Apache Cassandra was written in Java, and therefore requires a JVM to run. Make sure to download a Java Runtime Environment (JRE) or Java Development Kit (JDK) to include as a part of your Cassandra installation. Unless otherwise noted, the latest patch of version 8 of the Oracle JDK or OpenJDK should be used.
At the time of writing, Apache Cassandra is not currently compatible with Java 9 or higher.
Adjustments to the JVM settings used by Cassandra can be made in the jvm.options configuration file. Many of those settings deal with the configuration and tuning of the garbage collector.
