A cluster is a named collection of GlassFish Server instances that share the same applications, resources, and configuration information.
A cluster to provides high availability through scalability, load balancing, and failure protection. When an instance or a host in a cluster fails, GlassFish Server detects the failure, redirects requests from the failed instance to other instances in the cluster, and recovers the user session state. Because the same applications and resources are on all instances in the cluster, an instance can fail over to any other instance in the cluster.
GlassFish Server enables you to administer all the instances in a cluster as a single unit from a single host, regardless of whether the instances reside on the same host or different hosts.
Before You Begin
If you plan to add GlassFish Server instances to the cluster that you are creating, ensure that the nodes on which the instances are to reside already exist.
The Clusters page opens.
The New Cluster page opens.
The name must meet the following requirements:
The name may contain only ASCII characters.
The name must start with a letter, a number, or an underscore.
The name may contain only the following characters:
Lowercase letters
Uppercase letters
Numbers
Hyphen
Period
Underscore
The name must be unique in the domain and must not be the name of a another cluster, a named configuration, a GlassFish Server instance , or a node.
The name must not be domain, server, or any other keyword that is reserved by GlassFish Server.
Note - If you select default-config, you must specify in the next step that the configuration is not shared. The default-config configuration cannot be shared.
The selected configuration is copied when the cluster is created. The copy of the configuration is assigned the name cluster-name-config, where cluster-name is the name of the cluster that you are creating.
The cluster will use the specified existing named configuration.
Note - To create an instance on a node of type CONFIG that represents a remote host, you must use the create-local-instance(1) subcommand. You cannot use the Administration Console for this purpose.
You can also add instances after the cluster is created.
Add each instance as follows:
A row is added to the table of instances in the cluster.
The load-balancing weight determines the proportion of all requests to the cluster that the instance should process.
For example, in a two-instance cluster, you might require one instance to process one out of four requests, and the other instance to process three out of four requests. In this situation, set the weight of the instance that is process one out of four requests to 1 and set the weight of the other instance to 3. If you prefer to use percentages, set the weights of the instances to 25 and 75 respectively.
The default weight is 100.
You are returned to the Clusters page. The cluster is added to the table of clusters on the page.
See Also
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