| /* |
| * Copyright 2016-present Open Networking Laboratory |
| * |
| * Licensed 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.onosproject.provider.nil; |
| import java.util.Arrays; |
| import static com.google.common.base.Preconditions.checkArgument; |
| |
| /** |
| * Fat-tree topology simulator. |
| */ |
| public class FatTreeTopologySimulator extends TopologySimulator { |
| |
| private static final int DEFAULT_NUMBER_OF_PORTS_PER_SWITCH = 4; |
| protected int kPorts; |
| protected int numberOfPods; |
| protected int numberOfAggLayerSwitches; |
| protected int numberOfCoreLayerSwitches; |
| protected int numberOfEdgeLayerSwitches; |
| |
| @Override |
| protected void processTopoShape(String shape) { |
| super.processTopoShape(shape); |
| |
| // If switch ports are not provided use a default value |
| int k = (topoShape.length == 1) ? |
| DEFAULT_NUMBER_OF_PORTS_PER_SWITCH : |
| Integer.parseInt(topoShape[1]); |
| |
| // A fat-tree is parametrized by the total number of ports per switch. |
| // check top of page 4 of http://web.eecs.umich.edu/~mosharaf/Readings/Fat-Tree.pdf |
| kPorts = k; |
| numberOfPods = k; |
| numberOfCoreLayerSwitches = (k / 2) * (k / 2); |
| numberOfAggLayerSwitches = k * k / 2; |
| numberOfEdgeLayerSwitches = k * k / 2; |
| |
| // need to also change hostCount variable of TopologySimulator |
| hostCount = kPorts / 2; |
| } |
| |
| |
| @Override |
| public void setUpTopology() { |
| |
| checkArgument(kPorts > 1, "Fat Tree switches must " + |
| "have at **least** 2 ports each!"); |
| |
| // this is the total number of **Switches** |
| // in a fat-tree topology |
| deviceCount = numberOfAggLayerSwitches + |
| numberOfCoreLayerSwitches + |
| numberOfEdgeLayerSwitches; |
| |
| log.info("Booting a {} with {}-ports, {} switches in total {} pods", |
| topoShape[0], kPorts, deviceCount, numberOfPods); |
| |
| |
| prepareForDeviceEvents(deviceCount); |
| createDevices(); |
| waitForDeviceEvents(); |
| |
| createLinks(); |
| createHosts(); |
| } |
| |
| @Override |
| protected void createLinks() { |
| |
| // For each switch keep a count of used ports |
| int[] portList = new int[deviceCount]; |
| Arrays.fill(portList, 0); |
| |
| // we assume that deviceIds stores all the fat tree switches in a flat list |
| int end = numberOfPods / 2; |
| // from [ 0, (k/2)^2 - 1] we store (k/2)^2 core switces |
| int startOfCore = 0; |
| // from [ (k/2)^2, (k/2)^2 + (k^2)/2 - 1] we store (k^2)/2 aggregation switches |
| int startOfAgg = (numberOfPods / 2) * (numberOfPods / 2); |
| // from [ (k/2)^2 + (k^2)/2, (k/2)^2 + (k^2)/2 + (k^2)/2 -1] we store (k^2)/2 edge switches |
| int startOfEdge = startOfAgg + (numberOfPods * numberOfPods) / 2; |
| |
| log.debug("startOfCore = {}, startOfAgg = {}, startOfEdge = {}", |
| startOfCore, startOfAgg, startOfEdge); |
| |
| // Create links between core and aggregation switches |
| for (int x = 0; x < numberOfAggLayerSwitches; x += end) { |
| |
| // each agg.switch will handle a group of k/2 core consecutive switches |
| for (int i = 0; i < end; i += 1) { |
| for (int j = 0; j < end; j += 1) { |
| int coreSwitch = i * end + j; |
| int aggSwitch = startOfAgg + x + i; |
| |
| createLink(coreSwitch, |
| aggSwitch, |
| portList[coreSwitch]++, |
| portList[aggSwitch]++); |
| } |
| } |
| } |
| |
| // Create links between aggregation and edge switches |
| for (int x = 0; x < numberOfAggLayerSwitches; x += end) { |
| for (int i = 0; i < end; i += 1) { |
| for (int j = 0; j < end; j += 1) { |
| int aggSwitch = startOfAgg + x + i; |
| int edgeSwitch = startOfEdge + x + j; |
| |
| createLink(aggSwitch, |
| edgeSwitch, |
| portList[aggSwitch]++, |
| portList[edgeSwitch]++); |
| } |
| } |
| } |
| } |
| |
| @Override |
| protected void createHosts() { |
| |
| int firstEdgeSwitch = (numberOfPods / 2) * (numberOfPods / 2) + |
| (numberOfPods * numberOfPods) / 2; |
| |
| // hosts connect **only** to edge switches, each edge switch has k/2 ports free for hosts |
| for (int edgeSwitch = firstEdgeSwitch; edgeSwitch < deviceCount; edgeSwitch++) { |
| |
| createHosts(deviceIds.get(edgeSwitch), kPorts / 2); |
| } |
| } |
| } |