| package org.apache.helix.controller.rebalancer.strategy; |
| |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| |
| import java.util.LinkedHashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| import org.apache.helix.zookeeper.datamodel.ZNRecord; |
| import org.apache.helix.controller.dataproviders.BaseControllerDataProvider; |
| |
| /** |
| * Assignment strategy interface that computes the assignment of partition->instance. |
| */ |
| public interface RebalanceStrategy<T extends BaseControllerDataProvider> { |
| String DEFAULT_REBALANCE_STRATEGY = "DEFAULT"; |
| |
| /** |
| * Perform the necessary initialization for the rebalance strategy object. |
| * |
| * @param resourceName |
| * @param partitions |
| * @param states |
| * @param maximumPerNode |
| */ |
| void init(String resourceName, final List<String> partitions, |
| final LinkedHashMap<String, Integer> states, int maximumPerNode); |
| |
| /** |
| * Compute the preference lists and (optional partition-state mapping) for the given resource. |
| * |
| * @param liveNodes |
| * @param currentMapping |
| * @param allNodes |
| * @return |
| */ |
| ZNRecord computePartitionAssignment(final List<String> allNodes, final List<String> liveNodes, |
| final Map<String, Map<String, String>> currentMapping, |
| T clusterData); |
| } |