I have a two node setup in Azure and I am trying to get failover working when connecting with the C# driver. My nodes seem to be communicating fine when working with cqlsh and within OpsCenter.
var contact = "publicipforfirstnode";
_cluster = Cassandra.Cluster.Builder().AddContactPoint(contact).Build();
_session = _cluster.Connect("demo");
I initially connect with the public IP of the first node. This works fine. However in the configuration I use the internal network IPs assigned by my virtual network such as 10.1.0.4, 10.1.0.5, etc. I set them as the listen_address and broadcast_rpc_address for each node. Even though I use the internal IP in the configuration I can connect with the public IP just fine. I have a special firewall rule that allows me to connect from a certain machine on the public IP. However to avoid firewall rules for inner-node communication, I put the nodes on the same virtual network and no extra work is required.
This seems great until my first node goes down. It then tries the second node using the internal IP.
I get an error: All Hosts tried for query (Public IP of First Node), (Internal IP of Second Node)
But since I am connecting from a machine not in the virtual network it can't reach this internal ip. My application won't be in the internal network so this seems like an issue.
Not using internal ips forces me to setup authentication and/or special firewall rules I'd rather not have to do. Is there any way to force the c# driver to use public ips and allow the nodes to communicate on internal ips? Using internal ips seems to be the recommended best practice unless you have multiple regions.
The IP configured as broadcast_rpc_address in the cassandra.yaml file is used by the drivers to connect to them.
In your case, if you want to connect with the driver using the public ip addresses, you should set the broadcast_rpc_address as the public IP address.
You can enable tracing in the driver to see what is happening under the hood:
// Specify the minimum trace level you want to see
Cassandra.Diagnostics.CassandraTraceSwitch.Level = TraceLevel.Info;
// Add a standard .NET trace listener
Trace.Listeners.Add(new ConsoleTraceListener());