| /** |
| * 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. |
| */ |
| package org.apache.hadoop.tools.rumen; |
| |
| import java.util.Set; |
| import java.util.Random; |
| |
| /** |
| * {@link ClusterStory} represents all configurations of a MapReduce cluster, |
| * including nodes, network topology, and slot configurations. |
| */ |
| public interface ClusterStory { |
| /** |
| * Get all machines of the cluster. |
| * @return A read-only set that contains all machines of the cluster. |
| */ |
| public Set<MachineNode> getMachines(); |
| |
| /** |
| * Get all racks of the cluster. |
| * @return A read-only set that contains all racks of the cluster. |
| */ |
| public Set<RackNode> getRacks(); |
| |
| /** |
| * Get the cluster topology tree. |
| * @return The root node of the cluster topology tree. |
| */ |
| public Node getClusterTopology(); |
| |
| /** |
| * Select a random set of machines. |
| * @param expected The expected sample size. |
| * @param random Random number generator to use. |
| * @return An array of up to expected number of {@link MachineNode}s. |
| */ |
| public MachineNode[] getRandomMachines(int expected, Random random); |
| |
| /** |
| * Get {@link MachineNode} by its host name. |
| * |
| * @return The {@link MachineNode} with the same name. Or null if not found. |
| */ |
| public MachineNode getMachineByName(String name); |
| |
| /** |
| * Get {@link RackNode} by its name. |
| * @return The {@link RackNode} with the same name. Or null if not found. |
| */ |
| public RackNode getRackByName(String name); |
| |
| /** |
| * Determine the distance between two {@link Node}s. Currently, the distance |
| * is loosely defined as the length of the longer path for either a or b to |
| * reach their common ancestor. |
| * |
| * @param a |
| * @param b |
| * @return The distance between {@link Node} a and {@link Node} b. |
| */ |
| int distance(Node a, Node b); |
| |
| /** |
| * Get the maximum distance possible between any two nodes. |
| * @return the maximum distance possible between any two nodes. |
| */ |
| int getMaximumDistance(); |
| } |