Package io.axoniq.framework.messaging.queryhandling.distributed

Interface LocalQueryDispatchPredicate

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface LocalQueryDispatchPredicate

Predicate deciding whether a QueryMessage that is about to be dispatched through a QueryBusConnector should be handled by the local segment directly (taking a "local shortcut") instead of being routed by the connector, which may hand the query to a different segment.

Registering an implementation of this functional interface activates the LocalShortcutQueryBusConnector automatically.

The predicate is consulted for every outgoing direct query, but only takes effect when the local segment actually subscribed a handler for the query. When it did not, the query is routed as usual regardless of this predicate's outcome. Subscription queries are never shortcut and never consult this predicate as their update registrations must be coordinated across all nodes.

Since:

5.4.0

Author:

Allard Buijze

See Also:

• LocalShortcutQueryBusConnector

Method Summary

Modifier and Type	Method	Description
boolean	shouldDispatchLocally(QueryMessage query, @Nullable ProcessingContext context)	Indicates whether the given query should be dispatched to the local segment directly, rather than being routed through the connector.

Method Details

shouldDispatchLocally

boolean shouldDispatchLocally(QueryMessage query,
 @Nullable ProcessingContext context)

Indicates whether the given query should be dispatched to the local segment directly, rather than being routed through the connector.

Parameters:

query - the query message about to be dispatched

context - the processing context active for the dispatch, or null when the query is dispatched outside of an existing processing context

Returns:

true to attempt to dispatch the query to the local segment, false to route it through the connector as usual