Requirements

This page lists what a Slurm cluster must provide for Cybershuttle. The centre installs nothing: CS Bridge and Airavata download Linkspan into each user's home directory on first use, and everything runs as that user. Preparing the cluster shows how to meet each requirement and verify it.

CS Bridge is tested on the clusters in Tested clusters. CS Jupyter and batch runs have no list of tested clusters.

The figure shows every connection that crosses the cluster's boundary. Each arrow points from the side that opens the connection; none points into a compute node. Unlabelled arrows are HTTPS; the link is the WebSocket that Linkspan dials to Airavata, which the Jupyter client uses by default.

Login node

Cybershuttle drives Slurm from the login node over SSH. For interactive sessions, CS Bridge and Airavata's session server log in as the user and run the commands below; a missing command fails the step that uses it.

Command	Used for
sacctmgr	Listing the user's Slurm associations
sinfo	Listing partitions, CPUs, memory and GPU GRES
sbatch	Validating (--test-only) and submitting
squeue, sacct	Job state and accounting
scancel	Stopping a session
srun --overlap	Sampling usage in a running job (VS Code, when the tunnel is not attached)
curl, tar, base64, od, install, printenv, sed, sort -V, standard POSIX tools	Installing Linkspan and writing job files

Where /usr/local/etc/project.map exists, as on TACC systems, CS Bridge reads it to spell Slurm account names as the site's submit filter expects. Airavata runs these commands without a login profile, so they must be on the PATH of a non-interactive shell; Accounts and SSH login gives the check, what batch runs need and how each login authenticates.

Compute nodes

A session job runs Linkspan, which starts the SSH or Jupyter server and takes usage readings. Batch runs need nothing on compute nodes beyond what the application itself uses.

Requirement	Needed for
Linux on x86_64 or arm64	Running Linkspan; no other architecture is released
$HOME shared with the login node	Running Linkspan and job files installed from the login node; reading the job's logs there
A writable $HOME	Everything under $HOME/.cybershuttle; with a full quota the job exits before Linkspan starts
curl	Installing uv for Jupyter
cgroup v2	CPU and memory readings; optional, empty without it
nvidia-smi	GPU readings; optional, empty without it

Network egress

No inbound port to a compute node is needed. Apart from job e-mail, every connection from the cluster is outbound HTTPS (TCP 443), so an allowlist of these names suffices.

From	To	For
Login node	github.com, release-assets.githubusercontent.com	Downloading Linkspan
Compute node	jupyterapi.cybershuttle.org	The link transport (Jupyter default)
Compute node	*.devtunnels.ms, *.rel.tunnels.api.visualstudio.com, tunnelsassetsprod.blob.core.windows.net	The Dev Tunnel transport (VS Code default)
Compute node	release-assets.githubusercontent.com, github.com, astral.sh, pypi.org, files.pythonhosted.org	Building the Jupyter environment on first use

jupyterapi.cybershuttle.org is the public Airavata instance; a centre that hosts its own allows its own public name instead. Airavata also reaches each login node on its SSH port.

CS Bridge and Airavata check GitHub for the latest Linkspan release before each start. When GitHub is unreachable they keep an installed ~/.cybershuttle/bin/linkspan of version 0.22.0 or newer; with none installed, the start fails.

Compute nodes need direct egress or NAT; the link transport ignores HTTPS_PROXY. Network egress gives the check.

Job e-mail

Batch runs only. Airavata's batch server learns a job's state only from Slurm's job e-mail, not from squeue or sacct. Every batch job script sets:

Option	Value
--mail-user	The batch server's mailbox, a Gmail inbox it reads over IMAP
--mail-type	BEGIN, END, FAIL, REQUEUE, INVALID_DEPEND, STAGE_OUT and the TIME_LIMIT events

Slurm's MailProg must deliver job e-mail to external addresses. Without it, runs are submitted but never reported as started or ended, and their outputs are not copied back. Job e-mail for batch runs gives the steps.