Multi-Site Burst Renderer

A turnkey demo workflow for Parallel Works ACTIVATE that renders a Mandelbrot fractal in parallel across two compute sites, with tiles assembling in real-time in a live browser dashboard.

What It Does

1. Splits work across two ACTIVATE resources (e.g., an on-prem GPU server + a cloud Slurm cluster)
2. Renders Mandelbrot tiles in parallel — each site processes half the grid
3. Streams tiles via HTTP POST to a live dashboard running on the on-prem resource
4. Displays results in real-time through the ACTIVATE session proxy — tiles appear color-coded by source site

Architecture

              ACTIVATE Workflow
                    │
         ┌──────────┴──────────┐
         ▼                      ▼
  Cloud Cluster (Slurm)   On-Prem (SSH)
  renders tiles 0..N/2    renders tiles N/2..N
         │                      │
         └──── POST tiles ──────┘
                    │
              Dashboard Server
              (on-prem:PORT)
                    │
            ACTIVATE Session Proxy
                    │
              User's Browser

Quick Start

1. Start two ACTIVATE resources:
   • An on-prem/existing resource (e.g., a30gpuserver) — hosts the dashboard
   • A cloud cluster (e.g., googlerockyv3) — contributes rendering power
2. Run the workflow from the ACTIVATE UI or CLI:

   pw workflows run burst_renderer -i '{
     "onprem_resource": "pw://user/onprem_resource",
     "cloud_resource": "pw://user/cloud_cluster",
     "render_settings": {"grid_size": "8", "image_size": "256", "palette": "electric"}
   }'

3. Open the session link to watch tiles fill in live

Inputs

Input	Description	Options
On-Prem Resource	Always-on resource for dashboard + rendering	Any ACTIVATE resource
Cloud Resource	Cloud cluster for the other half of rendering	Any ACTIVATE cluster
Grid Size	Tiles per side (total = N x N)	4x4, 8x8, 16x16, 32x32
Tile Resolution	Pixel size of each tile	128px, 256px, 512px
Color Palette	Mandelbrot coloring scheme	Electric, Fire, Ocean, Cosmic

Dashboard Features

• Live canvas — tiles render and appear in real-time
• Site color-coding — blue borders = cloud, orange borders = on-prem
• Statistics — elapsed time, tiles/sec, avg render time, total tiles
• Throughput chart — tiles/sec over time by site
• Late-join support — opening the dashboard after rendering shows all completed tiles

File Structure

├── workflow.yaml              # ACTIVATE workflow definition
├── thumbnail.png              # Workflow thumbnail
├── README.md                  # This file
└── scripts/
    ├── setup.sh               # Verifies Python on remote hosts
    ├── start_dashboard.sh     # Launches FastAPI dashboard server
    ├── render_tiles.sh        # Renders tiles and POSTs to dashboard
    ├── dashboard.py           # FastAPI + WebSocket live dashboard
    ├── renderer.py            # Pure Python Mandelbrot renderer
    └── templates/
        └── index.html         # Dashboard UI (canvas + live stats)

Requirements

• Python 3.6+ on both compute resources
• Pillow (auto-installed; falls back to pure-Python PNG if unavailable)
• FastAPI + Uvicorn (auto-installed on the dashboard host)
• No GPU required — pure CPU rendering