How to set JGroups ports for protocols in EAP 7.1 ?

Solution Verified - Updated -

Environment

  • Red Hat JBoss Enterprise Application Platform (EAP)
    • 7.1+

Issue

  • I need to configure IPTABLES or a Firewall for an EAP cluster, what are the required JGroups ports ?
  • I see a WARN message if a ha profile is started in EAP 7.1, if the JGroups subsystem is configured like we have in EAP6 as below :
WFLYCTL0028: Attribute 'socket-binding' in the resource at address '/subsystem=jgroups/stack=udp/protocol=FD_SOCK' is deprecated, and may be removed in future version. See the attribute description in the output of the read-resource-description operation to learn more about the deprecation.
  • Legacy versions configure the FD_SOCK protocol ports by a socket-binding like followed, but this is not working with EAP 7.1
  <protocol type="FD_SOCK" socket-binding="jgroups-udp-fd"/>
  ...
   <socket-binding-group name="standard-sockets" default-interface="public" port-offset="${jboss.socket.binding.port-offset:0}">
       ...
        <socket-binding name="jgroups-udp-fd" interface="private" port="54200"/>

Resolution

  • All protocols will bind to the same interface as the transport. Ports are selected randomly.
  • To have fixed ports properties can be set to use a specific range as below :
<protocol type="FD_SOCK">
  <property name="client_bind_port">50100</property>
  <property name="start_port">50000</property>
  <property name="port_range">0</property>
</protocol>
  • That means the above config uses 50100 to listen to socket connections from remote nodes and 50000 to establish connections to remote nodes.
  • If you have multiple instances at the same machine you need to have a port_range > 0 to allow it, the range is 0 by default.
  • Note that client_bind_port is rarely configured. It is only needed if a firewall filters based on client IP, which is not a widely used firewall configuration.

Root Cause

  • There are no longer socket-bindings needed for the FD_SOCK protocol. The ports are selected randomly and the former socket-binding was only used to choose the interface.

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