MSK Data Generator is a translation of the awesome Voluble Apache Kafka data generator from Clojure to Java. (Link in Resources Section below)

The killer feature is being able to generate events which reference other generated events. (AKA: cross-reference, reference-able, joinable, etc.)

For example, we can generate one stream of Order events containing a customer_id (as well as price, sku, quantity, etc.) and at same time, we can generate a different stream of Customer events containing a customer_id (as well as first name, last name, location, etc.) The dynamically generated Customer event customer_id can reference the Order event customer_id.

Multiple streams of "joinable" data is especially useful when building stream processor applications (in Kinesis Data Analytics for Apache Flink or Kinesis Data Analytics Studio for example) which perform joins.

For an example, see AWS Big Data Blog Query your Amazon MSK topics interactively using Amazon Kinesis Data Analytics Studio

By translating to Java, the hope is we open up the potential of wider community collaboration. (Nothing against Clojure mind you! It's just more folks know Java.)

This project can likely be used outside of Amazon MSK, but to start at least, the focus will be making this generator easy to use with Amazon MSK.

MSK Data Generator is deployed and configured as a Kafka Connect Source, so basic knowledge of Kafka Connect will be helpful.

Like many dynamic data generation projects, the key component is the use of Java Faker library. Knowing more about Java Faker capabilities and options will be helpful.
See link in Resources section below.

MSK Data Generator can be deployed in a variety of ways including:

• Deploying in a container running in Elastic Container Service

• Deploying as a Kafka Connect source connector in MSK Connect

There are 5 essential constructs to understand when customizing key-value data generation:

1. Directives genk, genkp, genv, and genvp

2. Generators with or matching

3. Attribute the name of the field to generate data

4. Qualifiers sometimes

5. Expressions based on Java faker

For example, consider the configuration of the following:

"genkp.customer.with": "#{Internet.uuid}",
"genv.customer.name.with": "#{Name.full_name}",
"genv.customer.gender.with": "#{Demographic.sex}",
"genv.customer.favorite_beer.with": "#{Beer.name}",
"genv.customer.state.with": "#{Address.state}",

"genkp.order.with": "#{Internet.uuid}",
"genv.order.product_id.with": "#{number.number_between '101','109'}",
"genv.order.quantity.with": "#{number.number_between '1','5'}",
"genv.order.customer_id.matching": "customer.key"

This config will generate data to the customer and customer topics and assumes the MSK cluster has been configured to allow auto topic creation OR the customer and order topics have already been created.

For example, the above configuration will create 2 events with every iteration similar to the following:

customer event with a key of 0c88cbb7-eb4a-44f0-83aa-00957761b3b6 (because Internet.uuid for random string from Java Faker) and JSON payload of

{
   "favorite_beer": "Weihenstephaner Hefeweissbier",
   "gender": "Male",
   "name": "Miss Gilbert Luettgen",
   "state": "Oregon"
}

order event with a random string key of dc236186-9037-45a0-8b91-a3c2b50f0582 (again, because of Internet.uuid) and a JSON payload of

{
   "quantity": "4",
   "product_id": "132",
   "customer_id": "0c88cbb7-eb4a-44f0-83aa-00957761b3b6"
}

Notice how the order event customer_id value references the previously generated customer key field? (Hint: with this kind of data generation, we can test our join code!)

This also highlights the differences between with and matching in configuration.

In this example, with is utilizing and methods available from Java Faker see API docs and then compare the class methods with configuration above such as Name.full_name, Beer.name, etc.

With this example above and the 5 previously mentioned essential constructs in mind, the sequence is:

directive.topic.attribute-or-qualifier.generator: expression

For further information on data generation configuration options, check both the Voluble README as well as some of the examples in this repo

• Voluble (basis for this project) https://github.com/MichaelDrogalis/voluble

• Java Faker https://github.com/DiUS/java-faker

• Java Faker API docs https://dius.github.io/java-faker/apidocs/