The Cluster Properties page displays a list of the properties that are set for the selected clusters. These properties add optional configuration information about the cluster.
The Cluster Name field is a read-only field that displays the name of the selected cluster.
For each property, the following information is displayed:
The name of the property.
The value that of the property that is set for the selected instance.
A textual description that provides more information about the property.
The Additional Properties table also contains the following options.
Button to add a property. Clicking this button adds a row to the Additional Properties table.
Button to delete one or more selected properties. Any property that is deleted reverts to its default value or, if no default value is set, is undefined.
GlassFish Server defines the following cluster properties:
GMS_LISTENER_PORT
The port number of the port on which the cluster listens for messages from the Group Management Service (GMS).
The default value is ${GMS_LISTENER_PORT-
cluster-name}
. In most situations, this default value should suffice.
However, if GMS is not using multicast for broadcasting messages, this property must specify a port number that is valid for all GlassFish Server instances in the cluster. To use the default value to meet this requirement, use a system property to set the port number individually for each instance.
For example, use the Cluster System Properties page to create the system property GMS_LISTENER_PORT-
cluster-name. Then, for each instance in the cluster, set the GMS_LISTENER_PORT-
cluster-name system property to the port number on which the instance listens for messages from GMS. The default value of the GMS_LISTENER_PORT
property for the cluster references this system property.
GMS_LOOPBACK
Specifies whether an instance may receive from itself application-level messages that the instance broadcasts to the cluster.
Possible values are as follows:
false
The instance may not receive messages from itself (default).
true
The instance may receive messages from itself. Use this setting for testing an instance when the instance is the only instance in a cluster.
GMS_MULTICAST_TIME_TO_LIVE
The maximum number of iterations or transmissions that a multicast message for the following types of events can experience before the message is discarded:
Group discovery
Member heartbeats
Membership changes
To match the configuration of the network on which the DAS and clustered instances are deployed, set this value as low as possible. To determine the lowest possible value for your system, use the validate-multicast
(1) subcommand.
A value of 0 ensures that multicast messages never leave the host from which they are broadcast.
A value of 1 might prevent the broadcast of messages between hosts on same subnet that are connected by a switch or a router.
The default is 4, which ensures that messages are successfully broadcast to all cluster members in networks where hosts are connected by switches or routers.
GMS_DISCOVERY_URI_LIST
The locations of the GlassFish Server instances to which GMS is to send group events. This property is required only if GMS is not using multicast for broadcasting messages.
Valid values for this property are as follows:
A comma-separated list of uniform resource identifiers (URIs). Each URI must locate a GlassFish Server instance. This format is required if multiple GlassFish Server instances are running on the same host.
The format of each URI in the list is as follows:
scheme://
host-name-or -IP-address:
port
scheme is the URI scheme, which is tcp
.
host-name-or -IP-address is the host name or IP address of the host on which the instance is running.
port is the port number of the port on which the instance listens for messages from GMS. The system property GMS_LISTENER_PORT-
clustername must be set for the instance. For information about how to set this system property for an instance, see Locating GlassFish Server Instances When Multicast Is Disabled, in Oracle GlassFish Server High Availability Administration Guide.
A comma-separated list of IP addresses or host names. The list can contain a mixture of IP addresses and host names. This format can be used only if one clustered instance is running on each host. The value of the GMS_LISTENER_PORT
property must be unique for each cluster in a domain.
The keyword generate
. This format can be used only if one instance in a cluster is running on each host. Multiple instances on the same host cannot be members of the same cluster. The value of the GMS_LISTENER_PORT
property must be unique for each cluster in a domain.