Kafka

You are viewing the English version of this page because it has not yet been fully translated. Interested in helping out? See Contributing.

This is used as a message queue service to connect the checkout service with the accounting and fraud detection services.

Kafka service source

Configuration

VariableDefaultDescription
KAFKA_TOPICordersTopic that checkout produces order messages to, and that accounting and fraud detection consume from.

All three services read the same variable, so change it in .env (or .env.override) rather than on an individual service, otherwise the producer and consumers end up on different topics.

Auto-instrumentation

This service relies on the OpenTelemetry Java agent and the built in JMX Metric Insight Module to capture Kafka broker metrics and send them off to the collector via OTLP.

The agent is passed into the process using the -javaagent command line argument. Command line arguments are added through the KAFKA_OPTS in the Dockerfile.

ENV KAFKA_OPTS="-javaagent:/tmp/opentelemetry-javaagent.jar -Dotel.jmx.target.system=kafka-broker"