[Paraview] pvserver disconnecting...

[pat marion]

Hi,

Your loop is leaking readers.   At the end of your loop, call
Delete(reader).  The Delete() function is analogous to selecting an object
in the paraview gui and pressing the delete key.  You'll still leak some
objects, there are more thorough ways you cleanup, but deleting the reader
make take care of the bulk of it.  You can remove the Initialize() calls.

Pat

On Fri, Feb 11, 2011 at 7:31 AM, Karl Battams <karlbattams at gmail.com> wrote:

> Hi Pat,
>
> Yes -- I should have gone with my first suspicion. It is indeed a memory
> leak. I'm obviously not cleaning stuff up properly... which doesn't surprise
> me because my script really is kind of a hack... I have attached it.
> Basically it reads a directory of vtk files, loops over each, volume-renders
> them with a fixed set of camera positions, and then saves a png.
>
> One issue I was having was getting paraview to "forget" about the previous
> vtk file. It was rendering each new image over the top of the previous one.
> I fixed that by using Initialize( ) on the different views at the end of the
> loop, but that is perhaps (probably!) not the right way to do it.
>
> Many thanks for your help!
>
> Regards,
> Karl
>
> On Thu, Feb 10, 2011 at 3:08 PM, pat marion <pat.marion at kitware.com>wrote:
>
>> Hi Karl,
>>
>> It sounds like a memory leak problem.  Have you tried opening the System
>> Monitor in ubuntu and watching the memory usage of pvserver as you run your
>> script?  Can you post your script so we can take a look at it, maybe you
>> aren't cleaning up after you process each file?
>>
>> You can pass --cslog=log.txt to pvserver.  This records very low level log
>> information, it captures every message sent to the server.  Problem is that
>> it does not work very well for a parallel server, all processes all write to
>> the same file.
>>
>> pvserver exits when the client disconnects and there is no keep-alive
>> flag.  Try running pvserver in a bash loop, or starting it from your python
>> script.
>>
>> Pat
>>
>> On Thu, Feb 10, 2011 at 1:46 PM, Karl Battams <karlbattams at gmail.com>wrote:
>>
>>> I'm pretty new to paraview so could be doing fundamentally wrong here,
>>> but here's my issue...
>>>
>>> I have paraview 3.10 compiled/installed from source on Ubuntu 10. I'm
>>> using a python script to connect to pvserver, iterate over a bunch of vtk
>>> files, do some stuff, and saving the output as a png. I'm running the python
>>> script and the pvserver on the same (8-core) machine.
>>>
>>> So I start pvserver with (e.g.) mpirun -np 6 pvserver and it sits happily
>>> listening for a client. In another terminal, I run my python script which
>>> connects (successfully) to pvserver, and starts running through the files
>>> exactly as I ask it to. So far so good.
>>>
>>> Problem is, after a random length of time, and/or number of files, the
>>> pvserver abruptly dies and so the whole python script obviously dies with
>>> it. The pvserver gives no error message... just dies. If I just run the
>>> script for one file (or even a few of them), it runs without an issue.
>>>
>>> What I have noticed is that the less processors I use, the more files my
>>> script will process before pvserver dies. If I use pvserver by itself (i.e.
>>> one processor) it will do about 120-or-so files. If I use four processors,
>>> it'll only go through 30-or-so before one of them throws a kill signal and
>>> takes the whole thing down. It is not a particular file that does it, nor is
>>> it at a particular point in the processing script. The length of time and
>>> number of files processed is also not fixed. (It's almost like it's a memory
>>> leak issue..??)
>>>
>>> So... questions:
>>> 1) Am I being inefficient/stupid by using pvserver + python script to do
>>> this batch processing? If so, what's the recommended practice?
>>> 2) My script only does one server connect (via Connect('localhost') ) and
>>> then loops over the files. Should I do a new server connect for each file
>>> instead?
>>> 3) Assuming yes to question 2, how do I cleanly disconnect from pvserver
>>> without killing the server altogether (see below)?
>>> 4) If I run a single instance of file processing (i.e. one file) the
>>> script runs fine... but when it's done, the pvserver disconnects the client
>>> and dies. Is that normal? Is there a 'keep-alive' flag for pvserver? Why
>>> does dropping the connection kill the server?
>>> 5) Does pvserver leave any logs anywhere? Anyway I can trace what's
>>> causing the kill signal?
>>>
>>> I just can't shake the feeling that the pvserver process should be a lot
>>> more robust than what I'm seeing.
>>>
>>> Many thanks for any help!
>>> Karl
>>>
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