Configuring gossip settings

Using the cassandra.yaml file to configure gossip.

When a node first starts up, it looks at its cassandra.yaml configuration file to determine the name of the Cassandra cluster it belongs to; which nodes (called seeds) to contact to obtain information about the other nodes in the cluster; and other parameters for determining port and range information.

The location of the cassandra.yaml file depends on the type of installation:
Cassandra package installations /etc/cassandra/cassandra.yaml
Cassandra tarball installations install_location/cassandra/conf/cassandra.yaml


In the cassandra.yaml file, set the following parameters:
cluster_name Name of the cluster that this node is joining. Must be the same for every node in the cluster.
listen_address The IP address or hostname that Cassandra binds to for connecting this node to other nodes.
listen_interface Use this option instead of listen_address to specify the network interface by name, rather than address/hostname
(Optional) broadcast_address The "public" IP address this node uses to broadcast to other nodes outside the network or across regions in multiple-region EC2 deployments. If this property is commented out, the node uses the same IP address or hostname as listen_address. A node does not need a separate broadcast_address in a single-node or single-datacenter installation, or in an EC2-based network that supports automatic switching between private and public communication. It is necessary to set a separate listen_address and broadcast_address on a node with multiple physical network interfaces or other topologies where not all nodes have access to other nodes by their private IP addresses. For specific configurations, see the instructions for listen_address. The default is the listen_address.
seed_provider A -seeds list is comma-delimited list of hosts (IP addresses) that gossip uses to learn the topology of the ring. Every node should have the same list of seeds.
Attention: In multiple data-center clusters, include at least one node from each datacenter (replication group) in the seed list. Designating more than a single seed node per datacenter is recommended for fault tolerance. Otherwise, gossip has to communicate with another datacenter when bootstrapping a node.

Making every node a seed node is not recommended because of increased maintenance and reduced gossip performance. Gossip optimization is not critical, but it is recommended to use a small seed list (approximately three nodes per datacenter).

storage_port The inter-node communication port (default is 7000). Must be the same for every node in the cluster.
initial_token For legacy clusters. Set this property for single-node-per-token architecture, in which a node owns exactly one contiguous range in the ring space.
num_tokens For new clusters, the number of tokens randomly assigned to this node in a cluster that uses virtual nodes (vnodes).