Resource Scope

It is important to understand that the scope of a cell’s configuration controls the visibility of that resource to other resources and application server instances. An example of a resource might be a data source definition, or a WebSphere variable definition.

Scopes are typically defined as being one of the following:
● Cell – All resources defined at this scope are visible to all other resources defined in the
cell, and are thus configured globally available.
● Node – A cell has one or more nodes. Each node is named and matches with some
WebSphere Application Server profile on some physical server. All resources defined at this scope are visible only to other resources defined in this same node, including any server definitions.
● Server – A node has one or more server definitions. All resources defined at this scope are visible only to that server. No other server or node can use these resources.
● Cluster – A resource defined at a cluster scope is visible to all cluster members, or server instances, in this cluster; this resource is not visible to any other servers in the same nodes.

All enterprise applications are cell scoped because only one enterprise application with a given name can be present in a cell. If multiple servers and clusters, or
multiple clusters, require the use of that enterprise application, they
must share it.

IBM WebSphere Application Server Extended Deployment offers the capability manage multiple editions of the same enterprise application, including the mapping of these editions to different servers and clusters, or to different clusters. WebSphere Portal, however, does not currently exploit this feature.

Typically, when installing an enterprise application that will be shared across multiple clusters, the administrator simply installs the enterprise application archive (EAR) into the cell’s management server, Deployment Manager, and then maps the application to the target clusters where it will run

The Java 2 Platform, Enterprise Edition (J2EE) security configuration for the cell is shared by all servers and clusters managed in the cell. Therefore, each server and cluster must share the same underlying user repository against which users are authenticated when they use any application hosted by any server or cluster in that same cell