Add Apache Druid to the cluster

You use Apache Ambari to add Apache Druid (incubating) to your cluster.

1. On the Ambari host, download the database connector that matches your database.
   For MySQL, on Centos 7.4 for example:

   yum install mysql-connector-java*

   The database is installed in /usr/share/java.
2. On the Ambari server node, run the command to set up the connector, which includes the path to the downloaded JAR. For MySQL, on Centos 7.4 for example:
   ambari-server setup --jdbc-db=mysql --jdbc-driver=/usr/share/java/mysql-connector-java.jar
3. Start Ambari, and in Ambari select Services > Add Service.
4. Select Druid, and click Next.
5. In Assign Masters, typically you can accept the defaults to put the Broker, Coordinator, Overload, and Router components on the same master node, and click Next.
6. In Assign Slaves and Clients, putting Druid Historical and Druid MiddleManager on the same nodes and running these co-located components on additional nodes is recommended.