CFD POST segmentation violation

[Daniel.dejan.gunde]

Hi,

I get frequently this error when switching to different time step in the Timestep Selector. I'm working with cas and cdat files by Fluent. This makes impossible to do data analysis.

Thank you for your help!

Best wishes,

Daniel

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 signal 11 was caught: segmentation violation
Socket error: recv: connection reset
Aborting due to unexpected error:
socketError: RemoteEngineProtocol::receiveTransStat - Communications error: unexpected end of transmission from engine, expected status code.
The application has encountered an unexpected problem and will now terminate:

Aborting due to unexpected error:
socketError: RemoteEngineProtocol::receiveTransStat - Communications error: unexpected end of transmission from engine, expected status code.

Please report this error, along with the circumstances in which it occurred.

The following information may be useful to CFX support:

Unexpected error: Aborting due to unexpected error:
socketError: RemoteEngineProtocol::receiveTransStat - Communications error: unexpected end of transmission from engine, expected status code.

Socket error: recv: connection reset
----------------------------------------------------------------------

[NickFL]

What are you trying to post-process in Post that you cannot do directly in Fluent? There are only a couple of things that should be done in Post that cannot be done in Fluent, such as Volume Rendering. And even that is now, if I am not mistaken, in the Beta phase for Fluent. And if you are using Workbench, I would just suggest to run in stand-alone mode for each of the software. There are too many moving parts when doing complex studies/research to have Workbench work flawlessly.

[Daniel.dejan.gunde]

Just simple animations in stand-alone Post, pressure and velocity fields on a plane. But I do have a lot of cdat files, tens of thousands.

[NickFL]

 

Then I will ask again, why are you not doing this in Fluent directly? The data is already open and stored in memory. You can save your images as a fixed position based upon predefined contours/planes or even with the HSF a 3D “image” that you can adjust and rotate. By bringing CFD Post into the picture you are just filling up your hard-drive space and increasing someone’s electric bill.

You should be able to create some scripts in Post that open and read in the data. This code would be in Perl, but for this it should not be difficult. That will allow you to identify file(s) or timesteps that are corrupt. You can then skip over these when doing your video animation creation. It will have a small "skip" but given the number of time steps you seem to have, I doubt it would be noticeable.  

 

 

[Vivek Praveen]

Hi

As you mentioned 'I get frequently', does it happen with less number of cdat, or this happens generally independant of number of files?

[Daniel.dejan.gunde]

I suspected that so I divided the results into folders with much lower number of result files and it didn't help. It interstingly got stuck everytime at the same or similar time stamp so I rerun that part of simulation with no success. I suspected that maybe just 1 file is currupted so I was searching it among about 70.000 files and when I thought I found it and excluded it from the animation suddenly got the same error anyway.

[Rob]

Are you reading one case and many cdat or pairs of files? Did you load the data by opening the flpj file? 

[Daniel.dejan.gunde]

I have pairs of cas and cdat files as the mesh changes every time step. I tried loading the data with the flpj file and it didn't open all the transient files. I'm opening the case with the last cdat file I'm interested in. In most cases it works normally. Now it happened the second time that it didn't work and I get the same or similar error.

[Rob]

70k files does seem a little excessive. What is changing in the mesh? I also assume you've not accidentially overwritten one case or cdat? 

[Daniel.dejan.gunde]

I misstankenly exagarated a little. In this problematic case I have about 14.000 pairs of cas and cdat files. I'm applying the layering method of dynamic mesh and I need quite small time step size. At my latest try I just wanted to switch from the last time step to a certain time step back in time (at 110s of simulation time to 75s) and got this a bit different error:

[48476:44928:0604/155728.072:ERROR:dns_config_service_win.cc(785)] DNS config watch failed.
 signal 11 was caught: segmentation violation
Aborting due to unexpected error:
comm::error: RemoteEngineProtocol::sendInternal - A fatal error has occurred during communication with the engine:
socketError: Socket::socketSend - send: connection reset
Socket error: recv: connection reset
The application has encountered an unexpected problem and will now terminate:

Aborting due to unexpected error:
comm::error: RemoteEngineProtocol::sendInternal - A fatal error has occurred during communication with the engine:
socketError: Socket::socketSend - send: connection reset

Please report this error, along with the circumstances in which it occurred.

The following information may be useful to CFX support:

Unexpected error: Aborting due to unexpected error:
comm::error: RemoteEngineProtocol::sendInternal - A fatal error has occurred during communication with the engine:
socketError: Socket::socketSend - send: connection reset

[NickFL]

Where is this error occurring? Are you using Workbench? Workbench works great for flow in a pipe, anything more complex move over to stand-alone. That might be a slight exaggeration, but transient problems in Workbench sounds like trouble. 

[Daniel.dejan.gunde]

I'm using stand alone Post. I'm not doing this directly in Fluent because there are too many issues with that approach. Both with generating the data and postprocessing. I won't go into those details.

I could finaly generate an animation now but I needed to start from scratch. I had a state file with some expressions, ready planes, lines, plots, and so on. It was convenient to use the same state file for different runs. It might be somehow related to the moving mesh. When I was working with stationary meshes I never had those issues.

I noticed that Post hasn't been updated for a while. Are you focusing now on other ways to postprocess CFD data? I know you work on Discovery but it will take a while when Discovery will be able to run more advanced simulations.

[Rob]

Chances are something ran out of allocation (14,000 pairs is still somewhat high) or a surface disappeared that's needed for "something". Remember most people won't notice resolution higher than about 25 fps in a simulation movie. 

The main focus at present is to move the various functions from Ensight and CFD Post into Fluent. I can't really comment further on plans as I'm staff and not entirely sure what's public.