How do I connect to local cassandra db

Question

I have a cassandra db running locally. I can see it working in Ops Center. However, when I open dev center and try to connect I get a cryptic "unable to connect" error.

How can I get the exact name / connectionstring that I need to use to connect to this local cassandra db via dev center?

Answer 1

The hostname/IP to connect to is specified in the listen_address property of your cassandra.yaml.If you are connecting to Cassandra from your localhost only (a sandbox machine), then you can set the listen_address in your cassandra.yaml accordingly:

listen_address: localhost

When you start Cassandra, you should see lines similar to this either in STDOUT or in your system.log (timestamps removed for brevity):

Starting listening for CQL clients on localhost/127.0.0.1:9042...
Binding thrift service to localhost/127.0.0.1:9160
Listening for thrift clients...

These lines indicate which address you should be using to connect to your cluster. The first way to test your connection, is with clqsh. Note that cqlsh will connect to "localhost" by default. If you are connecting to a host/IP other than localhost, then you will need to specify it on the command line.

$ cqlsh
Connected to Test Cluster at localhost:9042.
[cqlsh 5.0.1 | Cassandra 2.1.0-rc5-SNAPSHOT | CQL spec 3.2.0 | Native protocol v3]
Use HELP for help.
cqlsh>

If this works, then you should also be able to connect (and test) from DataStax Dev Center (also on your local machine) by defining a connection to localhost, like this:

At this point, you should be able to connect via your application code (Java CQL3 driver shown):

cluster = Cluster.builder().addContactPoint("localhost").build();
Metadata metadata = cluster.Metadata;
Console.WriteLine("Connected to cluster: " + metadata.ClusterName.ToString());
Session session = cluster.connect();