Database Reference
In-Depth Information
cassandra> connect 192.168.1.5/9160
Connected to: "TDG Cluster" on 192.168.1.5/9160
cassandra> set Keyspace1.Standard2['mykey']['col0']='value0'
Value inserted.
Now let's open a second CLI client and read that value from the 1.7 node:
cassandra> connect 192.168.1.7/9160
Connected to: "TDG Cluster" on 192.168.1.7/9160
cassandra> get Keyspace1.Standard2['mykey']['col0']
=> (column=col0, value=value0, timestamp=1278878907805000
You can repeat these steps to add additional nodes to your cluster.
If there's something wrong with one of the nodes in your cluster (perhaps it's offline, but Cas-
sandra is not sure), you may see a question mark when you run node tool:
$ bin/nodetool -h 192.168.1.5 ring
Address Status Load Range Ring
112711146095673746066359353163476425700
192.168.1.5 Up 459.26 MB 27647275353297313886547808446514704912 |<--|
192.168.1.7 ?
229.53 MB 112711146095673746066359353163476425700 |-->|
Multiple Seed Nodes
Cassandra allows you to specify multiple seed nodes. A seed node is used as a contact point for
other nodes, so Cassandra can learn the topology of the cluster, that is, what hosts have what
ranges.
By default, the configuration file will have only a single
seed
entry:
seeds:
- 127.0.0.1
To add more seed nodes to your ring, just add another seed element. We can set two servers to
be seeds just by indicating the IP address or hostname of this node and then adding our second
instance:
seeds:
- 192.168.1.5
- 192.168.1.7
