| package org.apache.helix.controller.rebalancer.waged.model; |
| |
| /* |
| * 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.Collections; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.stream.Collectors; |
| |
| import org.apache.helix.HelixException; |
| |
| /** |
| * This class wraps the required input for the rebalance algorithm. |
| */ |
| public class ClusterModel { |
| private final ClusterContext _clusterContext; |
| // Map to track all the assignable replications. <Resource Name, Set<Replicas>> |
| private final Map<String, Set<AssignableReplica>> _assignableReplicaMap; |
| // The index to find the replication information with a certain state. <Resource, <Key(resource_partition_state), Replica>> |
| // Note that the identical replicas are deduped in the index. |
| private final Map<String, Map<String, AssignableReplica>> _assignableReplicaIndex; |
| private final Map<String, AssignableNode> _assignableNodeMap; |
| |
| /** |
| * @param clusterContext The initialized cluster context. |
| * @param assignableReplicas The replicas to be assigned. |
| * Note that the replicas in this list shall not be included while initializing the context and assignable nodes. |
| * @param assignableNodes The active instances. |
| */ |
| ClusterModel(ClusterContext clusterContext, Set<AssignableReplica> assignableReplicas, |
| Set<AssignableNode> assignableNodes) { |
| _clusterContext = clusterContext; |
| |
| // Save all the to be assigned replication |
| _assignableReplicaMap = assignableReplicas.stream() |
| .collect(Collectors.groupingBy(AssignableReplica::getResourceName, Collectors.toSet())); |
| |
| // Index all the replicas to be assigned. Dedup the replica if two instances have the same resource/partition/state |
| _assignableReplicaIndex = assignableReplicas.stream().collect(Collectors |
| .groupingBy(AssignableReplica::getResourceName, Collectors |
| .toMap(AssignableReplica::toString, replica -> replica, |
| (oldValue, newValue) -> oldValue))); |
| |
| _assignableNodeMap = assignableNodes.stream() |
| .collect(Collectors.toMap(AssignableNode::getInstanceName, node -> node)); |
| } |
| |
| public ClusterContext getContext() { |
| return _clusterContext; |
| } |
| |
| public Map<String, AssignableNode> getAssignableNodes() { |
| return _assignableNodeMap; |
| } |
| |
| public Map<String, Set<AssignableReplica>> getAssignableReplicaMap() { |
| return _assignableReplicaMap; |
| } |
| |
| /** |
| * Assign the given replica to the specified instance and record the assignment in the cluster model. |
| * The cluster usage information will be updated accordingly. |
| * |
| * @param resourceName |
| * @param partitionName |
| * @param state |
| * @param instanceName |
| */ |
| public void assign(String resourceName, String partitionName, String state, String instanceName) { |
| AssignableNode node = locateAssignableNode(instanceName); |
| AssignableReplica replica = locateAssignableReplica(resourceName, partitionName, state); |
| |
| node.assign(replica); |
| _clusterContext.addPartitionToFaultZone(node.getFaultZone(), resourceName, partitionName); |
| } |
| |
| /** |
| * Revert the proposed assignment from the cluster model. |
| * The cluster usage information will be updated accordingly. |
| * |
| * @param resourceName |
| * @param partitionName |
| * @param state |
| * @param instanceName |
| */ |
| public void release(String resourceName, String partitionName, String state, |
| String instanceName) { |
| AssignableNode node = locateAssignableNode(instanceName); |
| AssignableReplica replica = locateAssignableReplica(resourceName, partitionName, state); |
| |
| node.release(replica); |
| _clusterContext.removePartitionFromFaultZone(node.getFaultZone(), resourceName, partitionName); |
| } |
| |
| private AssignableNode locateAssignableNode(String instanceName) { |
| AssignableNode node = _assignableNodeMap.get(instanceName); |
| if (node == null) { |
| throw new HelixException("Cannot find the instance: " + instanceName); |
| } |
| return node; |
| } |
| |
| private AssignableReplica locateAssignableReplica(String resourceName, String partitionName, |
| String state) { |
| AssignableReplica sampleReplica = |
| _assignableReplicaIndex.getOrDefault(resourceName, Collections.emptyMap()) |
| .get(AssignableReplica.generateReplicaKey(resourceName, partitionName, state)); |
| if (sampleReplica == null) { |
| throw new HelixException(String |
| .format("Cannot find the replication with resource name %s, partition name %s, state %s.", |
| resourceName, partitionName, state)); |
| } |
| return sampleReplica; |
| } |
| } |