Configuring Peer Communication

By default vFabric GemFire uses TCP for communication between members of a single distributed system. You can modify this at the member and region levels.

Before you begin, you should have a basic understanding of member discovery. You should also have already determined the address and port settings for multicasting, including any bind addresses. See Topology and Communication General Concepts.

See and (vFabric GemFire Property Files) and cache.xml (Declarative Cache Configuration File).
  1. Configure general messaging to use TCP or UDP unicast.
    TCP is the default protocol for communication. To use it, just make sure you do not have it disabled in Either have no entry for disable-tcp, or have this entry:
    To use UDP unicast for general messaging, add this entry to

    The disable-tcp setting has no effect on the use of TCP locators.

  2. Configure any regions you want to distribute using UDP multicast.
    1. Configure UDP multicast for region messaging, set non-default multicast address and port selections in
    2. In cache.xml, enable multicast for each region that needs multicast messaging:
      <region-attributes multicast-enabled="true"/> 
      Note: Improperly configured multicast can affect production systems. If you intend to use multicast on a shared network, work with your network administrator and system administrator from the planning stage of the project. In addition, you may need to address interrelated setup and tuning issues at the GemFire, operating system, and network level.

Once your members establish their connections to each other, they will send distributed data and messages according to your configuration.