I'm just getting started with Cassandra and had a few questions. I'm going to be deploying a 4 node cluster on AWS as per the DataStax documentation (http://www.datastax.com/docs/datastax_enterprise3.1/install/install_dse_ami).
Once I have this 4 node cluster up and running, i'll be creating a simple LAMP server which will (hopefully) do the querying to the cluster. I'll be using Cassandra-PDO for the communication (http://code.google.com/a/apache-extras.org/p/cassandra-pdo/). This totals 5 servers in the end.
192.168.0.1 - Cassandra1
192.168.0.2 - Cassandra2
192.168.0.3 - Cassandra3
192.168.0.4 - Cassandra4
192.168.0.5 - LAMP Stack
How do I balance all my requests from the LAMP server to my Cassandra cluster? In the CPDO example, they mention the following:
$dsn = "cassandra:host=192.168.0.1;port=9160,host=192.168.0.2,port=9160";
However, what do I do if I don't know what the IP's are? What happens if I add new nodes? Old nodes fail, etc etc? Do you have to somehow load balance the requests yourself?
Any advice on the above would be hugely appreciated!