Key Points

Why VS Code Remote?

  • VS Code Remote-SSH provides a full IDE experience for remote HPC development
  • It combines VS Code’s features with direct access to your cluster files
  • VS Code is recommended for serious code development; command-line editors are better for quick edits
  • The Remote-SSH extension creates a seamless local-to-remote development workflow

Installing VS Code

  • Install VS Code from code.visualstudio.com for your operating system
  • Install the Remote-SSH extension by Microsoft from the Extensions sidebar
  • Enable remote.SSH.showLoginTerminal in settings – this is required for DUO

Setting Up SSH Config

  • Configure ~/.ssh/config with a Host sagehen entry and your Pomona username
  • Set proper file permissions (600 for config, 700 for .ssh directory)
  • SSH keys (Ed25519 recommended) are optional but convenient for frequent users
  • Always test ssh sagehen from a terminal before using VS Code Remote-SSH

Connecting to Sagehen HPC

  • Use Remote Explorer to connect to Sagehen and select Linux as the platform
  • remote.SSH.showLoginTerminal must be enabled for DUO prompts to appear
  • After connecting, open /rhome/<myusername> to browse your remote files
  • VS Code automatically attempts reconnection after network interruptions
  • Disconnect via the SSH status button when finished

File Editing Basics

  • Use the Explorer sidebar or Quick Open (Ctrl+P) to navigate remote files
  • Create files with right-click > New File or keyboard shortcuts
  • VS Code provides syntax highlighting and IntelliSense automatically
  • Save with Ctrl+S; files save to Sagehen, not your local machine
  • Drag files from your computer into the Explorer sidebar to upload them

Multi-File Editing

  • Open files appear as tabs; use Ctrl+Tab to switch between them
  • Split editor (Ctrl+\) enables side-by-side editing of two or more files
  • Ctrl+F searches the current file; Ctrl+Shift+F searches across all files
  • Compare files with right-click > Compare to see color-coded differences
  • Manage folders and files directly from the Explorer sidebar

Integrated Terminal

  • The integrated terminal (Ctrl+`) runs on Sagehen, not your local machine
  • The login node is for editing and submission only; use srun for interactive compute
  • Use sbatch to submit jobs and squeue to check status from the terminal
  • Multiple terminal tabs let you edit, submit, and monitor simultaneously
  • Custom terminal profiles can auto-load conda envs or request interactive compute nodes
  • Use tmux to keep interactive sessions alive across VS Code disconnects
  • seff JOBID after job completion reveals over-provisioned resources
  • The edit-submit-monitor workflow makes VS Code ideal for iterative HPC work

Running and Debugging Code

  • Run quick tests directly in the terminal; submit longer jobs through SLURM
  • Use srun for interactive GPU sessions for prototyping
  • tmux sessions persist through disconnections – ideal for long-running monitoring
  • VS Code’s debugger works remotely through Remote-SSH with language extensions
  • The edit-test-submit cycle is the core HPC development workflow

Extensions for HPC

  • Remote extensions run on Sagehen for language support; local extensions handle UI
  • Install Python, R, and Jupyter on the remote side for full language features
  • Extensions persist on Sagehen between sessions
  • Keep 5-10 extensions active to maintain VS Code performance

Customization and Tips

  • Customize themes with Ctrl+K Ctrl+T; customize shortcuts with Ctrl+K Ctrl+S
  • Workspace settings in .vscode/settings.json apply per-project and can be version-controlled
  • Settings Sync keeps your VS Code identical across multiple machines
  • Recommended HPC settings include format-on-save, trailing whitespace trimming, and increased terminal scrollback