Monitoring - The fix for the issue was surprisingly easy to deploy.
Users should no longer encounter this issue.
Please let us know at chtc@cs.wisc.edu if you do!

Jan 09, 2026 - 15:27 CST
Update - Slight correction: without "max_idle", you can submit up to 10,000 jobs per submission and you can have up to 50,000 jobs total in the queue. ("Done" jobs generally do not count against the total in the queue.)
Jan 09, 2026 - 14:47 CST
Identified - We've identified an issue where submit files that have "max_idle" (and related keywords) may not create jobs when submitted with "condor_submit".
We have narrowed down the source of the bug, but do not have a fix at this time (and probably not before the weekend).

If you will have less than 10,000 jobs in the queue, we recommend removing this option from your submit file.
If you will more than 10,000 jobs in the queue, you may want to consider removing this option and manually submitting your jobs in batches such that the total number jobs stays under the 10,000 job limit.

We appreciate your patience while we work to deploy a fix for this issue.

Jan 09, 2026 - 13:57 CST
Update - The affected GPU has been removed from the available pool for testing. Unaffected GPUs on the machine are available for use. We are still investigating.
Jan 09, 2026 - 10:35 CST
Investigating - Some jobs landing on xhuanggpu4001 may fail with the message, "uncorrectable ECC error encountered". We have narrowed the issue to a specific GPU. We plan to bring the affected GPU offline for further investigation and fixes, which may require a brief downtime. The machine will be brought back up with the unaffected GPUs available for use.
Jan 07, 2026 - 13:23 CST

About This Site

This page provides information about unplanned downtimes and scheduled maintenance for services offered by the Center for High Throughput Computing

High Throughput Computing (HTC) System Degraded Performance
90 days ago
99.97 % uptime
Today
Access Points Operational
90 days ago
99.89 % uptime
Today
CHTC Pool Degraded Performance
90 days ago
100.0 % uptime
Today
External Pools (OSPool, Campus HTCondor Pools) Operational
90 days ago
100.0 % uptime
Today
Staging and Projects Space Operational
90 days ago
99.99 % uptime
Today
File Transfers Operational
90 days ago
99.95 % uptime
Today
High Performance Computing (HPC) System Operational
90 days ago
99.99 % uptime
Today
Login Nodes Operational
90 days ago
99.98 % uptime
Today
Cluster Nodes and Jobs Operational
90 days ago
100.0 % uptime
Today
Central Software Installations Operational
90 days ago
100.0 % uptime
Today
Home and Scratch File Systems Operational
90 days ago
100.0 % uptime
Today
Data Transfer Tools Operational
90 days ago
100.0 % uptime
Today
Globus Endpoint Operational
90 days ago
100.0 % uptime
Today
CHTC Internal Infrastructure Operational
90 days ago
100.0 % uptime
Today
Tiger Cluster Operational
90 days ago
100.0 % uptime
Today
RT Email/Ticket Support System Operational
90 days ago
100.0 % uptime
Today
Operational
Degraded Performance
Partial Outage
Major Outage
Maintenance
Major outage
Partial outage
No downtime recorded on this day.
No data exists for this day.
had a major outage.
had a partial outage.

Scheduled Maintenance

DSI GPU Maintenance Jan 14, 2026 07:00-18:00 CST

We will be upgrading the DSI GPUs on this date.
Posted on Jan 07, 2026 - 16:26 CST
Jan 11, 2026

No incidents reported today.

Jan 10, 2026

No incidents reported.

Jan 9, 2026

Unresolved incidents: [HTC] "max_idle" jobs not entering queue, [HTC] ECC errors on xhuanggpu4001.

Jan 8, 2026

No incidents reported.

Jan 7, 2026
Jan 6, 2026

No incidents reported.

Jan 5, 2026

No incidents reported.

Jan 4, 2026

No incidents reported.

Jan 3, 2026

No incidents reported.

Jan 2, 2026

No incidents reported.

Jan 1, 2026

No incidents reported.

Dec 31, 2025

No incidents reported.

Dec 30, 2025

No incidents reported.

Dec 29, 2025

No incidents reported.

Dec 28, 2025

No incidents reported.