Using Dask in Lotus from the JASMIN Notebooks Service.

Using dask in Lotus requires connecting to a proxy service, called dask-gateway, which will create Lotus jobs on your behalf and proxy communication between your dask client and the dask clusters running in Lotus.

Before using dask gateway on JASMIN, you first need to apply for the "dask" service on the JASMIN accounts portal, which you can do so here: https://accounts.jasmin.ac.uk/services/additional_services/dask/

Creating a dask cluster.

To create and connect to a dask cluster, you can use the following python snippet. Note that this will only work on the JASMIN Notebook service.

import dask_gateway

# Create a connection to dask-gateway.
gw = dask_gateway.Gateway("https://dask-gateway.jasmin.ac.uk", auth="jupyterhub")

# Inspect and change the options if required before creating your cluster.
options = gw.cluster_options()
options.worker_cores = 2

# Create a dask cluster, or, if one already exists, connect to it.
# This stage creates the scheduler job in SLURM, so may take some time.
# While your job queues.
clusters = gw.list_clusters()
if not clusters:
    cluster = gw.new_cluster(options, shutdown_on_close=False)
else:
    cluster = gw.connect(clusters[0].name)

# Create at least one worker, and allow your cluster to scale to three.
cluster.adapt(minimum=1, maximum=3)

# Get a dask client.
client = cluster.get_client()

When you are done, and whish to release your cluster:

cluster.shutdown()

Other information and FAQs.

Accessing the dask dashboard.

Currently the dask dashboard is not accessible from a browser outside the JASMIN firewall. If you're browser fails to load the dashboard link returned, please use our interactive login service to run a browser inside the firewall to view your dashboard.