Computing environment

SSH security updates for cryptography options, 12.1.2024

Recently, a new SSH vulnerability called Terrapin (CVE-2023-48795) was published describing weaknesses in the key exchange when using certain ciphers. Consequently, the login nodes on Puhti and Mahti have been updated to disallow the use of the weak ciphers: chacha20-poly1305@openssh.com and any EtM cipher variants. This change was deployed on Friday 12.1.2024 around 13 o'clock Finnish time.

This change seems to have triggered many Windows OpenSSH clients to use a cipher and MAC algorithm combination, which does not work. The result is a message saying "Corrupted MAC on input". This is a known issue on Windows, and can be worked around by adding explicit options for which MAC algorithms to use.

Please refer to our FAQ page about the issue for details.

Mahti web interface updated to release 3, 12.12.2023

Handling of reservations has been improved.
- Future reservations are now shown.
- All reservations can now be used on any app regardless of partition.
- Reservation caching has been improved to be more up to date.
- Job time is now limited by reservation length automatically.
Jupyter for Courses now also allows specifying reservation in the course environment YAML.
Jupyter for Courses and TensorBoard now show errors if the module or log path are left empty.
Web interface session lifetime has been increased to 12h from the previous 8h.
Umask is now set correctly. This affects files created using the file browser.
The browser cache is now validated more frequently to avoid issues after updates.

The LUMI web interface has been released, 9.11.2023

The brand new LUMI web interface has been released at www.lumi.csc.fi! The LUMI web interface offers the same capability as the Mahti and Puhti web interfaces. Read more in the LUMI documentation.

Mahti web interface updated to release 2, 13.10.2023

MLflow Tracking is now available as an interactive app.
An Allas configuration tool has been added for configuring a connection to Allas.
IDA is now supported in the file browser.
The Desktop app configuration and icons are now saved between sessions.
VSCode updated to 1.82.2.
Jupyter notebooks in VSCode now work.
Usage metrics now include a description.
Open OnDemand updated to version 3.0.3.

Puhti web interface updated to release 17, 8.9.2023

MLflow Tracking is now available as an interactive app.
Jupyter now has the qiskit module available.
Changes in the Desktop app:
- The desktop configuration is now saved between sessions.
- The MATE desktop environment and single application launch has been removed.
MATLAB updated to r2023a.
VSCode updated to 1.80.2.

Puhti web interface updated to release 16, 4.7.2023

RStudio now has r-env 4.3.0 available.
Blender updated to 3.6.0 with added support for add-on installation.
Web interface session lifetime has been increased to 12h from the previous 8h.

Mahti web interface available, 13.6.2023

The web interface, previously available for Puhti only, is now available also for Mahti at www.mahti.csc.fi. Apps available in the Mahti web interface:

Active Jobs
Compute and Login node shell
Desktop with Maestro and VMD
Disk quotas and Project view
File browser with support for Allas
Jupyter, Julia-Jupyter and Jupyter for courses
TensorBoard
Visual Studio Code

New policy on Puhti and Mahti for projects that have run out of billing units, 22.5.2023

In addition to limiting access to compute resources upon running out of billing units, now also access to storage will be limited on Puhti and Mahti. Please read running out of billing units for more details. To give all projects time to react, the policy will be enforced starting June 21, 2023. Please login to MyCSC to check if you have projects that have a negative amount of billing units. When logging in to Puhti using ssh or the web interface you will also receive warnings and information on how much time remains before access is removed.

Puhti web interface updated to release 15, 2.5.2023

A new Julia-Jupyter app is now available.
Visual Studio Code app has received updates.
- Support for Julia language features was added.
- VSCode version 1.76.1 is now available.
- Version may be selected when launching the app.
Puhti usage metrics now include history (expand by clicking the chevron).
Open OnDemand version updated to 2.0.32.

Puhti web interface updated to release 14, 2.2.2023

Xfce is now the main desktop alternative and other options are being deprecated
Removed MOTD from the frontpage
All terminals in the desktop now open outside the container -> should work exactly as a normal login shell
Host terminal has been renamed Terminal on the desktop
Graphical Emacs now available in the desktop
Jupyter app now accepts full path to Python interpeter, enabling direct usage of Tykky installations.
Time left for job is now correctly calculated and displayed at the bottom of the terminal when reconnecting to a compute node shell.

Puhti disk cleaning policy changed, 17.1.2023

Usage policy changed, now files not accessed in 6 months are deleted in the cleaning process.

Puhti web interface updated to release 13, 20.12.2022

New visual style.
A logout page now informs users about how to securely log out of Puhti web interface.

Puhti web interface beta updated to release 12, 10.11.2022

User authentication is now happening through OpenID Connect, which means that users can authenticate via Haka or CSC login. This enables Single Sign-on (SSO) between, e.g., the web interface and My CSC.
A new welcome page has been added instead of the old login page.
The Puhti usage metrics are now visualized in a new manner.
Open onDemand version updated to 2.0.29.

Two new login nodes, puhti-login14.csc.fi and puhti-login15.csc.fi, have been added to Puhti and included to the round-robin DNS of puhti.csc.fi. Use the command ssh <username>@puhti-login<11-12,14-15>.csc.fi if you need to connect to a specific login node, e.g. ssh kkayttaj@puhti-login14.csc.fi.

Puhti operating system updated to RHEL8, 5.10.2022

The operating system of Puhti has been updated from Red Hat Enterprise Linux (RHEL) 7 to RHEL 8.

Pre-installed software and libraries as well as the documentation have been updated
Default compiler stack is now gcc/11.3.0, openmpi/4.1.4 and intel-oneapi-mkl/2022.1.0. See more details.
Note that hpcx-mpi has been removed and replaced by openmpi
Users should recompile their own codes for the new OS
Some older versions of applications are not available anymore

Please note that old login nodes (puhti-login1 and puhti-login2) are no longer available. The new login nodes have been renamed as puhti-login11 and puhti-login12. Also, the ssh keys of the login nodes have changed and the checksums of the new keys are:

SHA256 checksum	Key
kk0Tar9opQ+6Gq0GWJdWVVvFEMeI6kW1DW1VOYveT5c	ssh_host_ecdsa_key.pub (ECDSA)
Q2lpykI43ffs4PrRODZ/qncjUo3eyrRHc5T9yjJEwWY	ssh_host_ed25519_key.pub (ED25519)
WH1Ag2OQtMPZb+hj3YeH9uVMMetXpCvyNUbsdk0Qcpk	ssh_host_rsa_key.pub (RSA)

When logging into puhti.csc.fi for the first time after the RHEL8 upgrade, you will encounter a warning saying "WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!". This is completely expected, and you do not need to worry about it. The warning will disappear if you remove puhti.csc.fi from your known_hosts file. You can run the following command: ssh-keygen -R puhti.csc.fi or you can remove the offending line with your favorite text editor. The warning message will print which line number is the problematic one.

After removing the offending line, login again as normal, check that the fingerprint that is offered by the server matches one of the above checksums, and type "yes" to continue connecting. After this you should be able to connect to puhti.csc.fi normally.

Puhti web interface beta updated to release 10 24.8.2022

A new MATLAB app has been added.
Blender has been added to the Accelerated Visualization app.
Improved form validation messages.
Improved Jupyter app launch form.
pytorch module now launches correctly in Jupyter app.
Fixed Jupyter Lab not working in Jupyter for Courses.
Updated VS Code to 1.70.1.
Open onDemand version updated to 2.0.28.

Puhti has been updated with additional local disks on Big Mem nodes, 6.7.2022

Fast local NVMe disks can be used to speed up single node workloads that do a lot of read and write operations on data sets that fit on the disks. Especially small reads and writes, and operations on a large amount of files are much faster on the local disks than on the parallel file system. Now also the 6 nodes with 1.5 TiB of memory have been upgraded with 5960 GiB local disks. See Puhti technical details for a detailed list of all nodes.

Puhti web interface beta updated to release 9 5.7.2022

Added graphs showing Lustre usage metrics to dashboard.
Improved web interface performance, especially during heavy Lustre load.
Modules selected when launching apps are now shown on the active sessions page.
Local disk must now be used when running RStudio.
Updated VS Code to 1.66.2.
Open onDemand version updated to 2.0.27.

How to clean up data - automatic removal, new tools and instructions 10.6.2022

Puhti's parallel file system is filling up and hence degrading performance. We will start to enforce a policy to remove old files. To help managing files without causing excessive load on the system, we've updated our tutorial on how to move, delete or archive your data.

Puhti web interface beta updated to release 8 25.5.2022

A new Accelerated Visualization app has been added for running applications with GPU acceleration.
Improved the main dashboard page layout.
Improved login page layout.
Added more visible warnings about home directory quota.
Added CSC User guides links to all apps.
Open onDemand version updated to 2.0.24.

Puhti has been updated with additional local disks, 13.5.2022

Fast local NVMe disks can be used to speed up single node workloads that do a lot of read and write operations on data sets that fit on the disks. Especially small reads and writes, and operations on a large amount of files is much faster on the local disks than on the parallel file system. Now 48 nodes with 192 GiB of memory, and 12 nodes with 768 GiB of memory have been equipped with local disks that have a size of 1490 GiB. Later in 2022 all the big memory nodes with 1,5TiB of memory will be upgraded with 6 TiB disks. These are in addition to the original 40 CPU nodes and 80 GPU nodes with 3600 GiB NVMes. See Puhti technical details for a detailed list of all nodes.

Mahti operating system updated to RHEL8, 4.5.2022

The operating system of Mahti has been updated from Red Hat Enterprise Linux (RHEL) 7 to RHEL8.

Pre-installed software and libraries including the documentation have been updated.
Users should also recompile their own codes for the new OS.
Some older versions of applications are not available anymore.

Please note that old login nodes (mahti-login1 and mahti-login2) are not available and new login nodes also have new names, mahti-login11 and mahti-login12. Also the ssh keys of login nodes have changed and check sums of new keys are:

SHA256 checksum	Key
WC9Lb5tmKDzUJqsQjaZLvp9T7LTs3aMUYSIy2OCdtgg	ssh_host_ecdsa_key.pub (ECDSA)
tE+1jA4Et1enbbat1V3dMRWlLtJgA8t7ZrkyIkU4ooo	ssh_host_ed25519_key.pub (ED25519)
0CxM3ECpD2LhAnMfHnm3YaXresvHrhW4cevvcPb+HNw	ssh_host_rsa_key.pub (RSA)

When logging into mahti.csc.fi for the first time after the RHEL8 upgrade, you will encounter a warning saying "WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!". This is completely expected, and you do not need to worry about it. The warning will disappear if you remove mahti.csc.fi from your known_hosts file. You can run the following command: ssh-keygen -R mahti.csc.fi or you can remove the offending line with your favourite text editor. The warning message will print which line number is the problematic one.

After removing the offending line, log in again as normal, check that the fingerprint that is offered by the server matches one of the above checksums, and type "yes" to continue connecting. After this you should be able to connect to mahti.csc.fi normally.

Puhti web interface beta updated to release 7 23.3.2022

Jupyter for courses app now supports creating course environments for projects.
Added Puhti usage graphs to dashboard.
Added cookie policy and accessibility statement pages.
Some UI fixes and small bug fixes.
Open onDemand version updated to 2.0.23.

Puhti web interface beta updated to release 6 2.2.2022

Possible to select slurm reservation for applications
New Jupyter app for courses.
Open onDemand version updated to 2.0.22.

Puhti web interface beta updated to release 5

Added new TensorBoard app for visualizing TensorFlow runs.
When launching apps, only partitions available for the selected project are visible now.
Rclone app has been removed.
Open onDemand version updated to 2.0.20.

Puhti web interface beta updated to release 4 30.11.2021

Can now use custom python environments for Jupyter notebooks, see Jupyter documentation.
Added new Compute node shell app that gives a persistent shell on a compute node for commands that should not be run on login nodes.
App cards show more information about resource usage after job has finished (seff output)
Can reset interactive forms to default settings
Rclone app now alerts about missing Allas authentication
Added terminal outside container to Desktop app
Quota and BU warnings can now be hidden
Open onDemand version updated to 2.0.19

Puhti web interface beta updated to release 3 9.11.2021

App cards show more information about resources and reason for shutting down the app to help troubleshoot issues.
Various app improvements, especially Rclone.
Increased timeouts for launching apps.
Login fails now show an error message.

Puhti web interface beta (release 2) is available 18.10.2021

An easy-to-use web interface for Puhti is now open for beta test use at https://www.puhti.csc.fi. The new user interface offers an easy way for new users to use Puhti, and for experienced users it makes access to some features quicker and easier. See web interface for details

MPICH modules no longer work 4.5.2021

As a consequence of the major network stack update done on Puhti during the service break, the MPICH installations on Puhti no longer work correctly and can not be easily fixed. Old versions of MPICH were installed as a last-resort option and they were using a communication library that has now been deprecated by the vendor. We advice you to recompile your software using either hpcx-mpi or intel-mpi. Please let us know if for some reason you can not at all work with either of the above mentioned mpi libraries.

MPICH version 3.4 with UCX support is going to be installed on Puhti later, but this will take some time.

Slurm update and srun & behavior 4.5.2021

Running srun prog & on Puhti will produce errors like "step creation still disabled, retrying (Requested nodes are busy)" if SLURM_EXACT=1 or SLURM_OVERLAP=1 is not set. See https://slurm.schedmd.com/srun.html for details