Program guide > (deprecated) Partitioning facility > Manage the partitioning facility environment > Relation of a partition to an HA group

Deprecated feature: The partitioning facility (WPF) feature is deprecated. You can configure partitioning with WebSphere eXtreme Scale.

Partition scope

Partitions have two possible scopes: cluster and node scope. The application specifies the scope when it creates the partition definition for the partition. The partition scope influences the highly available (HA) group properties for the partition at creation time and how the partition's HA group is handled once the cluster starts.

Cluster scoped partitions

Cluster scoped partitioning facility partitions are the default type. In this case, when each member of the cluster creates and joins a partition HA group, only one instance will have a partition endpoint activated. This guarantees that a routing request is sent to a unique cluster member. Cluster scoped partitions are IIOP routable and only activate when the cluster reaches quorum.

Node scoped partitions

A node-scoped partition includes a node attribute in the group properties called -pnn, which has a value of node_name. Node scoped partition naming is detailed below.

If there are five nodes, then there will be five active partitions, as the extra attribute -pnn distinguishes each partition on a separate node from another. For example, on NodeA, serverA, the -pnn attribute would have the value NodeA. All partitions of that type on that logical node (could be N application server cluster members) with that partition's set of similar HA group properties are each set on a specific node establishing their own cluster wide group. Consequently, one of these partitions on NodeA will be activated. For the same partitions created on NodeB, all the partitions would be the same for that application, except the -pnn value would be set to NodeB, uniquely distinguishing them from the node scoped partitions on NodeA.

If a one of N policy matches a node scoped partition then the partition is activated once on every node with a cluster member started. If there are four nodes with cluster members running, then the partition will be activated once on every one of the four nodes.

Node scoped partitions do NOT wait for cluster quorum before activating. Requests to these partition types will be routed based upon a round-robin scheme across members. Thus, for solutions where more than one endpoint can suffice and would be beneficial, node scoped partitions are available.

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Relation of a partition to an HA group

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Relation of a partition to an HA group