AttributeError: 'MacSafeQueue' object has no attribute '_counter' when using MonitoringHub on MacOS with HTEX #3856
Description
Describe the bug
Parsl experiences a exception when attempting to run MonitoringHub on MacOS: AttributeError: 'MacSafeQueue' object has no attribute '_counter'. This results in a hung process which never seems to exit and has to be manually terminated. The monitoring.db` database seems to be created but not populated afterwards. I tested this quickly within a Ubuntu 22.04.4 environment and the same does not occur (runs successfully and populates the monitoring database).
To Reproduce
- MacOS 15
- Python 3.10
- Parsl 2025.5.12
- Install deps:
pip install "parsl[monitoring] numpy - Run the following code using
python test.py
import parsl
from parsl.config import Config
from parsl.executors import HighThroughputExecutor
from parsl.monitoring.monitoring import MonitoringHub
from parsl.addresses import address_by_route
from parsl.app.app import python_app
if __name__ == '__main__':
# Load a Parsl configuration with the HTEX executor
parsl.load(Config(
executors=[
HighThroughputExecutor(
label="local_htex",
cores_per_worker=1,
max_workers_per_node=4,
address=address_by_route(),
)
],
monitoring=MonitoringHub(
hub_address=address_by_route(),
monitoring_debug=True,
resource_monitoring_interval=0.0001,
),
strategy='none'
))
@python_app
def allocate_memory(task_id):
import numpy as np
arr = np.ones((40_000_000,), dtype=np.float64)
return f"Task {task_id} allocated memory successfully"
# Launch 3 memory-using tasks
futures = [allocate_memory(0)]
# Collect and print results
for fut in futures:
print(fut.result())
parsl.dfk().cleanup()Expected behavior
I'd hope that the process is able to complete successfully or provide helpful information on how to troubleshoot or diagnose the challenge.
Distributed Environment
- Parsl was launched on a local MacOS machine for testing.