org.infinispan.affinity

Interface KeyAffinityService<K>

All Superinterfaces:

Lifecycle

All Known Implementing Classes:

KeyAffinityServiceImpl, KeyAffinityServiceImpl

public interface KeyAffinityService<K>
extends Lifecycle

Defines a service that generates keys to be mapped to specific nodes in a distributed(vs. replicated) cluster. The service is instantiated through through one of the factory methods from KeyAffinityServiceFactory.

Sample usage:

    Cache<String, Long> cache = getDistributedCache();
    KeyAffinityService<String> service = KeyAffinityServiceFactory.newKeyAffinityService(cache, 100);
    ...
    String sessionId = sessionObject.getId();
    String newCollocatedSession = service.getCollocatedKey(sessionId);

    //this will reside on the same node in the cluster
    cache.put(newCollocatedSession, someInfo);
 

Uniqueness: the service does not guarantee that the generated keys are unique. It relies on an KeyGenerator for obtaining and distributing the generated keys. If key uniqueness is needed that should be enforced in the generator.

The service might also drop key generated through the KeyGenerator.

Since:

4.1

Author:

Mircea.Markus@jboss.com

See Also:

KeyAffinityServiceFactory

Method Summary

Modifier and Type	Method and Description
K	getCollocatedKey(K otherKey) Returns a key that will be distributed on the same node as the supplied key.
K	getKeyForAddress(Address address) Returns a key that will be distributed on the cluster node identified by address.
boolean	isStarted() Checks weather or not the service is started.

Methods inherited from interface org.infinispan.commons.api.Lifecycle

start, stop

Method Detail

getKeyForAddress

K getKeyForAddress(Address address)

Returns a key that will be distributed on the cluster node identified by address.

Parameters:

address - identifying the cluster node.

Returns:

a key object

Throws:

IllegalStateException - if the service has not been started or it is shutdown

getCollocatedKey

K getCollocatedKey(K otherKey)

Returns a key that will be distributed on the same node as the supplied key.

Parameters:

otherKey - the key for which we need a collocation

Returns:

a key object

Throws:

IllegalStateException - if the service has not been started or it is shutdown

isStarted

boolean isStarted()

Checks weather or not the service is started.