Multiple instances of Cassandra and/or Doradus can be used in the same cluster. As described in the section Deployment Guidelines, a recommended practice is to deploy an instance of both Doradus and Cassandra on each node. Then, each Doradus instance should be configured to contact all Cassandra nodes. This provides load balancing and fault tolerance in case a Cassandra node fails.The Cassandra instance(s) to which each Doradus instance connects is defined in the dbhost parameter in its doradus.yaml file. This parameter should be set to a comma-separated list of host names or (preferably) IP addresses of Cassandra instance hosts. For example: