Dask on JupyterHub

We have a prepared conda environment to use with dask

To properly use dask from the jupyterhub conda environment use the following settings

import dask
import dask.distributed  
 
import os
 
DASHBOARD_PORT = 41231      # a port of your choosing - should be free on the node running the notebook
 
user = os.environ.get('USER')
 
dask.config.set({'distributed.dashboard.link': f'/user/{user}/proxy/{DASHBOARD_PORT}/status'})
dask.config.get('distributed.dashboard.link')
 
from dask_jobqueue import SLURMCluster
 
cluster = SLURMCluster(queue='mem_0096',       # specify the **partition** to use (even though it says queue)
                       project='sysadmin',     # use your project e.g. p72310
                       cores=48,               # how many cores should each worker job have
                       memory='10GB',          # how much memory should every worker job have
                       processes=1             # each worker starts multiple processes (using the resources) - depends on your problem
                       walltime='00:05:00',    # maximum runtime of a worker job
                       interface='ib0',        # interface for workers to communicate on
                       scheduler_options={'interface': 'eno1',                         # scheduler interface
                                          'dashboard_address': f':{DASHBOARD_PORT}'},  # set a different dashboard port to avoid collisions
                       job_extra=['--qos="admin"', '-N 1'],                            # manually set a qos and optional additional node specs
                       header_skip=['-n 1'])                                           # omit this line from the generated job script (needed so we can add our own above)
print(cluster.job_script())
 
cluster.scale(jobs=1)    # jobs here means how many slurm worker jobs we will get
 
cluster.get_logs()       # check if the jobs have been allocated and the workers are connected - alternatively check via slurm squeue -u <USERNAME> 
 
from dask.distributed import Client
client = Client(cluster)     # create a client using the cluster
 
# now schedule some work
 
import dask.array as da
 
x = da.random.random((10_000,10_000,10), chunks=(1000,1000,5))
y = da.random.random((10_000,10_000,10), chunks=(1000,1000,5))
z = (da.arcsin(x) + da.arccos(y)).sum(axis=(1,))
 
z.compute()
 
cluster.close()           # stop the cluster once you're done (also happens automatically when the notebook kernel exits)