In this demo, a producer publishes two types of events—credit and debit—each to its own Kafka topic. A downstream processing pipeline (one or more Kafka consumers) subscribes to both topics, consumes incoming events, and groups them into separate batches (one batch for credit events, one for debit). Each batch is then processed independently—in this simple example, processing consists of persisting the events into a database.

docker run -p 9092:9092 apache/kafka:4.0.0

bin/kafka-topics.sh --create --topic bank_account_events --bootstrap-server localhost:9092

mix deps.get

mix ecto.create

mix ecto.migrate

--

iex -S mix

iex> KafkaXElixir.Services.BankAccount.EventProducer.send_many(5)

The pipeline will process the event, so you should see:

| 19:49:03.488 [info] Inserted 3 credits into the database