Functions are lightweight compute processes that enable you to process each message received on a topic. You can apply custom logic to that message, transforming or enriching it, and then output it to a different topic. Functions include durable state storage, so you can maintain state, for example a counter, related to the function.
Functions run inside the Kafkaesque Pulsar cluster and are therefore severless. You write the code for your function in Java or Python then upload the code. It will be automatically run for each message published to the specified input topic.
Functions are implemented using Apache Pulsar functions. See Pulsar Functions overview for more information about Apache Pulsar functions.
Support for Go functions is coming soon.