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Configuring the cluster discovery protocol

You can configure the Cluster Manager to use the UDP multicast, UDP broadcast, UDP unicast, or TCP protocols.

The protocol defines how heartbeats are received from nodes in the cluster. You specify the protocol in the environment file.


If the Cluster Manager protocol is not specified, then multicast applies.

To specify the cluster discovery protocol:

  1. In NexJ Studio navigate to the Deployment layer.
  2. In the Environments tab, open the environment file for your NexJ application.
  3. In the Source tab, in the <Environment> tag, add the following attributes:
    Specifies the protocol type. The type can be multicast, broadcast, unicast, or tcp.
    Specifies the port on which the Cluster Manager listens for and sends heartbeats. For non-TCP, the default value used is <ObjectQueue messagePort>. For the TCP protocol, the default value is 1112.
    Sends your IP address to a range of broadcast IP addresses simultaneously and receives on your own IP address. If not specified, the default value is


    clusterBroadcastAddress applies only to the UDP broadcast protocol.

    Is a value chosen from a reserved range of IP addresses that sends and receives to multicast IP addresses. If not specified, the default value is


    clusterMulticastGroup applies only to the UDP multicast protocol.

    The following example shows settings for a unicast protocol:
    clusterDiscoveryProtocol="<unicast>" clusterDiscoveryPort="<1212>"

  4. [Optional] If you use the UDP unicast or TCP protocol, nodes in the cluster are auto-discovered by each node. If auto discovery is not enabled, you must specify the full list of nodes in the nodes attribute in the environment file. Separate port offsets for IP addresses with a plus sign (+), as shown in the following example:

  5. Click Save

    in the toolbar to save the changes to the environment.

You have configured the protocol for the Cluster Manager.

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