README.md

KPI Dashboard

A fast, simple, streaming dashboard for KPIs.

For this codebase we imagine we have a business running, selling things, and recording those sales in a purchases topic. A dummy process runs in the background simulating those sales.

From there, we build out a ksqlDB summary table, a websocket server, and a React frontend. As new purchases come in, ksqlDB updates the summary table, which is streamed to the webserver, which sends the new record out to all connected clients for display.

Presentation

You can watch a complete walkthrough of this code being built up from scratch here:

Code Layout

(This code assumes you are running Kafka & ksqlDB locally. You will need to modify configuration files if that's not the case.)

In brief

The most interesting files in here are:

• The table: dashboard_table.sql
• The webserver: pythonserver/server.py
• The frontend: client/src/App.js

The "Business" Simulator

setup.sql creates the purchases table. Run it with ksql -f setup.sql.

Then run the process that generates dummy purchases:

cd javaserver
gradle runGenerator

ksqlDB

dashboard_table.sql is the code to create the summary table. Run it with ksql -f dashboard_table.sql, or type it by hand - it's short and informative.

Websocket Server

The server is written in Python. Run it with:

cd pythonserver
virtualenv env
source env/bin/activate

pip install confluent_kafka websockets simplejson
./server.py

If you have ws installed you can easily test the server with ws ws://localhost:8080.

React frontend

The frontend is a simple React app. Run it with:

cd client
yarn start