Some useful information on using Jupyter Lab on UBELIX compute nodes.
IMPORTANT: in the following we show how to start the server on a compute node. Please keep in mind that these resources will be dedicated for you, thus and idle session will waste resources. Please quit your session as soon as you don’t use it anymore, even for a lunch break. Your notebook will maintain all you input/output.
On UBELIX we provide Jupyter Lab for working with Jupyter Notebooks. JupyterLab is a single-user web-based Notebook server, running in the user space. JupyterLab servers should be started preferably on a compute node, especially for compute intensive or memory intensive workloads. After starting the Jupyter Lab server your local browser can be connected using port forwarding. Therefore port forwarding needs to be enabled properly. On this page we describe:
- Launch JupyterLab
- Connect to UBELIX and establishing SSH port forwarding
- SSH with port forwarding
- Launch the JupyterLab server
- Launch JupyterLab in your local browser
Since JupyterLab is a web based application, a port needs to be forwarded to your local machine, where your browser can connect to. This port numbers need to be between 2000 and 65000 and need to be unique on the present machine. The default port for JupyterLab is 8888, but only one user can use this at a time.
To avoid the need for modifying the following procedure again and again, we suggest to (once) select a unique number (between 2000 and 65000). And then following commands can be hopefully reused without modification.
The port needs to be specified while establishing the connection to UBELIX and while launching JupyterLab. In the following we use the port number 15051 (please select another number).
Passwordless SSH within the HPCs
Please verify that you created and registered a SSH key within UBLEIX. If you can perform the following command without entering your password your are ready to go:
ssh-keygen -t rsa -b 4096 # without passphrase cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys chmod 640 .ssh/authorized_keys
Setup SSH with port forwarding
First, the port forwarding needs to be enabled between your local machine and UBELIX. Therewith a local port will be connected to the remote port on UBELIX. This ports are numbers between 2000 and 65000, which needs to be unique on the both sides. The default port for JupyterLab is 8888, but only one user can use this at a time. For simplicity, we kept both numbers the same (here 15051). This can be specified on the command line in the terminal.
ssh command from your local machine to the ubelix login node needs to be called with following arguments:
ssh -Y -L 15051:localhost:15051 <username>@submit.unibe.ch
.ssh/config, you can also use the alias instead of the full name for UBELIX. Where
<username>is you campus account name.
Note: MobaXterm has an internal terminal which acts like a linux terminal and can be configured as described in the Standard Terminal Setup. Therewith, the SSH command line approach above can be used.
Launch the JupyterLab server
On UBELIX, the required Anaconda3 module needs to be loaded. If you want to use additional kernels (R) you need to load additional modules, e.g. IRkernel (for R kernels):
module load Anaconda3
A script is provided, taking care of enabling the port forwarding to the compute node and launching JupyterLab.
jupyter-compute 15051 --time=00:45:00 # please change port number
... [C 21:43:35.291 LabApp] To access the notebook, open this file in a browser: file:///gpfs/homefs/id/ms20e149/.local/share/jupyter/runtime/nbserver-30194-open.html Or copy and paste one of these URLs: http://anode001:15051/?token=69ba5d24acab5915f2520c008a57df51f3cc38b7050ea073 or http://127.0.0.1:15051/?token=69ba5d24acab5915f2520c008a57df51f3cc38b7050ea073
The last line needs to be copied in your local browser.
do not use
Ctrl + C for copying the link, this will abort the server process and kill your job.
jupyter-compute tool uses an special Slurm Quality of Service (QOS), which should reduce queuing times for interactive jobs.
Since interactive jobs are considered to be finished within less than a working day, the walltime limit cannot exceed 8h.
You can disable that qos using the option
--no-qos, but please release the resources as soon as you are not actively working with the resources anymore.
JupyterLab in your local browser
The full address on the last line (starting with the 127.0.0.1) of the Jupyter Server statement including the token needs to be copied into your browser on your local machine. After initializing Jupyter Lab you should see a page similar to:
Therewith the Notebook and its containing tasks are performed on a compute node, which can double check e.g. using using the following in Python:
import socket print(socket.gethostname())
IMPORTANT: Please remember to stop your Jupyter Lab server and therewith your slurm job, when you do not need it anymore. Thus, the resource get available to other users again.
Note: After stopping the JupyterLab server some sessions may get corrupted and do not take input correctly anymore. In this case just quit and re-establish your ssh session.
JupyterLab with multiple CPU cores
More resources can be requested, e.g. by using:
jupyter-compute 15051 --ntasks 1 -t 60 --cpus-per-task 5 --mem 512MB
OR requesting GPU resources on a node with a NVIDIA graphics card:
jupyter-compute 15051 --ntasks 1 -t 60 --partition=gpu --gres=gpu:gtx1080ti:1
Note: This tool can only be used in the all and gpu partition.
The following JupyterLab kernel are installed:
verify that the module IRkernel is loaded
module load IRkernel
There are a long list of default packages provided by Anaconda3 (list all using
!pip list) and R (list using
installed.packages(.Library), note the list is shortened).
Furthermore, you can install additional packages in Python using
pip install --user or in R using