> wrote:
>>>>
>>>>> Independent of NiFi have you successfully used any version of Jython
>>>>> to make that call?
>>>>>
>>>>> With the NiFi 1.x line that processor has been updated a little bit
>>>>> and in particular i think we have Jython 2.7.1 (off memory so could be
>>>>> totally nonsense) where as before we had 2.7.0 or something older...
>>>>>
>>>>> Thanks
>>>>>
>>>>> On Fri, Apr 13, 2018 at 6:37 PM, James McMahon <js...@gmail.com>
>>>>> wrote:
>>>>> > Good afternoon. I am running a python script from an ExecuteScript
>>>>> processor
>>>>> > in NiFi 0.7.1.c. I'm assuming this is actually running in a Jython
>>>>> > environment under the hood of the processor.
>>>>> >
>>>>> > General question: How can I tell what version of Jython i am
>>>>> employing?
>>>>> >
>>>>> > Specific problem: I employ an os.statvfs call to check available
>>>>> capacity on
>>>>> > my disk devices that host my content repo, and that host my data
>>>>> landing
>>>>> > zone. In my command line environment - not jython - Python has this
>>>>> library
>>>>> > and so I can successfully make this call.
>>>>> >
>>>>> > In NiFi, I get this error at run time:
>>>>> >
>>>>> > javax.script.ScriptException: AttributeError: 'module' object has no
>>>>> > attribute ;statvfs'
>>>>> >
>>>>> > How can I correct this? I am happy to replace it if necessary with
>>>>> something
>>>>> > Jython provides, but don't fully understand the Jython environment
>>>>> within
>>>>> > NiFi. Is there a suitable Jython equivalent to fix this problem? What
>>>>> > package or module must i include in my script to get at that?
>>>>> >
>>>>> > Thanks in advance for your help.
>>>>> >
>>>>> > Jim
>>>>>
>>>>
>>
Re: Error in Jython environment
Posted by Mike Thomsen <mi...@gmail.com>.
James,
The reason you can't use "Python" is because the scripting bundle only
works with JVM-based scripting languages like JRuby, Jython and Groovy.
Java 6 introduced javax.script which is a package that adds a standard API
for calling JVM scripting languages from a Java app.
From from overcomplicating it, this is what simplifies the support for
multiple scripting languages without getting into solutions like Py4j or
doing weird things with inter-process communication like the Python API for
Storm.
On Sun, Apr 15, 2018 at 8:35 AM James McMahon <js...@gmail.com> wrote:
> I'm not sure I understand. The ExecuteScript processor forces me into a
> Jython environment - despite selecting Python as the scripting language in
> the processor configuration. I'll never understand why that route was opted
> for in the first place. Why overcomplicate this, introducing yet another
> dependency (on Jython)? Let the selection of python as the script language
> use the installed python on my server, and decouple me from any Jython
> dependencies. It's been nothing but trouble. Python code that works just
> fine from the command line fails for all manner of issues with Jython when
> I call it from ExecuteScript.
>
> I gather you've called Flask-driven python microservices from NiFi. What
> NiFi processor allows you to do that? I'll look into Flask-driven
> microservices now, and am certainly willing to try this. Thanks very much.
>
> On Sat, Apr 14, 2018 at 12:25 PM, Mike Thomsen <mi...@gmail.com>
> wrote:
>
>> From a lot of your posts, it seems like you're running into the same sort
>> of problem that some of my colleagues ran into with Jython. The fact is
>> that Jython is just not well supported by the Python community, and it's
>> going to keep getting worse as Python 2.X EOL deadline in 2020 (IIRC) gets
>> closer. As a Python developer, I think you might find it a lot easier to
>> switch to Python 3 for your code and turn these scripts into Flask-driven
>> microservices that are called by NiFi.
>>
>> Mike
>>
>> On Fri, Apr 13, 2018 at 5:47 PM James McMahon <js...@gmail.com>
>> wrote:
>>
>>> No sir. When I run from the command line - I encapsulate script-specific
>>> command sequences in code triggered by SCRIPT var value, and NiFi
>>> sequences encapsulated within NIFI var values - it runs in a Python
>>> environment. I attempted jython -V at the command line, and it was unable
>>> to find an installation of jython independent of that which comes embedded
>>> in NiFi 0.7.1.c.
>>>
>>> Assuming that I am operating in a Jython 2.7.0 environment when in NiFi,
>>> are there specific libraries or packages I should import to get it to
>>> recognize what seem to be very fundamental os package commands? Is it
>>> possible to override the use of the jython packages that I suspect are
>>> missing, and force it to use the python packages that I know are there?
>>>
>>> If I must abandon os.statvfs to get this to work in NiFi, have you seen
>>> anyone harvest disk usage information from any native NiFi processors? My
>>> thinking is this: if I can't climb the Jython mountain, maybe I can precede
>>> my ExecuteScript processor with something that does this check in advance.
>>> I would then rip these calls out of my python script (NIFI sections).
>>>
>>> Jim
>>>
>>> On Fri, Apr 13, 2018 at 2:59 PM, Joe Witt <jo...@gmail.com> wrote:
>>>
>>>> Independent of NiFi have you successfully used any version of Jython
>>>> to make that call?
>>>>
>>>> With the NiFi 1.x line that processor has been updated a little bit
>>>> and in particular i think we have Jython 2.7.1 (off memory so could be
>>>> totally nonsense) where as before we had 2.7.0 or something older...
>>>>
>>>> Thanks
>>>>
>>>> On Fri, Apr 13, 2018 at 6:37 PM, James McMahon <js...@gmail.com>
>>>> wrote:
>>>> > Good afternoon. I am running a python script from an ExecuteScript
>>>> processor
>>>> > in NiFi 0.7.1.c. I'm assuming this is actually running in a Jython
>>>> > environment under the hood of the processor.
>>>> >
>>>> > General question: How can I tell what version of Jython i am
>>>> employing?
>>>> >
>>>> > Specific problem: I employ an os.statvfs call to check available
>>>> capacity on
>>>> > my disk devices that host my content repo, and that host my data
>>>> landing
>>>> > zone. In my command line environment - not jython - Python has this
>>>> library
>>>> > and so I can successfully make this call.
>>>> >
>>>> > In NiFi, I get this error at run time:
>>>> >
>>>> > javax.script.ScriptException: AttributeError: 'module' object has no
>>>> > attribute ;statvfs'
>>>> >
>>>> > How can I correct this? I am happy to replace it if necessary with
>>>> something
>>>> > Jython provides, but don't fully understand the Jython environment
>>>> within
>>>> > NiFi. Is there a suitable Jython equivalent to fix this problem? What
>>>> > package or module must i include in my script to get at that?
>>>> >
>>>> > Thanks in advance for your help.
>>>> >
>>>> > Jim
>>>>
>>>
>
Re: Error in Jython environment
Posted by Boris Tyukin <bo...@boristyukin.com>.
Hi James,
Another new nifi user and Python fan here.
Nifi runs in a single jvm instance and it has limited options talking to
other languages like Python. Apache Spark took another road, using py4j,
which I think is a better idea, rather than using jython. But in the end of
the day, jython is what you have.
Like you, I wanted to use Python, but quickly realized NiFi's limitations.
The big deal for me was performance and the fact I cannot use Java
libraries and complied Python packages.
Fortunately, I discovered that groovy was very easy to learn and I was able
to grasp basics needed for my simple scripts in a few hours. There are also
tons of examples how to use groovy with nifi.
Boris
On Sun, Apr 15, 2018, 08:35 James McMahon <js...@gmail.com> wrote:
> I'm not sure I understand. The ExecuteScript processor forces me into a
> Jython environment - despite selecting Python as the scripting language in
> the processor configuration. I'll never understand why that route was opted
> for in the first place. Why overcomplicate this, introducing yet another
> dependency (on Jython)? Let the selection of python as the script language
> use the installed python on my server, and decouple me from any Jython
> dependencies. It's been nothing but trouble. Python code that works just
> fine from the command line fails for all manner of issues with Jython when
> I call it from ExecuteScript.
>
> I gather you've called Flask-driven python microservices from NiFi. What
> NiFi processor allows you to do that? I'll look into Flask-driven
> microservices now, and am certainly willing to try this. Thanks very much.
>
> On Sat, Apr 14, 2018 at 12:25 PM, Mike Thomsen <mi...@gmail.com>
> wrote:
>
>> From a lot of your posts, it seems like you're running into the same sort
>> of problem that some of my colleagues ran into with Jython. The fact is
>> that Jython is just not well supported by the Python community, and it's
>> going to keep getting worse as Python 2.X EOL deadline in 2020 (IIRC) gets
>> closer. As a Python developer, I think you might find it a lot easier to
>> switch to Python 3 for your code and turn these scripts into Flask-driven
>> microservices that are called by NiFi.
>>
>> Mike
>>
>> On Fri, Apr 13, 2018 at 5:47 PM James McMahon <js...@gmail.com>
>> wrote:
>>
>>> No sir. When I run from the command line - I encapsulate script-specific
>>> command sequences in code triggered by SCRIPT var value, and NiFi
>>> sequences encapsulated within NIFI var values - it runs in a Python
>>> environment. I attempted jython -V at the command line, and it was unable
>>> to find an installation of jython independent of that which comes embedded
>>> in NiFi 0.7.1.c.
>>>
>>> Assuming that I am operating in a Jython 2.7.0 environment when in NiFi,
>>> are there specific libraries or packages I should import to get it to
>>> recognize what seem to be very fundamental os package commands? Is it
>>> possible to override the use of the jython packages that I suspect are
>>> missing, and force it to use the python packages that I know are there?
>>>
>>> If I must abandon os.statvfs to get this to work in NiFi, have you seen
>>> anyone harvest disk usage information from any native NiFi processors? My
>>> thinking is this: if I can't climb the Jython mountain, maybe I can precede
>>> my ExecuteScript processor with something that does this check in advance.
>>> I would then rip these calls out of my python script (NIFI sections).
>>>
>>> Jim
>>>
>>> On Fri, Apr 13, 2018 at 2:59 PM, Joe Witt <jo...@gmail.com> wrote:
>>>
>>>> Independent of NiFi have you successfully used any version of Jython
>>>> to make that call?
>>>>
>>>> With the NiFi 1.x line that processor has been updated a little bit
>>>> and in particular i think we have Jython 2.7.1 (off memory so could be
>>>> totally nonsense) where as before we had 2.7.0 or something older...
>>>>
>>>> Thanks
>>>>
>>>> On Fri, Apr 13, 2018 at 6:37 PM, James McMahon <js...@gmail.com>
>>>> wrote:
>>>> > Good afternoon. I am running a python script from an ExecuteScript
>>>> processor
>>>> > in NiFi 0.7.1.c. I'm assuming this is actually running in a Jython
>>>> > environment under the hood of the processor.
>>>> >
>>>> > General question: How can I tell what version of Jython i am
>>>> employing?
>>>> >
>>>> > Specific problem: I employ an os.statvfs call to check available
>>>> capacity on
>>>> > my disk devices that host my content repo, and that host my data
>>>> landing
>>>> > zone. In my command line environment - not jython - Python has this
>>>> library
>>>> > and so I can successfully make this call.
>>>> >
>>>> > In NiFi, I get this error at run time:
>>>> >
>>>> > javax.script.ScriptException: AttributeError: 'module' object has no
>>>> > attribute ;statvfs'
>>>> >
>>>> > How can I correct this? I am happy to replace it if necessary with
>>>> something
>>>> > Jython provides, but don't fully understand the Jython environment
>>>> within
>>>> > NiFi. Is there a suitable Jython equivalent to fix this problem? What
>>>> > package or module must i include in my script to get at that?
>>>> >
>>>> > Thanks in advance for your help.
>>>> >
>>>> > Jim
>>>>
>>>
>
Re: Error in Jython environment
Posted by James McMahon <js...@gmail.com>.
I'm not sure I understand. The ExecuteScript processor forces me into a
Jython environment - despite selecting Python as the scripting language in
the processor configuration. I'll never understand why that route was opted
for in the first place. Why overcomplicate this, introducing yet another
dependency (on Jython)? Let the selection of python as the script language
use the installed python on my server, and decouple me from any Jython
dependencies. It's been nothing but trouble. Python code that works just
fine from the command line fails for all manner of issues with Jython when
I call it from ExecuteScript.
I gather you've called Flask-driven python microservices from NiFi. What
NiFi processor allows you to do that? I'll look into Flask-driven
microservices now, and am certainly willing to try this. Thanks very much.
On Sat, Apr 14, 2018 at 12:25 PM, Mike Thomsen <mi...@gmail.com>
wrote:
> From a lot of your posts, it seems like you're running into the same sort
> of problem that some of my colleagues ran into with Jython. The fact is
> that Jython is just not well supported by the Python community, and it's
> going to keep getting worse as Python 2.X EOL deadline in 2020 (IIRC) gets
> closer. As a Python developer, I think you might find it a lot easier to
> switch to Python 3 for your code and turn these scripts into Flask-driven
> microservices that are called by NiFi.
>
> Mike
>
> On Fri, Apr 13, 2018 at 5:47 PM James McMahon <js...@gmail.com>
> wrote:
>
>> No sir. When I run from the command line - I encapsulate script-specific
>> command sequences in code triggered by SCRIPT var value, and NiFi
>> sequences encapsulated within NIFI var values - it runs in a Python
>> environment. I attempted jython -V at the command line, and it was unable
>> to find an installation of jython independent of that which comes embedded
>> in NiFi 0.7.1.c.
>>
>> Assuming that I am operating in a Jython 2.7.0 environment when in NiFi,
>> are there specific libraries or packages I should import to get it to
>> recognize what seem to be very fundamental os package commands? Is it
>> possible to override the use of the jython packages that I suspect are
>> missing, and force it to use the python packages that I know are there?
>>
>> If I must abandon os.statvfs to get this to work in NiFi, have you seen
>> anyone harvest disk usage information from any native NiFi processors? My
>> thinking is this: if I can't climb the Jython mountain, maybe I can precede
>> my ExecuteScript processor with something that does this check in advance.
>> I would then rip these calls out of my python script (NIFI sections).
>>
>> Jim
>>
>> On Fri, Apr 13, 2018 at 2:59 PM, Joe Witt <jo...@gmail.com> wrote:
>>
>>> Independent of NiFi have you successfully used any version of Jython
>>> to make that call?
>>>
>>> With the NiFi 1.x line that processor has been updated a little bit
>>> and in particular i think we have Jython 2.7.1 (off memory so could be
>>> totally nonsense) where as before we had 2.7.0 or something older...
>>>
>>> Thanks
>>>
>>> On Fri, Apr 13, 2018 at 6:37 PM, James McMahon <js...@gmail.com>
>>> wrote:
>>> > Good afternoon. I am running a python script from an ExecuteScript
>>> processor
>>> > in NiFi 0.7.1.c. I'm assuming this is actually running in a Jython
>>> > environment under the hood of the processor.
>>> >
>>> > General question: How can I tell what version of Jython i am employing?
>>> >
>>> > Specific problem: I employ an os.statvfs call to check available
>>> capacity on
>>> > my disk devices that host my content repo, and that host my data
>>> landing
>>> > zone. In my command line environment - not jython - Python has this
>>> library
>>> > and so I can successfully make this call.
>>> >
>>> > In NiFi, I get this error at run time:
>>> >
>>> > javax.script.ScriptException: AttributeError: 'module' object has no
>>> > attribute ;statvfs'
>>> >
>>> > How can I correct this? I am happy to replace it if necessary with
>>> something
>>> > Jython provides, but don't fully understand the Jython environment
>>> within
>>> > NiFi. Is there a suitable Jython equivalent to fix this problem? What
>>> > package or module must i include in my script to get at that?
>>> >
>>> > Thanks in advance for your help.
>>> >
>>> > Jim
>>>
>>
Re: Error in Jython environment
Posted by Mike Thomsen <mi...@gmail.com>.
From a lot of your posts, it seems like you're running into the same sort
of problem that some of my colleagues ran into with Jython. The fact is
that Jython is just not well supported by the Python community, and it's
going to keep getting worse as Python 2.X EOL deadline in 2020 (IIRC) gets
closer. As a Python developer, I think you might find it a lot easier to
switch to Python 3 for your code and turn these scripts into Flask-driven
microservices that are called by NiFi.
Mike
On Fri, Apr 13, 2018 at 5:47 PM James McMahon <js...@gmail.com> wrote:
> No sir. When I run from the command line - I encapsulate script-specific
> command sequences in code triggered by SCRIPT var value, and NiFi
> sequences encapsulated within NIFI var values - it runs in a Python
> environment. I attempted jython -V at the command line, and it was unable
> to find an installation of jython independent of that which comes embedded
> in NiFi 0.7.1.c.
>
> Assuming that I am operating in a Jython 2.7.0 environment when in NiFi,
> are there specific libraries or packages I should import to get it to
> recognize what seem to be very fundamental os package commands? Is it
> possible to override the use of the jython packages that I suspect are
> missing, and force it to use the python packages that I know are there?
>
> If I must abandon os.statvfs to get this to work in NiFi, have you seen
> anyone harvest disk usage information from any native NiFi processors? My
> thinking is this: if I can't climb the Jython mountain, maybe I can precede
> my ExecuteScript processor with something that does this check in advance.
> I would then rip these calls out of my python script (NIFI sections).
>
> Jim
>
> On Fri, Apr 13, 2018 at 2:59 PM, Joe Witt <jo...@gmail.com> wrote:
>
>> Independent of NiFi have you successfully used any version of Jython
>> to make that call?
>>
>> With the NiFi 1.x line that processor has been updated a little bit
>> and in particular i think we have Jython 2.7.1 (off memory so could be
>> totally nonsense) where as before we had 2.7.0 or something older...
>>
>> Thanks
>>
>> On Fri, Apr 13, 2018 at 6:37 PM, James McMahon <js...@gmail.com>
>> wrote:
>> > Good afternoon. I am running a python script from an ExecuteScript
>> processor
>> > in NiFi 0.7.1.c. I'm assuming this is actually running in a Jython
>> > environment under the hood of the processor.
>> >
>> > General question: How can I tell what version of Jython i am employing?
>> >
>> > Specific problem: I employ an os.statvfs call to check available
>> capacity on
>> > my disk devices that host my content repo, and that host my data landing
>> > zone. In my command line environment - not jython - Python has this
>> library
>> > and so I can successfully make this call.
>> >
>> > In NiFi, I get this error at run time:
>> >
>> > javax.script.ScriptException: AttributeError: 'module' object has no
>> > attribute ;statvfs'
>> >
>> > How can I correct this? I am happy to replace it if necessary with
>> something
>> > Jython provides, but don't fully understand the Jython environment
>> within
>> > NiFi. Is there a suitable Jython equivalent to fix this problem? What
>> > package or module must i include in my script to get at that?
>> >
>> > Thanks in advance for your help.
>> >
>> > Jim
>>
>
Re: Error in Jython environment
Posted by James McMahon <js...@gmail.com>.
No sir. When I run from the command line - I encapsulate script-specific
command sequences in code triggered by SCRIPT var value, and NiFi
sequences encapsulated within NIFI var values - it runs in a Python
environment. I attempted jython -V at the command line, and it was unable
to find an installation of jython independent of that which comes embedded
in NiFi 0.7.1.c.
Assuming that I am operating in a Jython 2.7.0 environment when in NiFi,
are there specific libraries or packages I should import to get it to
recognize what seem to be very fundamental os package commands? Is it
possible to override the use of the jython packages that I suspect are
missing, and force it to use the python packages that I know are there?
If I must abandon os.statvfs to get this to work in NiFi, have you seen
anyone harvest disk usage information from any native NiFi processors? My
thinking is this: if I can't climb the Jython mountain, maybe I can precede
my ExecuteScript processor with something that does this check in advance.
I would then rip these calls out of my python script (NIFI sections).
Jim
On Fri, Apr 13, 2018 at 2:59 PM, Joe Witt <jo...@gmail.com> wrote:
> Independent of NiFi have you successfully used any version of Jython
> to make that call?
>
> With the NiFi 1.x line that processor has been updated a little bit
> and in particular i think we have Jython 2.7.1 (off memory so could be
> totally nonsense) where as before we had 2.7.0 or something older...
>
> Thanks
>
> On Fri, Apr 13, 2018 at 6:37 PM, James McMahon <js...@gmail.com>
> wrote:
> > Good afternoon. I am running a python script from an ExecuteScript
> processor
> > in NiFi 0.7.1.c. I'm assuming this is actually running in a Jython
> > environment under the hood of the processor.
> >
> > General question: How can I tell what version of Jython i am employing?
> >
> > Specific problem: I employ an os.statvfs call to check available
> capacity on
> > my disk devices that host my content repo, and that host my data landing
> > zone. In my command line environment - not jython - Python has this
> library
> > and so I can successfully make this call.
> >
> > In NiFi, I get this error at run time:
> >
> > javax.script.ScriptException: AttributeError: 'module' object has no
> > attribute ;statvfs'
> >
> > How can I correct this? I am happy to replace it if necessary with
> something
> > Jython provides, but don't fully understand the Jython environment within
> > NiFi. Is there a suitable Jython equivalent to fix this problem? What
> > package or module must i include in my script to get at that?
> >
> > Thanks in advance for your help.
> >
> > Jim
>
Re: Error in Jython environment
Posted by Joe Witt <jo...@gmail.com>.
Independent of NiFi have you successfully used any version of Jython
to make that call?
With the NiFi 1.x line that processor has been updated a little bit
and in particular i think we have Jython 2.7.1 (off memory so could be
totally nonsense) where as before we had 2.7.0 or something older...
Thanks
On Fri, Apr 13, 2018 at 6:37 PM, James McMahon <js...@gmail.com> wrote:
> Good afternoon. I am running a python script from an ExecuteScript processor
> in NiFi 0.7.1.c. I'm assuming this is actually running in a Jython
> environment under the hood of the processor.
>
> General question: How can I tell what version of Jython i am employing?
>
> Specific problem: I employ an os.statvfs call to check available capacity on
> my disk devices that host my content repo, and that host my data landing
> zone. In my command line environment - not jython - Python has this library
> and so I can successfully make this call.
>
> In NiFi, I get this error at run time:
>
> javax.script.ScriptException: AttributeError: 'module' object has no
> attribute ;statvfs'
>
> How can I correct this? I am happy to replace it if necessary with something
> Jython provides, but don't fully understand the Jython environment within
> NiFi. Is there a suitable Jython equivalent to fix this problem? What
> package or module must i include in my script to get at that?
>
> Thanks in advance for your help.
>
> Jim