Sign-In & Session Problems¶

This page covers common failures to reach or start a session on datahub.ucsd.edu and their remedies, most of which are self-service.

Campus Sign-In Failures¶

Datahub sign-in is standard UCSD single sign-on. An account that cannot get past the campus sign-in page has a campus credential problem, not a Datahub problem, and the ITS Service Desk handles it.

Missing Course¶

Sign-in succeeds, but the expected course does not appear. A missing course is a provisioning matter, not an access fault.

Roster Loading and TSS Changes¶

Rosters are loaded into workspaces one business day before the start of the term, and a TSS change, such as an add, a drop, or a section change, is reflected in Datahub and DSMLP by 10am the day following the change. A course that is not listed before those times has not been loaded yet. Report a course that is still missing after that time to datahub@ucsd.edu. Roster provisioning is described in Students Enrolled in a Course.

Roster Checks by Course Staff¶

The instructor or TA is the first contact for a course matter. Course staff can see the roster and can tell a student who is not yet enrolled from one who is enrolled but not provisioned. Auditors, observers, and Extended Studies students are not on the TSS roster that the automatic setup uses, and the instructor adds them through Canvas, as described in Students Enrolled in a Course.

Access Outside a Course¶

No roster grants access for an independent study, a capstone, or a personal project. Access for this work is obtained by request, as described in Projects & Independent Study.

"Spawn Failed"¶

The account is signed in and an environment has been selected, but the environment does not start. Check four causes in order: a Datahub session already running, a full disk quota, a stale profile, and a broken package in .local.

Datahub Session Already Running¶

A member may have one Datahub session at a time, and shell, VS Code, and batch jobs do not count toward that limit, as described in Concurrent Datahub Sessions. A session left running, for this course or another, must be stopped before a new one starts. Stop it with File → Hub Control Panel → Stop My Server. Where the running session cannot be reached, use the manual resetter described in Stale Profile and the Manual Resetter.

Full Disk Quota¶

A full disk quota prevents a session from starting and produces no error message. The quota is shown at datahub.ucsd.edu/hub/spawn → Services → disk-quota-service. Storage quotas are described in Workspace and Personal Quotas.

Stale Profile and the Manual Resetter¶

The manual resetter is provided for a stale profile. It stops any running servers, signs the account out, and resets the profile. Files are preserved.

1. Open datahub.ucsd.edu.
2. Open the services dropdown and choose manual-resetter.
3. Click reset.

Broken Package in .local¶

Packages under .local/lib/python3.x/site-packages load ahead of the packages the image provides, and one incompatible package can stop a notebook from starting. Move them aside from a terminal:

ssh USERNAME@dsmlp-login.ucsd.edu
workspace --list                  # the workspaces available to the account
workspace -c COURSE_ID            # enter the course workspace
mv .local/lib .local/lib.old      # move the offending packages aside

Install packages into a virtual environment rather than into .local. Installing packages is described in Customizing an Environment.

Unexplained Spawn Failures¶

The cause of a spawn failure not explained by a running session, a full quota, a stale profile, or a broken .local package is not yet documented. Report such a failure with the time and the course, as described in Reporting a Problem.

Links Clicked Before Sign-In¶

Course materials are often distributed by a link that fetches a repository into the course environment:

https://datahub.ucsd.edu/hub/user-redirect/git-pull?repo=<url-encoded>&urlpath=tree%2F<dir>%2F&branch=main

The most common failure of such a link is a click before sign-in. The link needs a signed-in session to redirect into. Without one, it fails in a way that resembles a broken link.

To open the link:

1. Sign in at datahub.ucsd.edu.
2. Start the course environment.
3. Click the link.

Clicking a failed link again after signing in also works.

See also: Grading

Launches Refused by the Cluster¶

GPU Held by an Existing Pod¶

A launch that reports an exceeded GPU quota indicates that a pod on the same account already holds the requested GPU. The earlier pod is usually terminating and clears within a minute or two. If it does not clear, delete it from the login node:

ssh USERNAME@dsmlp-login.ucsd.edu
kubectl get pods
kubectl delete pod <pod-id>

Aggregate Resource Limits¶

Concurrent sessions are permitted, but their combined CPU, memory, and GPU must fit within the Kubernetes limits on the namespace and, for GPUs, within the reservation system's limits. A launch that would take the total past those limits is refused. The remedy is to stop a session or job that is no longer in use. No request is required. Running several jobs together is described in Running Several Jobs at Once.

504 Error After a Crash¶

A notebook that exhausts its memory or runs an infinite loop can take its pod down. The hub then returns a 504 error until it detects the failure and resets. To recover:

1. Delete the pod with kubectl delete pod, as described in GPU Held by an Existing Pod. This shortens the wait for the hub to reset.
2. Run the manual resetter, as described in Stale Profile and the Manual Resetter.
3. Start the session again.

Error messages and their causes are listed in Error Messages.

Sessions Left Running After Sign-Out¶

Stop the session with File → Hub Control Panel → Stop My Server, as described in Stopping a Session.

Reservation App Sign-In¶

The reservation app at reserve.dsmlp.ucsd.edu uses UCSD single sign-on, like Datahub, but keeps its own session.

Expired Reservation App Sessions¶

A reservation app session ends after 8 hours without use, and 24 hours after sign-in in any case. Log out everywhere ends it on every device at once. The app then returns to its login page with no message, and a booking that was being made in the wizard is lost. Sign in again and start the booking again.

Sign-In Errors Shown as Text¶

A failed sign-in shows a line of text in the browser tab rather than a page:

HTTP 422 in the Reservation App¶

HTTP 422 in a form means the app rejected one of the values sent, most often a blank field. Fill in every field and try again.

End of Course Access¶

Course access is retained for a period beyond the term the course ran in, as described in One Additional Quarter. After that period, the course no longer appears, and its absence is not a fault. Files remain retrievable for a period afterward, and an extension can be requested. Copying files out is described in Retrieving Work Before Access Ends.

Reporting a Problem¶

Raise course matters with the instructor or TA first. For platform matters, email datahub@ucsd.edu or file a ticket with the ITS Service Desk. A report includes the following details:

• The course
• The system in use (Datahub or dsmlp-login)
• The environment name
• The exact command, if there was one
• A screenshot

Response targets for individual issues are listed in Response Targets.

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