com.hazelcast.partition.PartitionService Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2024, 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.partition;
import com.hazelcast.cluster.Member;
import javax.annotation.Nonnull;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
/**
* PartitionService allows you to query {@link Partition}s and attach/detach {@link MigrationListener}s to listen to partition
* migration events.
*
* The methods on the PartitionService are thread-safe.
*
* @see Partition
* @see MigrationListener
* @see PartitionLostListener
*/
public interface PartitionService {
/**
* Returns a set containing all the {@link Partition}s in the cluster.
*
* @return all partitions in the cluster
*/
Set getPartitions();
/**
* Returns the partition that the given key belongs to.
*
* @param key the given key
* @return the partition that the given key belongs to
*/
Partition getPartition(@Nonnull Object key);
/**
* Adds a MigrationListener.
*
* The addMigrationListener returns a register ID. This ID is needed to remove the MigrationListener using the
* {@link #removeMigrationListener(UUID)} method.
*
* There is no check for duplicate registrations, so if you register the listener twice, it will get events twice.
*
* @param migrationListener the added MigrationListener
* @return returns the registration ID for the MigrationListener
* @throws java.lang.NullPointerException if migrationListener is {@code null}
* @throws UnsupportedOperationException if this operation isn't supported. For example on the client side it isn't possible
* to add a MigrationListener
* @see #removeMigrationListener(UUID)
*/
UUID addMigrationListener(MigrationListener migrationListener);
/**
* Removes a MigrationListener.
*
* If the same MigrationListener is registered multiple times, it needs to be removed multiple times.
*
* This method can safely be called multiple times for the same registration ID; every subsequent call is just ignored.
*
* @param registrationId the registration ID of the listener to remove
* @return {@code true} if the listener is removed, {@code false} otherwise
* @throws java.lang.NullPointerException if registration ID is {@code null}
* @throws UnsupportedOperationException if this operation isn't supported, e.g. on the client side it isn't possible
* to add/remove a MigrationListener
* @see #addMigrationListener(MigrationListener)
*/
boolean removeMigrationListener(UUID registrationId);
/**
* Adds a PartitionLostListener.
*
* The addPartitionLostListener returns a registration ID. This ID is needed to remove the PartitionLostListener using the
* {@link #removePartitionLostListener(UUID)} method.
*
* There is no check for duplicate registrations, so if you register the listener twice, it will get events twice.
* IMPORTANT: Please @see com.hazelcast.partition.PartitionLostListener for weaknesses
*
* @param partitionLostListener the added PartitionLostListener
* @return returns the registration ID for the PartitionLostListener
* @throws java.lang.NullPointerException if partitionLostListener is {@code null}
* @see #removePartitionLostListener(UUID)
*/
UUID addPartitionLostListener(PartitionLostListener partitionLostListener);
/**
* Removes a PartitionLostListener.
*
* If the same PartitionLostListener is registered multiple times, it needs to be removed multiple times.
*
* This method can safely be called multiple times for the same registration ID; every subsequent call is just ignored.
*
* @param registrationId the registration ID of the listener to remove
* @return {@code true} if the listener is removed, {@code false} otherwise
* @throws java.lang.NullPointerException if registration ID is {@code null}
* @see #addPartitionLostListener(PartitionLostListener)
*/
boolean removePartitionLostListener(UUID registrationId);
/**
* Checks whether the cluster is in a safe state.
*
* Safe state means; there are no partitions being migrated and all backups are in sync
* when this method is called.
*
* @return {@code true} if there are no partitions being migrated and all backups are in sync, {@code false} otherwise
* @since 3.3
*/
boolean isClusterSafe();
/**
* Checks whether the given member is in safe state.
*
* Safe state means; all backups of partitions currently owned by the member are in sync when this method is called.
*
* @param member the cluster member to query
* @return {@code true} if the member is in a safe state, {@code false} otherwise
* @since 3.3
*/
boolean isMemberSafe(Member member);
/**
* Checks whether local member is in safe state.
*
* Safe state means; all backups of partitions currently owned by local member are in sync when this method is called.
*
* @since 3.3
*/
boolean isLocalMemberSafe();
/**
* Force the local member to be safe by checking and syncing partitions owned by the local member
* with at least one of the backups.
*
* @param timeout the time limit for checking/syncing with the backup
* @param unit the unit of time for timeout
* @since 3.3
*/
boolean forceLocalMemberToBeSafe(long timeout, TimeUnit unit);
}