2026-03-11 –, Main Hall
The EuroHPC Federation Platform is a project to federate access to EuroHPC systems, to make it
easier for researchers and industry users across Europe to access computing resources. Within
the project, a federated instance of Open OnDemand has been developed and deployed. It has many
unique features and integrations, such as remote cluster file system access, Kubernetes-native
deployment, and integration of the EESSI software stack.
This talk targets system administrators, service owners, and others interested in federation of HPC
resources or responsible for maintaining and developing Open OnDemand instances. It discusses
technical details and challenges of providing a single instance of Open OnDemand which is
connected to multiple supercomputers at external organizations.
Open OnDemand (OOD) is used in the EuroHPC Federation Platform (EFP) to provide interactive
web-based access to EuroHPC computing resources. Although OOD is normally deployed for use with a
single supercomputer, the OOD instance in EFP has been developed to be a central instance of OOD
that connects to externally managed EuroHPC systems purely over SSH. As a result, the users can
access any of the available EuroHPC systems from the same instance. The OOD instance in EFP
depends on many other components in the platform, including the federated user authorization and
authentication infrastructure, resource allocation, SSH CA, and the European Environment for
Scientific Software Installations (EESSI) software stack.
Two major features for OOD have been developed to make the federated instance possible, both of
which will be contributed upstream. The first is a remote cluster file system feature, which enables
OOD to access the file system of the cluster over SSH rather than local mounts. It also enables the
possibility of implementing other methods of file system access, such as FirecREST, in the future.
The other feature, Kubernetes-native deployment, allows configuring OOD to schedule each per-
user nginx instance in its own Kubernetes pod. As a result, OOD is more suited for being deployed
in a Kubernetes cluster, with increased user isolation, better horizontal scalability, and with less
privileges needed.
As the federated instance of OOD connects to many different systems with different software stacks,
EESSI is used to provide a common software stack. The EESSI integration includes module selection
as well as interactive apps with zero dependencies on the local supercomputer software stack.
Several commonly used software applications used in interactive apps were added to the EESSI
repository within the project, which are now available for anyone to use.
This talks builds on the “Federated Open OnDemand” talk from GOOD25, by discussing how the
previously presented prototypes and ideas became reality, with the EuroHPC Federation Platform
going into production in March 2026. The talk will provide a foundation of ideas, challenges, and
other insight for anyone interested in connecting multiple supercomputers to OOD, deploying OOD
outside of the cluster itself, deploying in Kubernetes, or using EESSI to provide the software for
OOD interactive apps.
Developing the Open OnDemand instances at CSC, consisting of Open OnDemand for the national systems Puhti, Mahti and Roihu, the EuroHPC system LUMI, and Open OnDemand in the EuroHPC Federation Platform.