Aaron Kruglikov | 2932798 | 2015-10-06 17:15:16 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2015 Open Networking Laboratory |
| 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 | |
| 17 | package org.onosproject.mlb; |
| 18 | |
| 19 | import com.google.common.util.concurrent.ListenableScheduledFuture; |
| 20 | import com.google.common.util.concurrent.ListeningScheduledExecutorService; |
| 21 | import com.google.common.util.concurrent.MoreExecutors; |
Madan Jampani | 620f70d | 2016-01-30 22:22:47 -0800 | [diff] [blame] | 22 | |
Aaron Kruglikov | 2932798 | 2015-10-06 17:15:16 -0700 | [diff] [blame] | 23 | import org.apache.felix.scr.annotations.Activate; |
| 24 | import org.apache.felix.scr.annotations.Component; |
| 25 | import org.apache.felix.scr.annotations.Deactivate; |
| 26 | import org.apache.felix.scr.annotations.Reference; |
| 27 | import org.apache.felix.scr.annotations.ReferenceCardinality; |
| 28 | import org.onosproject.cluster.ClusterService; |
| 29 | import org.onosproject.cluster.LeadershipEvent; |
| 30 | import org.onosproject.cluster.LeadershipEventListener; |
| 31 | import org.onosproject.cluster.LeadershipService; |
| 32 | import org.onosproject.cluster.NodeId; |
| 33 | import org.onosproject.mastership.MastershipAdminService; |
| 34 | import org.onosproject.mastership.MastershipEvent; |
| 35 | import org.onosproject.mastership.MastershipListener; |
| 36 | import org.onosproject.mastership.MastershipService; |
| 37 | import org.slf4j.Logger; |
| 38 | |
| 39 | import java.util.concurrent.Executors; |
| 40 | import java.util.concurrent.Future; |
| 41 | import java.util.concurrent.TimeUnit; |
| 42 | import java.util.concurrent.atomic.AtomicBoolean; |
| 43 | import java.util.concurrent.atomic.AtomicReference; |
| 44 | |
| 45 | import static org.slf4j.LoggerFactory.getLogger; |
| 46 | |
| 47 | /** |
| 48 | * An app to perform automatic load balancing in response to events. Load balancing events are triggered by any |
| 49 | * change in mastership and are limited to a frequency of one every 30 seconds, all load balancing is run on an outside |
| 50 | * thread executor that must only have one thread due to issues that can occur is multiple balancing events occur in |
| 51 | * parallel. |
| 52 | */ |
| 53 | @Component(immediate = true) |
| 54 | public class MastershipLoadBalancer { |
| 55 | |
| 56 | private final Logger log = getLogger(getClass()); |
| 57 | |
| 58 | private static final String REBALANCE_MASTERSHIP = "rebalance/mastership"; |
| 59 | |
| 60 | private NodeId localId; |
| 61 | |
| 62 | private AtomicBoolean isLeader = new AtomicBoolean(false); |
| 63 | |
| 64 | private AtomicReference<Future> nextTask = new AtomicReference<>(); |
| 65 | |
| 66 | @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY) |
| 67 | protected MastershipService mastershipService; |
| 68 | |
| 69 | @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY) |
| 70 | protected MastershipAdminService mastershipAdminService; |
| 71 | |
| 72 | @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY) |
| 73 | protected LeadershipService leadershipService; |
| 74 | |
| 75 | @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY) |
| 76 | protected ClusterService clusterService; |
| 77 | |
| 78 | private InnerLeadershipListener leadershipListener = new InnerLeadershipListener(); |
| 79 | |
| 80 | /* This listener is used to trigger balancing for any mastership event which will include switches changing state |
| 81 | between active and inactive states as well as the same variety of event occurring with ONOS nodes. Must |
| 82 | use a listenable executor to ensure events are triggered with no frequency greater than once every 30 seconds. |
| 83 | */ |
| 84 | private InnerMastershipListener mastershipListener = new InnerMastershipListener(); |
| 85 | |
| 86 | //Ensures that all executions do not interfere with one another (single thread) |
| 87 | private ListeningScheduledExecutorService executorService = MoreExecutors. |
| 88 | listeningDecorator(Executors.newSingleThreadScheduledExecutor()); |
| 89 | |
| 90 | @Activate |
| 91 | public void activate() { |
| 92 | mastershipService.addListener(mastershipListener); |
| 93 | localId = clusterService.getLocalNode().id(); |
| 94 | leadershipService.addListener(leadershipListener); |
| 95 | leadershipService.runForLeadership(REBALANCE_MASTERSHIP); |
| 96 | log.info("Started"); |
| 97 | } |
| 98 | |
| 99 | @Deactivate |
| 100 | public void deactivate() { |
| 101 | mastershipService.removeListener(mastershipListener); |
| 102 | leadershipService.withdraw(REBALANCE_MASTERSHIP); |
| 103 | leadershipService.removeListener(leadershipListener); |
| 104 | cancelBalance(); |
| 105 | executorService.shutdown(); |
| 106 | log.info("Stopped"); |
| 107 | } |
| 108 | |
Madan Jampani | 620f70d | 2016-01-30 22:22:47 -0800 | [diff] [blame] | 109 | private synchronized void processLeaderChange(NodeId newLeader) { |
Aaron Kruglikov | 2932798 | 2015-10-06 17:15:16 -0700 | [diff] [blame] | 110 | boolean currLeader = newLeader.equals(localId); |
| 111 | if (isLeader.getAndSet(currLeader) != currLeader) { |
| 112 | if (currLeader) { |
| 113 | scheduleBalance(); |
| 114 | } else { |
| 115 | cancelBalance(); |
| 116 | } |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | private void scheduleBalance() { |
| 121 | if (isLeader.get() && nextTask.get() == null) { |
| 122 | |
| 123 | ListenableScheduledFuture task = executorService.schedule(mastershipAdminService::balanceRoles, 30, |
| 124 | TimeUnit.SECONDS); |
| 125 | task.addListener(() -> { |
| 126 | log.info("Completed balance roles"); |
| 127 | nextTask.set(null); |
| 128 | }, MoreExecutors.directExecutor() |
| 129 | ); |
| 130 | if (!nextTask.compareAndSet(null, task)) { |
| 131 | task.cancel(false); |
| 132 | } |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | private void cancelBalance() { |
| 137 | Future task = nextTask.getAndSet(null); |
| 138 | if (task != null) { |
| 139 | task.cancel(false); |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | private class InnerMastershipListener implements MastershipListener { |
| 144 | |
| 145 | @Override |
| 146 | public void event(MastershipEvent event) { |
| 147 | //Sets flag at execution to indicate there is currently a scheduled rebalancing, reverts upon completion |
| 148 | scheduleBalance(); |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | private class InnerLeadershipListener implements LeadershipEventListener { |
| 153 | @Override |
| 154 | public boolean isRelevant(LeadershipEvent event) { |
| 155 | return REBALANCE_MASTERSHIP.equals(event.subject().topic()); |
| 156 | } |
| 157 | |
| 158 | @Override |
| 159 | public void event(LeadershipEvent event) { |
Madan Jampani | 620f70d | 2016-01-30 22:22:47 -0800 | [diff] [blame] | 160 | processLeaderChange(event.subject().leaderNodeId()); |
Aaron Kruglikov | 2932798 | 2015-10-06 17:15:16 -0700 | [diff] [blame] | 161 | } |
| 162 | } |
Madan Jampani | 620f70d | 2016-01-30 22:22:47 -0800 | [diff] [blame] | 163 | } |