Storing data in Cassandra

According to the definition, Apache Cassandra is a free and open source, distributed NoSQL database management system designed to handle large amounts of data across many commodity servers, providing high availability with no single point of failure. This recipe shows how to connect Kafka and Cassandra.

Getting ready

This recipe uses a Kafka-Cassandra connector published on Maven Central by Tuplejump.

It can be defined as a dependency in the build file. For example, with SBT:

libraryDependencies += "com.tuplejump" %% "kafka-connect-cassandra" % "0.0.7"

How to do it...

Data can be fetched from Cassandra in two modes:

• Bulk
• Timestamp-based

The modes change automatically based on the query. For example, bulk:

SELECT * FROM userlog; 

For example, timestamp-based:

SELECT * FROM userlog WHERE ts > previousTime(); 
SELECT * FROM userlog WHERE ts = currentTime(); 
SELECT * FROM userlog WHERE ts >= previousTime() AND  ts <= currentTime() ;  

How it works...

Cassandra sink stores...