Interactive Sessions¶
CANFAR computing environments for astronomical research - Jupyter notebooks, and non-interactive applications.
🎯 Session Types Overview
Choose the right interface for your research:
- Jupyter Notebooks: Interactive data analysis and visualisation
- Desktop Environment: Full Linux desktop with GUI applications
- CARTA Viewer: Radio astronomy visualisation and analysis
- Firefly Viewer: Table and image viewing for surveys
- Contributed Apps: Specialised community applications
- Batch Processing: Automated and large-scale workflows
🚀 Session Fundamentals¶
What are Interactive Sessions?¶
Interactive sessions provide on-demand access to pre-configured computing environments running in containers. Each session type offers different interfaces optimised for specific astronomical workflows.
Key Benefits¶
- No Installation Required
- Access complex astronomy software through your web browser without local installation or configuration.
- Pre-Configured Environments
- Containers include popular astronomy packages like AstroPy, CASA, and scientific Python libraries ready to use.
- Persistent Data Access
- All sessions automatically connect to your ARC storage and can access VOSpace for long-term data management.
- Scalable Resources
- Choose flexible or fixed resource allocation based on your computational requirements.
📊 Session Type Comparison¶
| Session Type | Interface | Best For | GUI Support |
|---|---|---|---|
| Notebook | JupyterLab | Data analysis, prototyping, documentation | ✅ Web-based |
| Desktop | Full Linux desktop | CASA, image viewers, traditional software | ✅ Desktop GUI |
| CARTA | CARTA interface | Radio astronomy visualisation | ✅ Specialised |
| Firefly | Firefly viewer | Catalogue analysis, image display | ✅ Web-based |
| Contributed | Various | Specialised applications | ⚠️ Varies |
| Batch | None (headless) | Large-scale processing | ❌ Headless |
🔧 Session Management¶
Creating Sessions¶
- Via Science Portal:
- Launch sessions through the CANFAR Science Portal web interface with point-and-click simplicity.
- Via Command Line:
- Use the CANFAR CLI for scripted session creation and automation.
- Via Python API:
- Integrate session management into custom workflows using the CANFAR Python Client.
Session Lifecycle¶
- Creation (30 seconds - 3 minutes)
- Container download (first time) and startup with storage mounting
- Active Use
- Full access to computing resources and storage systems
- Idle Management
- Sessions automatically suspend after periods of inactivity to conserve resources
- Termination
- Container deletion with data preserved in persistent storage
Data Persistence
Important: Session containers are temporary. Always save important work to /arc/ storage or VOSpace before ending sessions.
📈 Resource Allocation¶
Flexible Allocation (Default)¶
Advantages: - Faster session startup - Can burst to higher resource usage when available - Optimal for interactive work and development
Best For: - Data exploration and analysis - Development and testing - Educational workshops
Fixed Allocation¶
Advantages: - Guaranteed consistent performance - Predictable resource availability - Better for production workloads
Best For: - Large-scale processing - Performance-critical analysis - Time-sensitive computations
Resource Selection Guide¶
| Workflow Type | Recommended Mode | CPU/Memory | Duration |
|---|---|---|---|
| Interactive Analysis | Flexible | 2-4 CPU, 4-8GB | Hours |
| Large Dataset Processing | Fixed | 4-8 CPU, 16-32GB | Hours-Days |
| Development & Testing | Flexible | 1-2 CPU, 2-4GB | Hours |
| Production Pipelines | Fixed | Varies by workload | Days |
🔗 Integration with Platform Services¶
Storage Integration¶
All interactive sessions automatically mount:
- ARC Home (
/arc/home/[user]/): Personal configurations and scripts - ARC Projects (
/arc/projects/[project]/): Shared research data and results - Scratch (
/scratch/): High-speed temporary storage for processing
Additional storage accessible via API:
- VOSpace (vos:): Long-term archives and data sharing
Container Environments¶
Sessions run in container environments that include:
- Operating system (typically Ubuntu Linux)
- Astronomy software packages (AstroPy, CASA, etc.)
- Scientific computing libraries (NumPy, SciPy, Matplotlib)
- Development tools and utilities
Authentication & Permissions¶
Sessions inherit your CANFAR permissions:
- Automatic access to your group projects
- Secure integration with CADC services
- API access for automated workflows
🎯 Choosing Your Session Type¶
For Data Analysis¶
- New to CANFAR? → Start with Jupyter Notebooks
- Familiar interface combining code, documentation, and visualisation
- Need GUI Applications? → Use Desktop Sessions
- Full Linux desktop for CASA, image viewers, and traditional software
For Astronomy Specialisations¶
- Radio Astronomy → CARTA Viewer
- Optimised for radio interferometry data visualisation and analysis
- Survey Data → Firefly Viewer
- Efficient table and image viewing for large astronomical catalogues
- Specialised Tools → Contributed Applications
- Community-maintained applications for specific research domains
For Production Work¶
- Large-Scale Processing → Batch Sessions
- Automated workflows for processing large datasets without interactive interfaces