Apache Cassandra
Install Apache Cassandra on Ubuntu 16.04
This adds repo for the stable release of 3.11.x.
$ echo "deb http://www.apache.org/dist/cassandra/debian 311x main" | sudo tee -a /etc/apt/sources.list.d/cassandra.sources.list
Add the repository keys.
$ curl https://www.apache.org/dist/cassandra/KEYS | sudo apt-key add -
$ sudo apt-key adv --keyserver pool.sks-keyservers.net --recv-key A278B781FE4B2BDA