Tuning a Kafka Consumer

Your supermarket company has a consumer that logs data from the member_signups topic to System.out. This consumer acts as a utility to log the data for later auditing. However, there is a series of issues with this consumer that can be addressed through some minor alterations to its configuration. Examine the list of issues below and resolve them by implementing the necessary configuration changes in the consumer code.

You can find the consumer code on GitHub. Clone this project to the broker server. You can implement your configuration changes in the consumer class at src/main/java/com/linuxacademy/ccdak/consumer/MemberSignupsConsumer.java inside the project.

Make configuration changes to address the following issues:

• This consumer does not have a high need for real-time data since it is merely a logging utility that provides data for later analysis. Increase the minimum fetch size to 1 K (1024 bytes) to allow the consumer to fetch more data in a single request.
• Changes in consumer status (such as consumers joining or leaving the group) are not being detected quickly enough. Configure the consumer to send a heartbeat every two seconds (2000ms).

• Last week, someone tried to run this consumer against a new cluster. The consumer failed with the following error message:

  Exception in thread "main" org.apache.kafka.clients.consumer.NoOffsetForPartitionException: Undefined offset with no reset policy for partitions: [member_signups-0]

  Ensure the consumer has an offset reset policy that will allow the consumer to read from the beginning of the log when reading from a partition for the first time.

When you have implemented your changes, you can run the code with ./gradlew run to test it against the development broker.

If you get stuck, feel free to check out the solution video, or the detailed instructions under each objective. Good luck!