Rhino versions prior to 3.0.0 had two modes of operation for managing the activation state of services and resource adaptor entities: per-node and symmetric. From Rhino 3.0.0 these two modes were combined and have been superseded by default desired state which can be overridden by per-node desired state. Per-node desired state overrides default desired state if present. Default desired state is effective if no per-node desired state exists.
The actual state for all functions is always maintained on a per-node basis.
Per-node activation state
In per-node activation state mode, Rhino maintained activation state for the installed services and created resource adaptor entities in a namespace on a per-node basis. That is, the SLEE recorded separate activation state information for each individual cluster node.
The per-node activation state mode was the default mode in a newly installed Rhino cluster.
Symmetric activation state
In the symmetric activation state mode, Rhino maintained a single cluster-wide activation state view for each installed service and created resource adaptor entity. So, for example, if a service was activated, then it was simultaneously activated on every cluster node. If a new node joined the cluster, then the services and resource adaptor entities on that node each entered the same operational state as for existing cluster nodes.
Default and per-node desired state and actual state
In Rhino 3.0.0, a default activation state for the SLEE, an installed service, or a created resource adaptor entity is configured for all nodes in the cluster with optional overrides configured on a per-node basis. The effective desired state for a node is the per-node state, or the default state if no per-node state exists for a given function. If it is desired to manage the state of a cluster in the way previously served by symmetric activation state mode, the default state should be used and per-node state left unconfigured. Commands for managing per-node desired state can be found under the topic Per-Node Desired State.
In operation, Rhino nodes have an actual state that is the current operational state. The actual state follows the desired state with a per-node convergence subsystem managing transitions between actual states as the lifecycle rules of system functions allow.
These terms are defined under Declarative Configuration Concepts and Terminology.
