# Using Compute Canada / ACENET HPC

This guide explains how to connect to the Digital Research Alliance of Canada (Compute Canada) or ACENET clusters, create a working directory in scratch, transfer files with Globus, and submit jobs using SLURM.

## 1. Connect to the HPC via SSH

1. Determine which cluster to use (examples):
   - Graham: `graham.computecanada.ca`
   - Cedar: `cedar.computecanada.ca`
   - Beluga: `beluga.computecanada.ca`
   - Niagara: `niagara.scinet.utoronto.ca`
   - ACENET: `login1.acenet.ca`

2. Open a terminal and connect via SSH:

   ```bash
   ssh username@graham.computecanada.ca
   ```

3. When prompted, confirm the host fingerprint and enter your password.

---

## 2. Create a Folder in Scratch

Your `$SCRATCH` directory is a temporary workspace for large data and computations. It is purged after 60 days of inactivity.

After logging in:

```bash
cd $SCRATCH
mkdir my_project
cd my_project
```

Confirm your path:

```bash
pwd
# Example output: /scratch/username/my_project
```

---

## 3. Install and Use Globus for File Transfers

Globus is a fast, reliable tool for large file transfers. It requires a small local agent called **Globus Connect Personal**.

### Install Globus Connect Personal

- **Linux:**  
  ```bash
  wget https://downloads.globus.org/globus-connect-personal/linux/stable/globusconnectpersonal-latest.tgz
  tar xzf globusconnectpersonal-latest.tgz
  cd globusconnectpersonal*
  ./globusconnectpersonal -setup
  ```

- **macOS:**  
  Download and install from: [https://www.globus.org/globus-connect-personal](https://www.globus.org/globus-connect-personal)

- **Windows:**  
  Download the installer from the same link and follow the setup wizard.

After installation, your local computer will appear as a **Globus endpoint**.

### Transfer Files

1. Visit [https://app.globus.org](https://app.globus.org) and log in using **Compute Canada credentials**.
2. In the web app, choose two endpoints:
   - **Source:** Your local computer or institutional storage.
   - **Destination:** Your HPC endpoint (for example, *Compute Canada Graham Scratch*).
3. Navigate to your target scratch folder (`/scratch/username/my_project`).
4. Select files and click **Start Transfer**.

Globus will handle transfers asynchronously and resume interrupted transfers automatically.

---

## 4. Submit Jobs to ACENET with SLURM

Job submissions use the SLURM scheduler. Create a batch file describing your job resources and commands.

### Example job script (`job.slurm`)

```bash
#!/bin/bash
#SBATCH --job-name=my_analysis
#SBATCH --account=def-yourprof
#SBATCH --time=2:00:00
#SBATCH --nodes=1
#SBATCH --ntasks=4
#SBATCH --mem=8G
#SBATCH --output=output_%j.log

module load python/3.11
source ~/myenv/bin/activate

python my_script.py
```

### Submit and Monitor Jobs

```bash
sbatch job.slurm        # Submit job
squeue -u username      # Check status
scancel job_id          # Cancel job
```

### View Results

After completion, check output logs:

```bash
less output_<jobid>.log
```

---

## 5. Useful Commands

```bash
module avail             # List available software modules
module load python/3.11  # Load a module
df -h $SCRATCH           # Check scratch usage
quota -s                 # Check your disk quota
```

---

## 6. References

- Alliance Docs: [https://docs.alliancecan.ca/wiki/Technical_documentation](https://docs.alliancecan.ca/wiki/Technical_documentation)
- ACENET Training: [https://www.ace-net.ca/training/](https://www.ace-net.ca/training/)
- Globus Setup: [https://www.globus.org/globus-connect-personal](https://www.globus.org/globus-connect-personal)