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Unexpected MAPDL server disconnection while running a series of ``aplot()``
Discussed in https://github.com/pyansys/pymapdl/discussions/1411
Originally posted by hawkoli1987 August 26, 2022 Dear All,
I am trying to generating a random range of 2D shapes in series, there are 100 numbers of such shapes in total. For each shape generated, I ordered a printout of it via mapdl.aplot(). After a bunch of such shapes were successfully generated, there is always an automatic server disconnection which stops me from generating new shapes.
However, if I simply change the aplot() to lplot(), it will complete the generation process successfully.
Another issue I had was that on one side of the shape, it's a curve that was generated by fitting a spline through a series of keypoints. Among all the area plots, I can always spot a few that looks like straight line-segments rather than a spline.
I would assume both issues are connected? and perhaps both was caused by insufficient memory? I attached my code here in a zip. Please enlighten me on this, thanks!
---------------------------------------------------------------------------
MapdlExitedError Traceback (most recent call last)
Input In [5], in <cell line: 124>()
125 geo = Geometry(curve = line.tolist())
126 mat = Material()
--> 127 get_Ue(mat, geo)
Input In [5], in get_Ue(mat, geo, c_r, force, disp, AESIZE, refine_lvl, detach_step)
114 else:
115 mapdl.rectng(0, geo.diameter/2, 0, geo.height)
--> 116 mapdl.aplot('ALL',cpos="xy")
117 return
File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\mapdl.py:1478, in _MapdlCore.aplot(self, na1, na2, ninc, degen, scale, vtk, quality, show_area_numbering, show_line_numbering, color_areas, show_lines, **kwargs)
1476 if quality < 1:
1477 quality = 1
-> 1478 surf = self.geometry.generate_surface(11 - quality, na1, na2, ninc)
1479 meshes = []
1480 labels = []
File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\misc.py:324, in supress_logging.<locals>.wrapper(*args, **kwargs)
321 if prior_log_level != "CRITICAL":
322 mapdl._set_log_level("CRITICAL")
--> 324 out = func(*args, **kwargs)
326 if prior_log_level != "CRITICAL":
327 mapdl._set_log_level(prior_log_level)
File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\misc.py:346, in run_as_prep7.<locals>.wrapper(*args, **kwargs)
343 if prior_processor != "PREP7":
344 mapdl.prep7()
--> 346 out = func(*args, **kwargs)
348 if prior_processor == "Begin level":
349 mapdl.finish()
File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\mapdl_geometry.py:293, in Geometry.generate_surface(self, density, amin, amax, ninc)
290 self._mapdl.prep7(mute=True)
292 # Mesh and get the number of elements per area
--> 293 resp = self._mapdl.amesh("all")
294 groups = get_elements_per_area(resp)
296 self._mapdl.esla("S")
File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\_commands\preproc\meshing.py:182, in Meshing.amesh(self, na1, na2, ninc, **kwargs)
160 """Generates nodes and area elements within areas.
161
162 APDL Command: AMESH
(...)
179 This command is also valid for rezoning.
180 """
181 command = f"AMESH,{na1},{na2},{ninc}"
--> 182 return self.run(command, **kwargs)
File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\mapdl.py:2630, in _MapdlCore.run(self, command, write_to_log, mute, **kwargs)
2627 self._check_parameter_name(param_name)
2629 verbose = kwargs.get("verbose", False)
-> 2630 text = self._run(command, verbose=verbose, mute=mute)
2632 if mute:
2633 return
File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\mapdl_grpc.py:736, in MapdlGrpc._run(self, cmd, verbose, mute)
734 response = self._send_command_stream(cmd, True)
735 else:
--> 736 response = self._send_command(cmd, mute=mute)
737 self._busy = False
739 return response.strip()
File ~\anaconda3\envs\pyansys_env\lib\site-packages\ansys\mapdl\core\errors.py:138, in protect_grpc.<locals>.wrapper(*args, **kwargs)
136 # Must close unfinished processes
137 mapdl._close_process()
--> 138 raise MapdlExitedError("MAPDL server connection terminated") from None
140 if threading.current_thread().__class__.__name__ == "_MainThread":
141 received_interrupt = bool(SIGINT_TRACKER)
MapdlExitedError: MAPDL server connection terminated
---------------------------------------------------------------------------
File:
Issue.zip hawkoli1987
Interesting...
After a while it doesn't seem to do the splines properly:
However, the MAPDL figure does show correct geometry:
Hence I believe the interpolation thing it is more an mapdl-pyvista mapping issue. I will open another issue about this.
I'm using a slightly modified version of OP's code:
Show me
#!/usr/bin/env python
# coding: utf-8
# In[5]:
import numpy as np
from numpy.lib.stride_tricks import sliding_window_view
import matplotlib.pyplot as plt
import math
import random
import matplotlib.pyplot as plt
# from scipy.integrate import quad
from math import* #import all function from math
from ansys.mapdl.core import launch_mapdl
exec_loc = 'C:/Program Files/ANSYS Inc/v222/ANSYS/bin/winx64/ANSYS222.exe'
mapdl = launch_mapdl(exec_loc, port=50060, add_env_vars={'ANS_DEBUG_CRASH':1})
print(mapdl)
print(mapdl.directory)
mapdl.nerr(200, 99999999, -1)
def Coefficient_Gen(pop_size, mode = 20, center_tolerance=1, max_amplitude=8):
n = mode
tol = center_tolerance
Ans = np.empty(shape = (0,20))
Bns = np.empty(shape = (0,20))
while Ans[:,0].size < pop_size:
An = np.expand_dims(np.array([random.uniform(-1, 1) for _ in range(n)]), axis = 0)
Bn = np.expand_dims(np.array([random.uniform(-1, 1) for _ in range(n)]), axis = 0)
line = to_Fourier(An, Bn)
line_max = np.absolute(line).max()
line_avg = np.average(line)
if line_avg<-tol or line_avg>tol or line_max>max_amplitude:
continue
Ans = np.vstack((Ans, An))
Bns = np.vstack((Bns, Bn))
DNAs = np.hstack((Ans, Bns))
return DNAs
def to_Fourier(An, Bn, segment = 20):
if An.shape == Bn.shape:
n = An[0,:].size
else:
print('Error: coefficients size mismatch')
x=np.arange(-np.pi,np.pi,2*np.pi/segment) #x axis has been chosen from –π to +π, value
x=np.expand_dims(x, 0)
total = 0
for i in range(n):
if i==0.0:
total+=An[:,i]/2 # in case n=0
total=total[:,np.newaxis]
else:
total = total + An[:,i][:,np.newaxis]*np.cos(i*x)+Bn[:,i][:,np.newaxis]*np.sin(i*x)
return total
POP_SIZE = 100
DNA_SIZE = 40
class Material:
"""
elastic modulus (kPa),
poisson ratio
work of adhesion (mJ/m^2)
"""
def __init__(self, E_modulus = 500, nu=0.4, w_ad = 20):
self.E_modulus = E_modulus*1e-3 # elasticu modulus: kPa -> uN/um^2
self.nu = nu # poisson ratio: dimensionless
self.w_ad = w_ad *1e-3 # work of adhesion: mJ/m^2 -> uN/um
class Geometry:
"""
unit (um)
"""
def __init__(self, height = 100, diameter=50, curve=[]):
self.height = height # fiber height: um
self.diameter = diameter # fiber average diameter: um
self.curve = curve # curved side profile, either None (straight edge) or 1D array of radius
def translateDNA(pop): # DNA samples to split into different gene groups, e.g. An, Bn
An = pop[:,:int(DNA_SIZE/2)]
Bn = pop[:,int(DNA_SIZE/2):]
return An, Bn
def get_Ue(mat, geo, c_r=None, force=None, disp=None, AESIZE=5, refine_lvl=3, detach_step=5):
# reset mapdl
mapdl.clear()
mapdl.prep7()
# Define element attributes
# keyoption 3 = 1 (axis-symmetric formulation)
mapdl.et(1, "PLANE182", kop3=1)
# create cross-sectional area of fiber
if geo.curve != []:
line = geo.curve
n = len(line)
segment = geo.height/(n-1)
for i, value in enumerate(line):
mapdl.k(i+2, value+geo.diameter/2, i*segment)
mapdl.ksel('all')
mapdl.run("BSPLIN, 'all'")
mapdl.cm("curved_edge", "LINE")
mapdl.k(1,0,0) # starting at origin
mapdl.k(n+2,0,geo.height) # ending at the top
mapdl.lstr(1,2)
mapdl.lstr(n+1,n+2)
mapdl.lstr(n+2,1)
try:
mapdl.al('ALL')
except:
mapdl.lplot('ALL',cpos="xy")
else:
mapdl.rectng(0, geo.diameter/2, 0, geo.height)
mapdl.aplot('ALL',cpos="xy")
mapdl.aplot(vtk=False)
return
pop = Coefficient_Gen(pop_size = POP_SIZE) # initialize the pop DNA
An, Bn = translateDNA(pop)
lines = to_Fourier(An, Bn)
print(lines)
for ind, line in enumerate(lines):
print(f"Line: {ind}/{len(lines)}")
geo = Geometry(curve = line.tolist())
mat = Material()
get_Ue(mat, geo)
I get the same error as OP:
---------------------------------------------------------------------------
MapdlExitedError Traceback (most recent call last)
c:\ansys_jobs\aplot_failing\Issue.py in <module>
138 geo = Geometry(curve = line.tolist())
139 mat = Material()
--> 140 get_Ue(mat, geo)
141
142
c:\ansys_jobs\aplot_failing\Issue.py in get_Ue(mat, geo, c_r, force, disp, AESIZE, refine_lvl, detach_step)
124 mapdl.aplot(vtk=False)
125 except:
--> 126 mapdl.lplot('ALL',cpos="xy")
127 else:
128 mapdl.rectng(0, geo.diameter/2, 0, geo.height)
~\Others_pymapdls\pymapdl_1\pymapdl\src\ansys\mapdl\core\mapdl.py in lplot(self, nl1, nl2, ninc, vtk, show_line_numbering, show_keypoint_numbering, color_lines, **kwargs)
1726 kwargs.setdefault("show_scalar_bar", False)
1727 kwargs.setdefault("title", "MAPDL Line Plot")
-> 1728 if not self.geometry.n_line:
1729 warnings.warn(
1730 "Either no lines have been selected or there is nothing to plot."
~\Others_pymapdls\pymapdl_1\pymapdl\src\ansys\mapdl\core\mapdl_geometry.py in n_line(self)
363 1
364 """
--> 365 return self._item_count("LINE")
366
367 @property
~\Others_pymapdls\pymapdl_1\pymapdl\src\ansys\mapdl\core\misc.py in wrapper(*args, **kwargs)
373 mapdl._set_log_level("CRITICAL")
374
--> 375 out = func(*args, **kwargs)
376
377 if prior_log_level != "CRITICAL":
~\Others_pymapdls\pymapdl_1\pymapdl\src\ansys\mapdl\core\mapdl_geometry.py in _item_count(self, entity)
380 def _item_count(self, entity):
381 """Return item count for a given entity."""
--> 382 return int(self._mapdl.get(entity=entity, item1="COUNT"))
383
384 @property
~\Others_pymapdls\pymapdl_1\pymapdl\src\ansys\mapdl\core\mapdl.py in get(self, par, entity, entnum, item1, it1num, item2, it2num, item3, **kwargs)
2240 # Checking printout is not suppressed by checking "wrinqr" flag.
2241 flag = 0
-> 2242 if self.wrinqr(1) != 1: # using wrinqr is more reliable than *get
2243 flag = 1
2244 self._run("/gopr")
~\Others_pymapdls\pymapdl_1\pymapdl\src\ansys\mapdl\core\mapdl_grpc.py in wrinqr(self, key, **kwargs)
2513 def wrinqr(self, key, **kwargs):
2514 """Wrap the ``wrinqr`` method to take advantage of the gRPC methods."""
-> 2515 super().wrinqr(key, pname=TMP_VAR, mute=True, **kwargs)
2516 return self.scalar_param(TMP_VAR)
2517
~\Others_pymapdls\pymapdl_1\pymapdl\src\ansys\mapdl\core\_commands\inq_func.py in wrinqr(self, key, pname, **kwargs)
1404
1405 """
-> 1406 return self.run(f"{pname} = wrinqr({key})", **kwargs)
~\Others_pymapdls\pymapdl_1\pymapdl\src\ansys\mapdl\core\mapdl.py in run(self, command, write_to_log, mute, **kwargs)
2694
2695 verbose = kwargs.get("verbose", False)
-> 2696 text = self._run(command, verbose=verbose, mute=mute)
2697
2698 if mute:
~\Others_pymapdls\pymapdl_1\pymapdl\src\ansys\mapdl\core\mapdl_grpc.py in _run(self, cmd, verbose, mute)
744 response = self._send_command_stream(cmd, True)
745 else:
--> 746 response = self._send_command(cmd, mute=mute)
747 self._busy = False
748
~\Others_pymapdls\pymapdl_1\pymapdl\src\ansys\mapdl\core\errors.py in wrapper(*args, **kwargs)
143 # Must close unfinished processes
144 mapdl._close_process()
--> 145 raise MapdlExitedError("MAPDL server connection terminated") from None
146
147 if threading.current_thread().__class__.__name__ == "_MainThread":
MapdlExitedError: MAPDL server connection terminated
And there is no generated ANS_DEBUG_CRASH file.
The fundamental issue is we're not transferring the underlying tessellated geometry from MAPDL to Python, but rather we have to generate a faux FEA mesh overlaid on top of the existing areas. This has always been a stopgap, waiting for an API to directly transfer the tessellated faces generated with the underlying APLOT command.
Whether or not we do this depends on how long we plan on using the internal MAPDL geometry kernel. Since we have nothing to replace it with, I think we should still support it.
Whether or not we do this depends on how long we plan on using the internal MAPDL geometry kernel. Since we have nothing to replace it with, I think we should still support it.
I agree on this.
I cannot understand though how the crash is happening in the current implementation. The geometry kernel should be stable enough to support create, export and delete a faux FEA mesh.
I will propose then to leave this on hold until more progress is made on the gRPC implementation.
I recheck this issue on the latest PyMAPDL version and 222, I still get the same MAPDL crash.