---
title: Jupyterhub on Merlin7
#tags: 
keywords: jupyterhub, jupyter, jupyterlab, notebook, notebooks
last_updated: 24 July 2025
summary: "Jupyterhub service description"
sidebar: merlin7_sidebar
permalink: /merlin7/jupyterhub.html
---

Jupyterhub provides [jupyter notebooks](https://jupyter.org/) that are launched on
cluster nodes of merlin and can be accessed through a web portal.

## Accessing Jupyterhub and launching a session

The service is available inside of PSI (or through a VPN connection) at

**<https://merlin7-jupyter01.psi.ch:8000/hub/>**


   1. **Login**: You will be presented with a **Login** web page for
      authenticating with your PSI account.
   1. **Spawn job**: The **Spawner Options** page allows you to
      specify the properties (Slurm partition, running time,...) of
      the batch jobs that will be running your jupyter notebook. Once
      you click on the `Spawn` button, your job will be sent to the
      Slurm batch system. If the cluster is not currently overloaded
      and the resources you requested are available, your job will
      usually start within 30 seconds.

### Recommended partitions

Running on the `merlin7` cluster and using the `interactive` partition would
in general guarantee fast access to resources. Keep in mind, that this partition
has a limit of 12 hours.

## Requesting additional resources

The **Spawner Options** page covers the most common options. These are used to
create a submission script for the jupyterhub job and submit it to the slurm
queue. Additional customization can be implemented using the *'Optional user
defined line to be added to the batch launcher script'* option. This line is
added to the submission script at the end of other `#SBATCH` lines. Parameters can
be passed to SLURM by starting the line with `#SBATCH`, like in [Running Slurm
Scripts](../03-Slurm-General-Documentation/slurm-examples.md). Some ideas:

**Request additional memory**

```
#SBATCH --mem=100G
```

**Request multiple GPUs** (gpu partition only)

```
#SBATCH --gpus=2
```

**Log additional information**

```
hostname; date; echo $USER
```

Output is found in `~/jupyterhub_batchspawner_<jobid>.log`.

## Contact
In case of problems or requests, please either submit a **[PSI Service
Now](https://psi.service-now.com/psisp)** incident containing *"Merlin
Jupyterhub"* as part of the subject, or contact us by mail through
<merlin-admins@lists.psi.ch>.