Danny Kay and Liz Bennett build an example of writing Kafka topic data to Elasticsearch:
The Elasticsearch sink connector helps you integrate Apache Kafka® and Elasticsearch with minimum effort. You can take data you’ve stored in Kafka and stream it into Elasticsearch to then be used for log analysis or full-text search. Alternatively, you can perform real-time analytics on this data or use it with other applications like Kibana.
For some background on what Elasticsearch is, you can read this blog post by Sarwar Bhuiyan. You can also learn more about Kafka Connect in this blog post by Tiffany Chang and in this presentation from Robin Moffatt.
This is a demo-heavy walkthrough, so check it out.