Event-Driven Architecture
Infinispan notifies your application when data changes. Instead of polling for updates, your services react to cache events in real time — entries created, modified, expired, or removed. This turns Infinispan into an event backbone that connects your components through data changes.
How it works
Infinispan provides two complementary mechanisms for event-driven patterns:
Client listeners: register callbacks on a cache and receive notifications when entries change. Listeners fire on create, modify, remove, and expiration events.
Each event carries the key and metadata so your application can react immediately.
Continuous queries: define a query and Infinispan pushes matching results to your application as data changes.
When a cache entry starts matching the query, you get a Joining event. When it stops matching, a Leaving event. When a matching entry changes, an Updated event.
Use cases
Real-time notifications: alert users or downstream services the moment data changes. A price update in the cache triggers notifications to all interested clients without polling. Data pipelines: chain processing stages through cache events. One service writes enriched data to a cache, another reacts to it, transforms it, and writes results to another cache. Monitoring and alerting: continuous queries watch for threshold breaches. When a metric crosses a boundary, the query engine pushes an event immediately. No periodic scans. Cache synchronization: keep derived data structures, search indexes, or external systems in sync with the authoritative cache. React to changes instead of running batch reconciliation.
Filtering events
Not every event matters to every listener. Infinispan supports server-side event filtering so only relevant events cross the network:
- Key filters: receive events only for specific keys or key patterns.
- Query filters: combine with full-text queries to receive events only when data matches complex conditions.
- Converter factories: transform event payloads on the server before sending them to the client, reducing bandwidth.
Clustered listeners
By default, listeners on a remote client receive events from the entire cluster, regardless of which node processed the write. Infinispan routes events transparently, so your application sees a unified stream of changes across all nodes.
