Example Product/User Analytics

by heroku-examples

GitHub Readme.md

Example Product/User Analytics System Using Apache Kafka, AWS Redshift, and Metabase

This app also includes Heroku Connect Data Demo

This is an example of a system that captures a large stream of product usage data, or events, and provides both real-time data visualization and SQL-based data analytics. The stream of events is captured by Apache Kafka and made available to other downstream consumers. In this example, there are two downstream consumers of the data. The data flowing through Kafka can be viewed in near real-time using a web-based data visualization app. The other consumer stores all the data in AWS Redshift, a relational database that Amazon describes as "a fast, scalable data warehouse." Then we can query and visualize the data in Redshift from a SQL-compliant analytics tool. This example uses Metabase deployed to Heroku. Metabase is an open-source analytics tool used by many organizations, large and small.

This entire system can be deployed in 15 minutes -- most of that time spent waiting for Heroku and AWS to provision services -- and it requires very little ongoing operational maintenance.

Here's an overview of how the system works.


This project includes 3 apps:

  1. A data producer called generate_data. Data is simulated in this example, but this could be replaced with almost anything that produces data: a marketing website, a SaaS product, a point-of-sale device, a kiosk, internet-connected thermostat or car. And more than one data producer can be added.
  2. A real-time data visualizer called viz, which shows relative volume of different categories of data being written into Kafka.
  3. And a Kafka-to-Redshift writer called reshift_batch, which simply reads data from Kafka and writes it to Redshift.

They all share data using Apache Kafka on Heroku.

You can optionally deploy Metabase to Heroku to query Redshift. Check out Metabase's Heroku Deploy Button.



  • An AWS Redshift cluster. Check out this Terraform script for an easy way to create a Redshift cluster along with a Heroku Private Space and a private peering connection between the Heroku Private Space and the Redshift's AWS VPC. Not free! This will incur cost on AWS and Heroku.
  • Node.js

Deploy to Heroku

git clone git@github.com:heroku-examples/kafka-stream-viz.git
cd kafka-stream-viz
heroku create
heroku addons:create heroku-kafka:basic-0
heroku kafka:topics:create ecommerce-logs
heroku kafka:consumer-groups:create redshift-batch
heroku config:set KAFKA_TOPIC=ecommerce-logs
heroku config:set KAFKA_CMD_TOPIC=audience-cmds
heroku config:set KAFKA_WEIGHT_TOPIC=weight-updates
heroku config:set KAFKA_QUEUE_TOPIC=queue-length
heroku config:set KAFKA_QUEUE_WORKER=queue-worker
heroku config:set KAFKA_CONSUMER_GROUP=redshift-batch
heroku config:set FIXTURE_DATA_S3='s3://aws-heroku-integration-demo/fixture.csv'
git push heroku master

Alternatively, you can use the Heroku Deploy button:


And then create the necessary Kafka topic and consumer group:

heroku kafka:topics:create ecommerce-logs #this can also be created at https://data.heroku.com/
heroku kafka:topics:create audience-cmds #this can also be created at https://data.heroku.com/
heroku kafka:topics:create weight-updates #this can also be created at https://data.heroku.com/
heroku kafka:topics:create queue-length #this can also be created at https://data.heroku.com/
heroku kafka:consumer-groups:create redshift-batch

Optionally, you can deploy Metabase to Heroku and use SQL to query and visualize data in Redshift. Use Metabase's Heroku Deploy button. Once deployed, you'll need to configure Metabase with the Redshift cluster URL, database name, username, and password.

Deploy Locally

git clone git@github.com:heroku-examples/kafka-stream-viz.git
npm i


The following environment variables must be defined. If you used the Heroku deploy instructions above, all of the variables are already defined except for DATABASE_URL.

  • DATABASE_URL: Connection string to an AWS Redshift cluster
  • FIXTURE_DATA_S3: S3 path to CSV of fixture data to load into Redshift before starting data stream through Kafka (e.g. s3://aws-heroku-integration-demo/fixture.csv)
  • KAFKA_URL: Comma-separated list of Apache Kafka broker URLs
  • KAFKA_CLIENT_CERT: Contents of the client certificate (in PEM format) to authenticate clients against the broker
  • KAFKA_CLIENT_CERT_KEY: Contents of the client certificate key (in PEM format) to authenticate clients against the broker
  • KAFKA_TOPIC: Kafka topic the system will produce to and consume from
  • KAFKA_CMD_TOPIC: Kafka topic the system will read audience cmds from
  • KAFKA_WEIGHT_TOPIC: Kafka topic the system will produce category weight updates to
  • KAFKA_QUEUE_TOPIC: Kafka topic the system will produce queue length updates to
  • KAFKA_QUEUE_WORKER: Kafka topic the system will produce queue worker processing updates to
  • KAFKA_CONSUMER_GROUP: Kafka consumer group name that is used by redshift_batch process type to write to Redshift.
  • KAFKA_PREFIX: (optional) This is only used by Heroku's multi-tenant Apache Kafka plans (i.e. basic plans)

Then in each of the generate_data, viz, and redshift_batch directories, run npm start.

Open the URL in the startup output of the viz app. It will likely be http://localhost:3000.

Heroku Connect Data Demo

This is an addition to the project above and not required to run

This is an example project of showing how Salesforce and Heroku Postgres can be synced using Heroku Connect.


  1. Create a Salesforce DevHub Account - https://developer.salesforce.com
  2. Add a Heroku Connect addon to the application
  3. Connect the Heroku Connect addon to your Salesforce DevHub organization and to the PostgreSQL Database
  4. Go to External Objects tab and enable external objects, select orders and copy the URL, Username, and password from the credentials section

Deploy Salesforce Application

  1. Deploy the Supply Demand app to Salesforce by running
cd sfdx/order-fulfillment
sfdx force:auth:web:login -a DevHub # This will open a browser for you to login to Salesforce
sfdx force:source:push
sfdx force:org:open
  1. Configure Heroku Connect External Data Source
  • On Salesforce go to Setup > Integrations > External Data Sources click on edit on the Heroku Connect data source.
  • Replace the URL with the one from Step 4 on the prerequisites section.
  • Go to the Authentication section and select Password Authentication on the Authentication Protocol dropdown
  • Fill Username and Password from Step 4 on the prerequisites section.
  • Click on Save
  1. Go to the app menu and open Supply Demand and voila!

Data Demo Structure

This project uses viz for the web interface to show the chart that represents supply and demand using fulfillment order and purchase order of products in specific categories in Salesforce. This project also uses a generate_orders which is a worker automatically creating orders periodically.

generate_orders creates orders and the viz shows the demand chart.

This project add new routes /connect and /ordercontrol to the viz app. /connect show the demand chart and /ordercontrol gives you UI to control the generate_orders.

The detail of generate_orders can be found here.

Deploy Data Demo

Data Demo Prerequisites

This project is an addition to the existing project above so make sure you have everything running first. Following items are needed:

  • Salesforce account
  • Postgres add-on
  • Redis add-on
  • Heroku Connect

You can install Posgres and Redis add-ons by runnning these:

heroku addons:create heroku-postgresql:<PLAN_NAME>
heroku addons:create heroku-redis:<PLAN_NAME>

Conneting your Heroku Postgres and Salesforce, please check this instruction.

Deploy Data Demo to Heroku

This app is automatically deployed together with the main project. However, it requires additional environment variables and those add-ons above.

Environment Variables

These variables need to be set to run the app. Most of them are from Salesforce.

New Routes

You can access these locally and from the Heroku app.

  • /connect This route shows the chart
  • /ordercontrol please check the detail from here.

Heroku Connect Demo Configuration

There are two config folders for the heroku connect demo. It's using https://github.com/lorenwest/node-config


This config is for the visual part of the chart

  • MAX_SNAPSHOTS_PAST_MINUTES This variable defines how far back the user can request the list of snapshots of each miniutes.

  • DEFAULT_DATA_PERIOD When this service pull the data from the database, it looks up the data in this period. If it's set to 1 week then the data is calculated from a week ago to now.

  • FULFILLMENT_ORDER_TYPE The name of the fulfilment order type

  • PURCHASE_ORDER_TYPE The name of the purchase order type

  • REDIS_CHANNEL The name of the redis channel

  • CATEGORY_LIST The list of the category to use

  • UPDATE_INTERVAL This variable defines how often this service pulls the new data from the database

chrat.js Config

Configuration for the chrat.js

  • CHART_VISIBLE_MINS This variable defines the visible period of the chart. If it's set to 2, then the chart shows the past 2 mins.

  • CHART_COLOR_LIST This list defines the color of each lines in the chart.

  • CHART_REFRESH_DURATION This defines the how often the chart updates with the new data

  • CHART_DELAY This defines the offset period before the new data gets revealed. For example, if it's set to 15000, chart is always showing the data from 15 seconds ago

  • CHART_LINE_THICKNESS This defines the thickness of each lines in the chart


It's explained here.