Cluster

 

The following procedures describe how to use the Administration Console to set the attributes for configuring and managing clusters. For additional information about clusters, please see Configuring WebLogic Servers and Clusters in the Administration Guide and Using WebLogic Server Clusters.

 

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Configure a Cluster

1. Click the Clusters node in the left pane. The Clusters table displays in the right pane showing all the clusters defined in the domain.

2. Click the Configure a New Cluster link. A dialog displays in the right pane showing the tabs associated with configuring a new cluster.

3. Enter values in the Name, Default Load Algorithm, and Service Age Threshold attribute fields.

Note: Assign a unique name to the cluster. Each configurable resource in your WebLogic environment should have a unique name.

1. Enter a value for the Cluster Address. Supply a cluster address that identifies the Managed Servers in the cluster. The cluster address is used in entity and stateless beans to construct the host name portion of URLs. If the cluster address is not set, EJB handles may not work properly.

   For production systems, this address should be a DNS host name that maps to the individual IP addresses of the Managed Servers participating in the cluster. For development (non-production) systems, this address can be either a DNS host name or a comma-separated list of single address host names or IP addresses. For more information on the cluster address format, see Cluster Address" in Using WebLogic Server Clusters.

2. Click the Create button in the lower right corner to create a cluster with the name you specified in the Name field. The new cluster is added under the Clusters node in the left pane.

3. Click the Multicast tab and change the Send Delay and TTL attribute fields or accept the default values as assigned. The valid range of multicast addresses is from 224.0.0.1 to 239.255.255.255.

4. Click the Apply button in the lower right corner of each tab to save any changes you made.

 

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Clone a Cluster

1. Click the Clusters node in the left pane. The Clusters table displays in the right pane showing all the clusters defined in the domain.

2. Click the Clone icon in the row of the cluster you want to clone. A dialog displays in the right pane showing the tabs associated with cloning a cluster.

3. Enter values in the Name, Cluster Address, Default Load Algorithm, and Service Age Threshold attribute fields

4. Click the Clone button in the lower right corner to create a cluster instance with the name you specified in the Name field. The new instance is added under the Clusters node in the left pane.

5. Click the Multicast tab and change the attribute fields or accept the default values as assigned.

6. Click the Apply button in the lower right corner of each tab to save any changes you made.

 

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Delete a Cluster

1. Click the Clusters node in the left pane. The Clusters table displays in the right pane showing all the clusters defined in the domain.

2. Click the Delete icon in the row of the cluster you want to delete. A dialog displays in the right pane asking you to confirm your deletion request.

3. Click the Yes button to delete the cluster. The cluster icon under the Clusters node is deleted.

 

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Assign Servers to a Cluster

1. Click the instance node in the left pane under Clusters to select a cluster for server assignment. A dialog displays in the right pane showing the tabs associated with this instance.

2. Click the Servers tab.

3. Select one or more servers in the Available column that you want to assign to the cluster.

4. Click the mover control to move the servers you selected to the Chosen column.

5. Click the Apply button in the lower right corner to save your assignments.

 

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Monitor Server Participation in a Cluster

1. Click the instance node in the left pane under Clusters to select a cluster for server monitoring. A dialog displays in the right pane showing the tabs associated with this instance.

2. Click the Monitoring tab.

3. Click the Monitor Server Participation in This Cluster text link. The server table displays in the right pane showing all the servers assigned to this cluster.

 

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Configuration

General

Attribute	Description	Range of Values	Default Value
Name	This attribute reports the name of the cluster.	The cluster name can be up to 256 alphanumeric characters, but may not contain commas or spaces.	Null
Cluster Address	This attribute returns the address to be used by clients to connect to this cluster. This address may be either a DNS host name that maps to multiple IP addresses or a comma separated list of single address host names or IP addresses.	This address may be either a DNS host name that maps to multiple IP addresses or a comma separated list of single address host names or IP addresses.	Null
Default Load Algorithm	The default cluster load algorithm is the algorithm by which the load is distributed. When the last server has been assigned a transaction, the load comes back to the starting server.	Round Robin, Weight- based Round Robin, Random, and Parameter-based Routing	Round Robin
WebLogic Plug-In Enabled	A value of true for a cluster that receives requests from HttpClusterServlet. causes getRemoteAddr to return the address of the browser client from the proprietary WL-Proxy-Client-IP header, instead of the web server. For non-clustered servers that will receive proxied requests, this attribute may be set at the server level, on the Server -->Configuration-->General tab. MBean: weblogic.management.configuration.ClusterMBean Attribute: WeblogicPluginEnabled Note: This attribute is duplicated in ServerMBean. The value in ClusterMBean overrides ServerMBean.	true false	false
Service Age Threshold	This attribute describes the number of seconds by which the age of two conflicting services must differ before one is considered older than the other.	Integer (seconds)	180

Multicast

Attribute	Description	Range of Values	Default Value
Multicast Address	The cluster multicast address sets the multicast address used by cluster members to communicate with each other. It must be a well-formed IP address.	The valid range of multicast addresses is from 224.0.0.1 to 239.255.255.255	Null
Multicast Send Delay	This attribute returns the number of milliseconds to delay sending message fragments over multicast in order to avoid OS-level buffer overflow.	Integer	12
Multicast TTL	This attribute returns the number of the multicast ttl.	Integer	1

Servers

Attribute	Description	Range of Values	Default Value
Choose Servers for this Cluster	This attribute allows the user to choose servers to participate in this cluster.	List	Null

Monitoring

Attribute	Description	Range of Values	Default Value
Number of Servers Configured for this Cluster	This attribute returns the number of servers that have been configured to run in this cluster.	Integer	0
Number of Servers Currently Participating in this Cluster	This attribute returns the number of servers running in this cluster.	Integer	0

Notes

Attribute	Description	Range of Values	Default Value
Notes	This attribute provides a space for optional user supplied information.	The value must be an alphanumeric string.	Null