Array parameters retrieval fail when the size is very big

[germa89]

As the title.

It will take extensive debugging in MAPDL.

Example

import numpy as np
from ansys.mapdl.core import launch_mapdl

mapdl = launch_mapdl()

mapdl.finish()
mapdl.clear()

mapdl.prep7()
dimensions = 1E7

mapdl.dim("myarr","", dimensions)
mapdl.vfill("myarr","rand",0, 1)  # filling array with random numbers

# Retrieving
values = mapdl.parameters["myarr"]  # fail with "MapdlExitedError: MAPDL server connection terminated"

# Setting
myarr = np.random.rand(int(1E7))
mapdl.parameters["myarr2"] = myarr*2

[germa89]

Hi German,
So it looks like the issue is calling *VREAD in a loop; at some point MAPDL crashes (still not sure if it is PyMAPDL or MAPDL). For this case I got rid of all the loops to set parameters and used the good old method of defining a huge table as a CSV and read it all at once using *TREAD. Luckily it works!

What does mapdl.parameters["SET_PARAM"] = ... use behind the scenes? I am assuming it does exactly what I tried using *VREAD; that is why I see the exact same behaviour / crash?

By @ayush-kumar-423 Related to #2844

[germa89]

More info on this:

<_InactiveRpcError of RPC that terminated with:
        status = StatusCode.RESOURCE_EXHAUSTED
        details = "Received message larger than max (450037158 vs. 268435456)"
        debug_error_string = "UNKNOWN:Error received from peer ipv4:10.105.52.33:50052 {created_time:"2024-07-30T11:52:58.266896+02:00", grpc_status:8, grpc_message:"Received message larger than max (450037158 vs. 268435456)"}"

Details:

Retrieving...
Traceback (most recent call last):
  File "/Users/german.ayuso/pymapdl/src/ansys/mapdl/core/parameters.py", line 371, in __getitem__
    val_ = interp_star_status(self._mapdl.starstatus(key))
  File "/Users/german.ayuso/pymapdl/src/ansys/mapdl/core/_commands/session/run_controls.py", line 590, in starstatus
    return self.run(command, **kwargs)
  File "/Users/german.ayuso/pymapdl/src/ansys/mapdl/core/mapdl_core.py", line 2212, in run
    text = self._run(command, verbose=verbose, mute=mute)
  File "/Users/german.ayuso/pymapdl/src/ansys/mapdl/core/mapdl_grpc.py", line 904, in _run
    response = self._send_command(cmd, mute=mute)
  File "/Users/german.ayuso/pymapdl/src/ansys/mapdl/core/errors.py", line 330, in wrapper
    raise MapdlExitedError(
ansys.mapdl.core.errors.MapdlExitedError: MAPDL server connection terminated unexpectedly while running:
*STATUS,MYARR,,,,,,,,,,,
called by:
_send_command
with the following error
<_InactiveRpcError of RPC that terminated with:
        status = StatusCode.RESOURCE_EXHAUSTED
        details = "Received message larger than max (450037158 vs. 268435456)"
        debug_error_string = "UNKNOWN:Error received from peer ipv4:10.105.52.33:50052 {created_time:"2024-07-30T11:52:58.266896+02:00", grpc_status:8, grpc_message:"Received message larger than max (450037158 vs. 268435456)"}"
>

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/german.ayuso/pymapdl/tmp/tmp3.py", line 26, in <module>
    values = mapdl.parameters["myarr"]  # fail with "MapdlExitedError: MAPDL server connection terminated"
  File "/Users/german.ayuso/pymapdl/src/ansys/mapdl/core/parameters.py", line 379, in __getitem__
    raise IndexError("%s not a valid parameter_name" % key)
IndexError: MYARR not a valid parameter_name

Code to replicate

Details

import numpy as np
from ansys.mapdl.core import launch_mapdl

mapdl = launch_mapdl()

mapdl.finish()
mapdl.clear()

mapdl.prep7()

for dimensions in np.logspace(1, 7, 7):
    print(dimensions)
    dimensions = int(dimensions)

    mapdl.dim("myarr","", dimensions)
    mapdl.vfill("myarr","rand",0, 1)  # filling array with random numbers

    # Retrieving
    print("Retrieving...")
    values = mapdl.parameters["myarr"]  # fail with "MapdlExitedError: MAPDL server connection terminated"
    print("Retrieved.")

    # Setting
    myarr = np.random.rand(dimensions)
    print("Setting...")
    mapdl.parameters["myarr2"] = myarr*2
    print("Set")

[germa89]

This can be overcomed by changing the env var PYMAPDL_MAX_MESSAGE_LENGTH:

export PYMAPDL_MAX_MESSAGE_LENGTH=471859200

It set to -1 it should remove any lenght limit.

Ideally we would like a more explicit message when failing.