@mfbalin, @Rhett-Ying When converting partitions of dgl to FusedCSCSamplingGraph of GraphBolt using dgl.distributed.dgl_partition_to_graphbolt, I get the following error when n_jobs > 1. I set n_jobs to 2 which is the number of partitions. Works fine when n_jobs = 1. It appears to be a process spawning error:
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 116, in spawn_main
exitcode = _main(fd, parent_sentinel)
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 125, in _main
prepare(preparation_data)
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 236, in prepare
_fixup_main_from_path(data['init_main_from_path'])
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 287, in _fixup_main_from_path
main_content = runpy.run_path(main_path,
File "/usr/lib/python3.10/runpy.py", line 289, in run_path
return _run_module_code(code, init_globals, run_name,
File "/usr/lib/python3.10/runpy.py", line 96, in _run_module_code
_run_code(code, mod_globals, init_globals,
File "/usr/lib/python3.10/runpy.py", line 86, in _run_code
exec(code, run_globals)
File "convert.py", line 32, in <module>
dgl_partition_to_graphbolt(
File "...lib/python3.10/site-packages/dgl/distributed/partition.py", line 1635, in dgl_partition_to_graphbolt
futures.append(executor.submit(convert_with_format, part_id))
File "/usr/lib/python3.10/concurrent/futures/process.py", line 737, in submit
self._adjust_process_count()
File "/usr/lib/python3.10/concurrent/futures/process.py", line 697, in _adjust_process_count
self._spawn_process()
File "/usr/lib/python3.10/concurrent/futures/process.py", line 714, in _spawn_process
p.start()
File "/usr/lib/python3.10/multiprocessing/process.py", line 121, in start
self._popen = self._Popen(self)
File "/usr/lib/python3.10/multiprocessing/context.py", line 288, in _Popen
return Popen(process_obj)
File "/usr/lib/python3.10/multiprocessing/popen_spawn_posix.py", line 32, in __init__
super().__init__(process_obj)
File "/usr/lib/python3.10/multiprocessing/popen_fork.py", line 19, in __init__
self._launch(process_obj)
File "/usr/lib/python3.10/multiprocessing/popen_spawn_posix.py", line 42, in _launch
prep_data = spawn.get_preparation_data(process_obj._name)
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 154, in get_preparation_data
_check_not_importing_main()
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 134, in _check_not_importing_main
raise RuntimeError('''
RuntimeError:
An attempt has been made to start a new process before the
current process has finished its bootstrapping phase.
This probably means that you are not using fork to start your
child processes and you have forgotten to use the proper idiom
in the main module:
if __name__ == '__main__':
freeze_support()
...
The "freeze_support()" line can be omitted if the program
is not going to be frozen to produce an executable.
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 116, in spawn_main
exitcode = _main(fd, parent_sentinel)
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 125, in _main
prepare(preparation_data)
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 236, in prepare
_fixup_main_from_path(data['init_main_from_path'])
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 287, in _fixup_main_from_path
main_content = runpy.run_path(main_path,
File "/usr/lib/python3.10/runpy.py", line 289, in run_path
return _run_module_code(code, init_globals, run_name,
File "/usr/lib/python3.10/runpy.py", line 96, in _run_module_code
_run_code(code, mod_globals, init_globals,
File "/usr/lib/python3.10/runpy.py", line 86, in _run_code
exec(code, run_globals)
File "convert.py", line 32, in <module>
dgl_partition_to_graphbolt(
File "...lib/python3.10/site-packages/dgl/distributed/partition.py", line 1635, in dgl_partition_to_graphbolt
futures.append(executor.submit(convert_with_format, part_id))
File "/usr/lib/python3.10/concurrent/futures/process.py", line 737, in submit
self._adjust_process_count()
File "/usr/lib/python3.10/concurrent/futures/process.py", line 697, in _adjust_process_count
self._spawn_process()
File "/usr/lib/python3.10/concurrent/futures/process.py", line 714, in _spawn_process
p.start()
File "/usr/lib/python3.10/multiprocessing/process.py", line 121, in start
self._popen = self._Popen(self)
File "/usr/lib/python3.10/multiprocessing/context.py", line 288, in _Popen
return Popen(process_obj)
File "/usr/lib/python3.10/multiprocessing/popen_spawn_posix.py", line 32, in __init__
super().__init__(process_obj)
File "/usr/lib/python3.10/multiprocessing/popen_fork.py", line 19, in __init__
self._launch(process_obj)
File "/usr/lib/python3.10/multiprocessing/popen_spawn_posix.py", line 42, in _launch
prep_data = spawn.get_preparation_data(process_obj._name)
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 154, in get_preparation_data
_check_not_importing_main()
File "/usr/lib/python3.10/multiprocessing/spawn.py", line 134, in _check_not_importing_main
raise RuntimeError('''
RuntimeError:
An attempt has been made to start a new process before the
current process has finished its bootstrapping phase.
This probably means that you are not using fork to start your
child processes and you have forgotten to use the proper idiom
in the main module:
if __name__ == '__main__':
freeze_support()
...
The "freeze_support()" line can be omitted if the program
is not going to be frozen to produce an executable.
Traceback (most recent call last):
File "convert.py", line 32, in <module>
dgl_partition_to_graphbolt(
File "...lib/python3.10/site-packages/dgl/distributed/partition.py", line 1638, in dgl_partition_to_graphbolt
rel_path_results.append(futures[part_id].result())
File "/usr/lib/python3.10/concurrent/futures/_base.py", line 451, in result
return self.__get_result()
File "/usr/lib/python3.10/concurrent/futures/_base.py", line 403, in __get_result
raise self._exception
concurrent.futures.process.BrokenProcessPool: A process in the process pool was terminated abruptly while the future was running or pending.
Also, in the source code, the signature is this:
def dgl_partition_to_graphbolt(
part_config,
*,
store_eids=True,
store_inner_node=False,
store_inner_edge=False,
graph_formats=None,
n_jobs=1,
):
But in the latest documentation, the signature is this:
dgl.distributed.dgl_partition_to_graphbolt(
part_config,
*,
store_eids=False,
store_inner_node=False,
store_inner_edge=False
)
There is no graph_formats and n_jobs params in the documentation. Are these not supposed to be used?