Set interface in SLURMRunner

[jacobtomlinson]

Hello from a new user! I'm putting this here rather than opening a new issue, but let me know if I should do the latter instead.

Following the documentation, I am trying to run my very first "hello dask" script that looks like the following:

from dask.distributed import Client
from dask_jobqueue.slurm import SLURMRunner

with SLURMRunner() as runner:
    with Client(runner) as client:
        client.wait_for_workers(runner.n_workers)
        print(f"Number of workers = {runner.n_workers}")

When I submit the job using slurm, I get the following network-related warning

2025-02-12 16:22:11,565 - distributed.scheduler - INFO - State start
/home/sm69/.conda/envs/pyathena/lib/python3.13/site-packages/distributed/utils.py:189: RuntimeWarning: Couldn't detect a suitable IP address for reaching '8.8.8.8', defaulting to hostname: [Errno 101] Network is unreachable
  warnings.warn(
2025-02-12 16:22:11,569 - distributed.scheduler - INFO -   Scheduler at:  tcp://10.33.81.152:35737
2025-02-12 16:22:11,569 - distributed.scheduler - INFO -   dashboard at:  http://10.33.81.152:8787/status
2025-02-12 16:22:11,569 - distributed.scheduler - INFO - Registering Worker plugin shuffle
2025-02-12 16:22:11,647 - distributed.scheduler - INFO - Receive client connection: Client-6c2bbb5b-e987-11ef-b579-78ac4413ab38
2025-02-12 16:22:11,647 - distributed.core - INFO - Starting established connection to tcp://10.33.81.152:58686
2025-02-12 16:22:11,658 - distributed.worker - INFO -       Start worker at:   tcp://10.33.81.152:42115
2025-02-12 16:22:11,658 - distributed.worker - INFO -          Listening to:   tcp://10.33.81.152:42115
2025-02-12 16:22:11,658 - distributed.worker - INFO -       Start worker at:   tcp://10.33.81.152:38967
2025-02-12 16:22:11,658 - distributed.worker - INFO -       Start worker at:   tcp://10.33.81.152:44313
2025-02-12 16:22:11,658 - distributed.worker - INFO -       Start worker at:   tcp://10.33.81.152:42309
2025-02-12 16:22:11,658 - distributed.worker - INFO -           Worker name:                          9
2025-02-12 16:22:11,659 - distributed.worker - INFO -          dashboard at:         10.33.81.152:46699
2025-02-12 16:22:11,659 - distributed.worker - INFO - Waiting to connect to:   tcp://10.33.81.152:35737
2025-02-12 16:22:11,659 - distributed.worker - INFO -       Start worker at:   tcp://10.33.81.152:34517
...

Followed by StreamClosedError and CommClosedError

Before get into the Runner, I have already tried using Cluster, by, e.g.,

ncores = 96
SLURMCluster(cores=ncores, memory='720 GiB', processes=ncores, interface="ib0")

As you can see here, I had to set interface="ib0" (the cluster uses infiniband for inter-node communication); otherwise I got similar error.

This made me think that I have to do something similar to interface="ib0" when using SLURMRunner as well, but I couldn't find such thing in the documentation. Could you guide me what to do?

Somewhat related feedback from a new user's perspective: It was a surprise to me when I first realize SLURMCluster does not support multi-node job. I was not mentioned explicitly in the documentation, and I had to surf through several issues to come to realize that is the case. I think one of the main motivation to use dask is to overcome single node memory bound when analyzing large simulation data, so I naively assumed that dask-jobqueue would support multi-node job. It might be very helpful that documentation explicitly says that SLURMCluster cannot submit multi-node job.

Originally posted by @sanghyukmoon in #638

[jacobtomlinson]

You should be able to configure the interface today like this

from dask.distributed import Client
from dask_jobqueue.slurm import SLURMRunner

with SLURMRunner(scheduler_options={"interface": "ib0"}, worker_options={"interface": "ib0"}) as runner:
    with Client(runner) as client:
        client.wait_for_workers(runner.n_workers)
        print(f"Number of workers = {runner.n_workers}")

I agree it might be nice to set a top-level interface= keyword that we pass along to both options under the hood. We do this already for scheduler_file=.

dask-jobqueue/dask_jobqueue/slurm.py

Line 206 in e67631d

def __init__(self, *args, scheduler_file="scheduler-{job_id}.json", **kwargs):

dask-jobqueue/dask_jobqueue/slurm.py

Lines 228 to 235 in e67631d

	if isinstance(kwargs.get("scheduler_options"), dict):
	kwargs["scheduler_options"]["scheduler_file"] = scheduler_file
	else:
	kwargs["scheduler_options"] = {"scheduler_file": scheduler_file}
	if isinstance(kwargs.get("worker_options"), dict):
	kwargs["worker_options"]["scheduler_file"] = scheduler_file
	else:
	kwargs["worker_options"] = {"scheduler_file": scheduler_file}

[jacobtomlinson]

One way we could implement this would be to capture **kwargs in the BaseRunner.__init__() and update those into the scheduler_options and worker_options.

dask-jobqueue/dask_jobqueue/runner.py

Lines 61 to 70 in e67631d

	def __init__(
	self,
	scheduler: bool = True,
	scheduler_options: Dict = None,
	worker_class: str = None,
	worker_options: Dict = None,
	client: bool = True,
	asynchronous: bool = False,
	loop: asyncio.BaseEventLoop = None,
	):

That way you could pass abritrary kwargs to SLURMRunner as long as they both exist in the Scheduler and Worker classes and they would get passed all the way down.

[sanghyukmoon]

You should be able to configure the interface today like this

from dask.distributed import Client
from dask_jobqueue.slurm import SLURMRunner

with SLURMRunner(scheduler_options={"interface": "ib0"}, worker_options={"interface": "ib0"}) as runner:
    with Client(runner) as client:
        client.wait_for_workers(runner.n_workers)
        print(f"Number of workers = {runner.n_workers}")

This indeed worked, thanks!

Is there a use case where scheduler and worker processes rely on different network interfaces? Because otherwise, one may simply have a single interface= type argument as you suggested.

[jacobtomlinson]

Sometimes you might want the client <> scheduler communication to be on a different interface then worker <> scheduler communication. Being able to set scheduler_options and worker_options gives a lot of flexibility when configuring clusters.

However I think 99% of the time if you are setting the interface to ib0 you want to do it everywhere. So making a single interface= kwarg too would make this more pleasant for most users.