Cluster ports
When configuring an appliance cluster, we are required to specify the starting port number for a range of ports to be dedicated to the services that are provided by the cluster.
It is important to note these ports are for internal use only and are not used by the cluster for communication between nodes. All of the communication that takes place between nodes in
the cluster occurs over port 22. This means that if your nodes are separated by a firewall, you only
need to open up traffic on port 22 to allow the cluster services of the various nodes to communicate
with each other.
The following diagram illustrates the communication requirements of the various roles in the cluster.
To manually configure a DSC client on a node within the cluster, use the following addresses and ports: The following examples assume the first port is 2020.
| Node | Port | Example |
|---|---|---|
| Primary | first_port + 15 | 127.0.0.1 15 127.0.0.1:2035 |
| Secondary | first_port + 16 | 127.0.0.1 16 127.0.0.1:2036 |
| Tertiary | first_port + 17 | 127.0.0.1 17 127.0.0.1:2037 |
| Quarternary | first_port + 18 | 127.0.0.1 18 127.0.0.1:2038 |
Some additional settings are required to configure a DSC client on a node within the cluster. Set the priority for each distributed session cache server to 9 within the server stanza entry in the [dsess-cluster] stanza. Also set the load-balance stanza entry in the [dsess-cluster] stanza to no. The DSC does not support load balancing. Setting the load-balance configuration entry to no prevents connection attempts to servers for which the connection attempts will certainly fail.
Parent topic: Cluster configuration rules
Related reference