/etc/yum.conf

[main]
cachedir=/var/cache/yum
debuglevel=2
logfile=/var/log/yum.log
pkgpolicy=newest
distroverpkg=fedora-release
tolerant=1
exactarch=1

[base]
name=Fedora Core $releasever - $basearch - Base
#baseurl=http://fedora.redhat.com/release...

openjdk-8-jdk

$ sudo apt-get install software-properties-common
$ sudo add-apt-repository ppa:openjdk-r/ppa

$ update-alternatives --set java /usr/java/jdk1.8.0_60/bin/java
# update-alternatives --all

cassandra

$ sudo gpg --keyserver pgp.mit.ed...