Interactive Sessions with sinteractive¶

The sinteractive script launches a persistent interactive session on a compute node using tmux. It's located at scripts/sinteractive in this repository.

Why use sinteractive instead of srun --pty bash?¶

Installation¶

make install

This copies the script to ~/.local/bin/. Make sure ~/.local/bin is in your $PATH (add export PATH="$HOME/.local/bin:$PATH" to your ~/.bashrc if needed).

To install to a different location:

make install PREFIX=~/bin

Usage¶

sinteractive [OPTIONS] [SBATCH_ARGS...]

Options¶

All other arguments are passed directly to sbatch, so you can use any sbatch option.

Examples¶

# Default: 8-hour session, 2 CPUs, 8G memory
sinteractive

# Run on a specific node
sinteractive --node compute01

# 2-hour session on the rna partition
sinteractive --time=2:00:00 --partition=rna

# Override default memory and CPUs
sinteractive --mem=16G --cpus-per-task=4

# GPU session
sinteractive --partition=gpu --gpus=1 --mem=16G

# Longer session on the normal partition (up to 3 days)
sinteractive --time=1-12:00:00 --partition=normal

How it works¶

1. Submits a batch job — sbatch launches the script itself on a compute node, where it starts a tmux session.
2. Waits for the job to start — polls squeue every 5 seconds until the job is running (you'll see dots printed while waiting).
3. Connects via SSH — once running, it SSHs into the compute node with X11 forwarding (-X) and attaches to the tmux session.
4. Stays alive until you exit — the SLURM job remains running as long as the tmux session exists. Detaching (Ctrl-b d) or losing your SSH connection leaves the job running so you can reconnect. Exiting tmux (exit) ends the job.

sequenceDiagram
    participant L as Login Node
    participant S as SLURM
    participant C as Compute Node

    L->>S: sbatch (submit job)
    S->>C: start tmux session
    L-->>L: poll squeue until RUNNING
    L->>C: ssh -X (attach to tmux)
    Note over C: you work here

Reconnecting after a disconnect¶

If your SSH connection drops or you intentionally detach (Ctrl-b d), the tmux session keeps running on the compute node and your work is safe. To reconnect from the login node:

# List your running sessions
sinteractive --list
#   JOBID       NODE            ELAPSED     TIMELIMIT
#   12345       compute01       01:23:45    08:00:00

# Reattach
sinteractive --attach 12345

Tips¶

Basic tmux commands¶

Cancelling the job¶

Exiting the tmux session (type exit or Ctrl-d in all panes) automatically cancels the SLURM job. You can also cancel it directly:

scancel <JOBID>