1bln Cell Spreadsheet Techdemo

This is a tech demo showing incremental computation for a simple, spreadsheet-like application. The application uses feldera as the DBMS/incremental compute engine, axum as the backend and egui as the frontend.

The project is split into three components from the root directory:

• The feldera directory contains the feldera pipeline (written in Feldera/SQL and some Rust UDF code).
• The server directory contains the backend application (written in Rust using the axum webserver).
• The client directory contains the frontend application (written in Rust using the egui UI library).

Local Installation

You'll need a working rust installation to run the project locally.

Feldera

Install a feldera instance, or alternatively use the feldera instance running on https://try.feldera.com. Also, you'll need to install Feldera's CLI tool fda.

Set the FELDERA_API_KEY and FELDERA_HOST environment variables to access the right feldera instance. Finally, execute the deploy.sh script in the feldera directory to deploy the pipeline:

export FELDERA_API_KEY=apikey:...
export FELDERA_HOST=https://try.feldera.com
cd feldera && bash deploy.sh

Server

Run the server application with cargo:

cd server
cargo run

Now the backend should be running on http://localhost:3000. The backend will connect to your feldera instance to fetch the data. The server uses the FELDERA_API_KEY and FELDERA_HOST environment variables set earlier, make sure they're still set correctly.

Client

Run the client application with trunk:

cd client
API_HOST=http://localhost:3000 trunk serve --port 7777

Now the frontend should be running on http://localhost:7777. The frontend will connect to the backend to fetch the data. The API_HOST environment variable is set to point to the backend running on http://localhost:3000.

Automated Deployment with Github Actions

The project is set up to deploy the server backend to fly.io and the client application is published using github pages.

Feldera

Make sure to set the FELDERA_API_KEY and FELDERA_HOST secrets in the github repository settings.

Server

Get a fly.io account and install the fly CLI tool.

Next make sure to set the FELDERA_API_KEY and FELDERA_HOST secrets also in your fly.io application.

cd server
fly login
fly secrets set FELDERA_HOST=https://try.feldera.com
fly secrets set FELDERA_API_KEY=apikey:...

Finally, you'll need to get an API token from fly.io and set it as a secret named FLY_API_TOKEN in the github repository settings.

Client

Make sure to set the API_HOST secret in the github repository settings to point to your fly.io application URL. Enable github pages, set the source to Github Actions. Then adjust the public_url env variable in the client.yml github action file to point to your github pages URL.