January 2026 Maintenance Update
During this month’s scheduled maintenance window, we completed several system upgrades and routine updates across Klone and Tillicum to improve stability, performance, and security. The next maintenance is scheduled for Tuesday, February 10, 2026 (the second Tuesday of the month).
Notable Updates
In addition to routine image updates and security patches, we upgraded:
- Klone login node process enforcement to Arbiter 3 and paused user notifications and Klone and Tillicum (read more below).
- Klone has been upgraded from cgroups v1 to cgroups v2. This upgrade shouldn't be a noticeable for most users, but in some cases memory accounting under cgroups v2 is unified and includes all file-backed page cache. This difference may make memory usage appear higher or "inflated" compared to v1 in niche cases and some specific Java-based applications.
- Slurm version 25.11.1 on both clusters.
- Duo 2FA on Klone (Tillicum already up to date). This change aligns with ongoing UW security upgrades.
All University of Washington technology users must update Duo Mobile to version 4.85.0 or later on all registered devices by February 2, 2026. Users who cannot update their devices must register a platform authenticator, a new phone/tablet, or request a hardware token from UWIT. The Duo phone call authentication method is being phased out by the University and no longer available for logging into Klone or Tillicum.
Login Node Usage & Arbiter Enforcement (Important Reminder)
Login nodes are shared community resources intended for:
- Transferring data
- Navigating the filesystem
- Editing and developing code
- Submitting jobs to the scheduler
As part of this maintenance, Klone was upgraded to Arbiter 3, a tool which automates login node monitoring and enforces usage limits to ensure stability and ensure fair access.
Arbiter monitors resource usage on login nodes and will:
- Slow or halt processes that exceed permitted thresholds.
- Terminate processes outright if necessary.
Arbitor email notifications halted
Previously, users received email notifications for each offending process when Arbiter thresholds were exceeded. We have found these notifications are not an effective way to communicate our policies. To avoid notification fatigue, we have stopped sending these emails.
This does not mean enforcement has stopped. Arbiter continues to actively limit, halt, or kill processes on login nodes as needed.
Connecting directly to the login node using tools like VS Code Remote-SSH frequently leads to Arbiter intervention and could cause login node instability since background server processes persist beyond an active session.
Instead, follow our recommended best practices and set up your ProxyJump to connect your local VS Code to Klone or use the streamlined option offered by our Open OnDemand interactive application for VS Code.
Winter 2026 Computing Workshops
- Linux Command Line Fundamentals Workshop Thursday January 22 10am-12pm
- Using R and RStudio on Hyak Klone Workshop Thursday February 5 10am-12pm
- Managing Python Environments with Conda and Jupyter Thursday March 5 1-3pm
- All workshop have an in person and remote attendance option.
Stay informed by subscribing to our mailing list and the UWIT Research Computing Events Calendar.
Office Hours
- Hyak and Tillicum Office Hours:
- Wednesdays at 2pm on Zoom. Attendees need only register once and can attend any of the occurrences with the Zoom link that will arrive via email. Click here to Register for Wednesday Zoom Office Hours.
- Thursdays at 2pm in person in eScience. (address: WRF Data Science Studio, UW Physics/Astronomy Tower, 6th Floor, 3910 15th Ave NE, Seattle, WA 98195).
- Winter AWS Office hours – AWS solutions architects will be on Zoom to answer your questions and help you troubleshoot.
- See our office hours schedule, subscribe to event updates, and bookmark our UWIT Research Computing Events Calendar.
Additional Training Opportunities
- Applications for the eScience Winter School are due Wednesday, February 4th. This introductory program is for students and researchers from domains such as public and global health, public policy, social sciences, social work, international relations, and business management interested in developing basic skills and knowledge of data science tools like Python, R, and Jupyter.
- COMPLECS: Parallel Computing Concepts 01/15/26 - 11:00am – 12:30pm
- Batch Computing: Working with the Linux Scheduler 02/12/26 - Time: 11:00am – 12:30pm
- Architecting Reproducible Science: A Practical Path Beyond the Notebook 03/10/26 - 11:00am – 12:00pm
- COMPLECS: Data Transfer 03/12/26 - 11:00 a.m. – 12:30 p.m.
- Automate Data and Compute Management Tasks with Globus and ACCESS Resources Mar 19, 2026 11:00 AM
- COMPLECS: Linux Shell Scripting 04/09/26 - 11:00am – 12:30pm
- Fine Tuning Large Language Models (LLMs) with Domain Specific Datasets 04/14/26 - 11:00am – 12:00pm
- COMPLECS: Data Storage and File Systems 04/30/26 - 11:00 a.m. – 12:30 p.m.
- From Atoms to Algorithms: GPU Acceleration of Molecular Dynamics, DFT, and QM/MM Simulations 05/12/26 - 11:00am – 12:00pm
Having trouble? Get Research Computing support.
Happy Computing,
Hyak Team