How to start a session and connect to a User Interface server

User Interface (UI) and Jumphost servers

logins always via jumphost

To submit jobs, check their status, test scripts, etc. you need to login on a User Interface (UI) server using SSH. Each cluster has its own UI and the one for the Nibbler HPC cluster is named nibbler. The UI and various other servers that make up the cluster receive updates during scheduled maintenance, but as this disrupts the processing of jobs, scheduled maintenance is planned only ~twice a year.

Not applying updates for several months could become a serious security risk for machines that are directly accessible via the internet. Therefore the servers of the Nibbler cluster are on an internal network that is not directly accessible from the internet. In order to access the UI you will need to hop via a Jumphost, which is a security hardened machine that is not in any way involved in the processing of jobs nor in storing data and does receive daily (security) updates. In order to apply/activate security patches the Jumphost may be temporarily unavailable, which means you cannot login to the UI and hence cannot manage jobs nor create new ones, but existing jobs (running or queued) won't be affected and the cluster will continue to process those. The Jumphost for the Nibbler HPC cluster is named tunnel

Request an account

First make sure you have an account. If you are new, please follow these instructions to request an account.

SSH client config and log in to UI via Jumphost

Configure your SSH client with the instructions for your operating system: