20.13.2. Broadcast Groups

Connectors are used on the client to define how and in what ways it connects to the server. Servers use broadcast groups to broadcast connectors over the network. The broadcast group takes a set of connector pairs and broadcasts them on the network. Each connector pair contains connection settings for a live and backup server.
You can define broadcast groups in broadcast-groups element of server configuration files (standalone.xml and domain.xml). A single HornetQ server can have many broadcast groups. You can define either a User Datagram Protocol (UDP) or a JGroup broadcast group.

20.13.2.1. User Datagram Protocol (UDP) Broadcast Group

The example shown below defines a UDP broadcast group:
<broadcast-groups>
   <broadcast-group name="my-broadcast-group">
      <local-bind-address>172.16.9.3</local-bind-address>
      <local-bind-port>5432</local-bind-port>
      <group-address>231.7.7.7</group-address>
      <group-port>9876</group-port>
      <broadcast-period>2000</broadcast-period>
      <connector-ref>netty</connector-ref>
  </broadcast-group>
</broadcast-groups>

Note

In the configuration example shown above, the attributes "local-bind-address", "local-bind-port", "group-address" and "group-port" are deprecated. Instead of these attributes you can choose to use the attribute "socket-binding".
The example shown below defines a UDP broadcast group replacing all the deprecated attributes with the attribute "socket-binding":
<broadcast-groups>
   <broadcast-group name="my-broadcast-group">
      <socket-binding>messaging-group</socket-binding>
      <broadcast-period>2000</broadcast-period>
      <connector-ref>netty</connector-ref>
   </broadcast-group>
</broadcast-groups>
The table shown below describes all the important parameters used in the above examples and in general to define a UDP broadcast group:

Table 20.11. UDP Broadcast Group Parameters

Attribute Description
name attribute
Denotes the name of each broadcast group in a server. Each broadcast group must have a unique name.
local-bind-address
[Deprecated] This is a UDP specific attribute and specifies the local bind address which the datagram packet binds to. You must set this property to define the interface which you wish to use for your broadcasts. If this property is not specified then the socket binds to a wildcard address (a random kernel generated address).
local-bind-port
[Deprecated] This is a UDP specific attribute and is used to specify a local port which the datagram socket binds to. A default value of "-1" specifies an anonymous port to be used.
group-address
[Deprecated] This is a multicast address specific to UDP where messages are broadcast. This IP address has a range of 224.0.0.0 to 239.255.255.255, inclusive. The IP address 224.0.0 is reserved and can not be used.
group-port
[Deprecated] This denotes the UDP port number for broadcasting.
socket-binding
This denotes the broadcast group socket binding
broadcast-period
This parameter specifies the time between two broadcasts (milliseconds). It is optional.
connector-ref
This refers to the connector which will be broadcasted.