Andreas Pantelopoulos | 620d3d7 | 2016-11-08 22:18:59 +0100 | [diff] [blame] | 1 | /* |
Brian O'Connor | a09fe5b | 2017-08-03 21:12:30 -0700 | [diff] [blame] | 2 | * Copyright 2016-present Open Networking Foundation |
Andreas Pantelopoulos | 620d3d7 | 2016-11-08 22:18:59 +0100 | [diff] [blame] | 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.onosproject.provider.nil; |
| 17 | import java.util.Arrays; |
| 18 | import static com.google.common.base.Preconditions.checkArgument; |
| 19 | |
| 20 | /** |
| 21 | * Fat-tree topology simulator. |
| 22 | */ |
| 23 | public class FatTreeTopologySimulator extends TopologySimulator { |
| 24 | |
| 25 | private static final int DEFAULT_NUMBER_OF_PORTS_PER_SWITCH = 4; |
| 26 | protected int kPorts; |
| 27 | protected int numberOfPods; |
| 28 | protected int numberOfAggLayerSwitches; |
| 29 | protected int numberOfCoreLayerSwitches; |
| 30 | protected int numberOfEdgeLayerSwitches; |
| 31 | |
| 32 | @Override |
| 33 | protected void processTopoShape(String shape) { |
| 34 | super.processTopoShape(shape); |
| 35 | |
| 36 | // If switch ports are not provided use a default value |
| 37 | int k = (topoShape.length == 1) ? |
| 38 | DEFAULT_NUMBER_OF_PORTS_PER_SWITCH : |
| 39 | Integer.parseInt(topoShape[1]); |
| 40 | |
| 41 | // A fat-tree is parametrized by the total number of ports per switch. |
| 42 | // check top of page 4 of http://web.eecs.umich.edu/~mosharaf/Readings/Fat-Tree.pdf |
| 43 | kPorts = k; |
| 44 | numberOfPods = k; |
| 45 | numberOfCoreLayerSwitches = (k / 2) * (k / 2); |
| 46 | numberOfAggLayerSwitches = k * k / 2; |
| 47 | numberOfEdgeLayerSwitches = k * k / 2; |
| 48 | |
| 49 | // need to also change hostCount variable of TopologySimulator |
| 50 | hostCount = kPorts / 2; |
| 51 | } |
| 52 | |
| 53 | |
| 54 | @Override |
| 55 | public void setUpTopology() { |
| 56 | |
| 57 | checkArgument(kPorts > 1, "Fat Tree switches must " + |
| 58 | "have at **least** 2 ports each!"); |
| 59 | |
| 60 | // this is the total number of **Switches** |
| 61 | // in a fat-tree topology |
| 62 | deviceCount = numberOfAggLayerSwitches + |
| 63 | numberOfCoreLayerSwitches + |
| 64 | numberOfEdgeLayerSwitches; |
| 65 | |
| 66 | log.info("Booting a {} with {}-ports, {} switches in total {} pods", |
| 67 | topoShape[0], kPorts, deviceCount, numberOfPods); |
| 68 | |
| 69 | |
| 70 | prepareForDeviceEvents(deviceCount); |
| 71 | createDevices(); |
| 72 | waitForDeviceEvents(); |
| 73 | |
| 74 | createLinks(); |
| 75 | createHosts(); |
| 76 | } |
| 77 | |
| 78 | @Override |
| 79 | protected void createLinks() { |
| 80 | |
| 81 | // For each switch keep a count of used ports |
| 82 | int[] portList = new int[deviceCount]; |
| 83 | Arrays.fill(portList, 0); |
| 84 | |
| 85 | // we assume that deviceIds stores all the fat tree switches in a flat list |
| 86 | int end = numberOfPods / 2; |
| 87 | // from [ 0, (k/2)^2 - 1] we store (k/2)^2 core switces |
| 88 | int startOfCore = 0; |
| 89 | // from [ (k/2)^2, (k/2)^2 + (k^2)/2 - 1] we store (k^2)/2 aggregation switches |
| 90 | int startOfAgg = (numberOfPods / 2) * (numberOfPods / 2); |
| 91 | // from [ (k/2)^2 + (k^2)/2, (k/2)^2 + (k^2)/2 + (k^2)/2 -1] we store (k^2)/2 edge switches |
| 92 | int startOfEdge = startOfAgg + (numberOfPods * numberOfPods) / 2; |
| 93 | |
| 94 | log.debug("startOfCore = {}, startOfAgg = {}, startOfEdge = {}", |
| 95 | startOfCore, startOfAgg, startOfEdge); |
| 96 | |
| 97 | // Create links between core and aggregation switches |
| 98 | for (int x = 0; x < numberOfAggLayerSwitches; x += end) { |
| 99 | |
| 100 | // each agg.switch will handle a group of k/2 core consecutive switches |
| 101 | for (int i = 0; i < end; i += 1) { |
| 102 | for (int j = 0; j < end; j += 1) { |
| 103 | int coreSwitch = i * end + j; |
| 104 | int aggSwitch = startOfAgg + x + i; |
| 105 | |
| 106 | createLink(coreSwitch, |
| 107 | aggSwitch, |
| 108 | portList[coreSwitch]++, |
| 109 | portList[aggSwitch]++); |
| 110 | } |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | // Create links between aggregation and edge switches |
| 115 | for (int x = 0; x < numberOfAggLayerSwitches; x += end) { |
| 116 | for (int i = 0; i < end; i += 1) { |
| 117 | for (int j = 0; j < end; j += 1) { |
| 118 | int aggSwitch = startOfAgg + x + i; |
| 119 | int edgeSwitch = startOfEdge + x + j; |
| 120 | |
| 121 | createLink(aggSwitch, |
| 122 | edgeSwitch, |
| 123 | portList[aggSwitch]++, |
| 124 | portList[edgeSwitch]++); |
| 125 | } |
| 126 | } |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | @Override |
| 131 | protected void createHosts() { |
| 132 | |
| 133 | int firstEdgeSwitch = (numberOfPods / 2) * (numberOfPods / 2) + |
| 134 | (numberOfPods * numberOfPods) / 2; |
| 135 | |
| 136 | // hosts connect **only** to edge switches, each edge switch has k/2 ports free for hosts |
| 137 | for (int edgeSwitch = firstEdgeSwitch; edgeSwitch < deviceCount; edgeSwitch++) { |
| 138 | |
| 139 | createHosts(deviceIds.get(edgeSwitch), kPorts / 2); |
| 140 | } |
| 141 | } |
| 142 | } |