Consistent Event Notification

GeoServer is most often deployed as a single server application. Several extensions introduce clustering to GeoServer using a form of event notification to communicate application configuration / status to nodes in the cluster.

Since clustering is an advanced deployment operation new functionality is not necessary being tested/designed with clustering in mind. This puts the application in position to wrack up technical debt when new features are deployed in a clustered environment.

Here are examples of stateful features along with options for making them work in a clustered environment:

• catalog: ** jms cluster notification - events include enough detail to keep catalog data structure up to date ** hz cluster plugin - events invalidate catalog data structure, allowing it be lazily restored from jdbc config
• resources - TBD
• geofence - stores security configuration in a BDB database
• importer - store status in a BDB backend
• wps hazelcast - uses a distributed hashmap to preserve asynchronous job status across nodes in cluster