/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.spi;
import java.util.Collection;
/**
* {@code FragmentedMigrationAwareService} is an extension to the {@link MigrationAwareService} which allows
* migration/replication of partition replicas in smaller fragments.
* <p>
* Each replica fragment is distinguished by a {@link ServiceNamespace}, all replica data belonging to
* a specific namespace will be transferred in the same packet.
* <p>
* Both backup and backup aware operations created by {@code FragmentedMigrationAwareService} must implement
* {@link ServiceNamespaceAware} interface and must know their related {@link ServiceNamespace}s.
* <p>
* Fragmented migration can be enabled/disabled using configuration property
* {@link com.hazelcast.spi.properties.GroupProperty#PARTITION_FRAGMENTED_MIGRATION_ENABLED}. Anti-entropy system which
* detects and completes inconsistent backup replicas, always uses fragmented replication for services having support.
*
* @see MigrationAwareService
* @see ServiceNamespace
* @see ServiceNamespaceAware
* @since 3.9
*/
public interface FragmentedMigrationAwareService extends MigrationAwareService {
/**
* Returns all known namespaces for given replication event.
*
* @param event replication event
* @return all known service namespaces for the replication
*/
Collection<ServiceNamespace> getAllServiceNamespaces(PartitionReplicationEvent event);
/**
* Returns true if namespace is known by this service, false otherwise
*
* @param namespace namespace
* @return true if namespace is known by this service, false otherwise
*/
boolean isKnownServiceNamespace(ServiceNamespace namespace);
/**
* Returns an operation to replicate service data and/or state for a specific partition replica and namespaces
* on another cluster member. This method is very similar to
* {@link #prepareReplicationOperation(PartitionReplicationEvent)},
* instead of copying whole partition replica, allows copying only some portion of replica,
* specified by given namespaces.
*
* <p>
* This method will be called on source member whenever partitioning system requires
* to copy/replicate a partition replica. Returned operation will be executed on destination member.
* If operation fails by throwing exception, migration process will fail and will be rolled back.
* <p>
* Returning null is allowed and means service does not have anything to replicate.
*
* @param event replication event
* @param namespaces replica fragment namespaces to replicate
* @return replication operation or null if nothing will be replicated
* @see #prepareReplicationOperation(PartitionReplicationEvent)
*/
Operation prepareReplicationOperation(PartitionReplicationEvent event, Collection<ServiceNamespace> namespaces);
}