| /** |
| * 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 |
| * <p> |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * <p> |
| * 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.storm.networktopography; |
| |
| import java.util.HashSet; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * This is a base class for DNS to Switch mappings. |
| * |
| * It is not mandatory to |
| * derive {@link DNSToSwitchMapping} implementations from it, but it is strongly |
| * recommended, as it makes it easy for the developers to add new methods |
| * to this base class that are automatically picked up by all implementations. |
| * |
| */ |
| public abstract class AbstractDNSToSwitchMapping |
| implements DNSToSwitchMapping { |
| |
| /** |
| * Create an unconfigured instance |
| */ |
| protected AbstractDNSToSwitchMapping() { |
| } |
| |
| /** |
| * Predicate that indicates that the switch mapping is known to be |
| * single-switch. The base class returns false: it assumes all mappings are |
| * multi-rack. Subclasses may override this with methods that are more aware |
| * of their topologies. |
| * |
| * |
| * |
| * @return true if the mapping thinks that it is on a single switch |
| */ |
| public boolean isSingleSwitch() { |
| return false; |
| } |
| |
| /** |
| * Get a copy of the map (for diagnostics) |
| * @return a clone of the map or null for none known |
| */ |
| public Map<String, String> getSwitchMap() { |
| return null; |
| } |
| |
| /** |
| * Generate a string listing the switch mapping implementation, |
| * the mapping for every known node and the number of nodes and |
| * unique switches known about -each entry to a separate line. |
| * |
| * @return a string that can be presented to the ops team or used in |
| * debug messages. |
| */ |
| public String dumpTopology() { |
| Map<String, String> rack = getSwitchMap(); |
| StringBuilder builder = new StringBuilder(); |
| builder.append("Mapping: ").append(toString()).append("\n"); |
| if (rack != null) { |
| builder.append("Map:\n"); |
| Set<String> switches = new HashSet<>(); |
| for (Map.Entry<String, String> entry : rack.entrySet()) { |
| builder.append(" ") |
| .append(entry.getKey()) |
| .append(" -> ") |
| .append(entry.getValue()) |
| .append("\n"); |
| switches.add(entry.getValue()); |
| } |
| builder.append("Nodes: ").append(rack.size()).append("\n"); |
| builder.append("Switches: ").append(switches.size()).append("\n"); |
| } else { |
| builder.append("No topology information"); |
| } |
| return builder.toString(); |
| } |
| |
| } |