I stopped cassandra on a slave and then I've tried to start it again using:

ansible-playbook -i hosts site.yml --limit cislaves --tags cassandra

The command is executed correctly but cassandra did not start.

The script also intall the package cassandra21, but there is no need to do that as it is a
dependency of dsc21

It would also be nice to have these tasks in a separate folder like the Redis one