opendaylight/md-sal/eos-dom-akka/src/main/java/org/opendaylight/controller/eos/akka/owner/supervisor/OwnerSupervisor.java

   1 /*
   2  * Copyright (c) 2021 PANTHEON.tech, s.r.o. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.eos.akka.owner.supervisor;
   9
  10 import akka.actor.typed.ActorRef;
  11 import akka.actor.typed.Behavior;
  12 import akka.actor.typed.javadsl.AbstractBehavior;
  13 import akka.actor.typed.javadsl.ActorContext;
  14 import akka.actor.typed.javadsl.Behaviors;
  15 import akka.actor.typed.javadsl.Receive;
  16 import akka.cluster.ClusterEvent;
  17 import akka.cluster.Member;
  18 import akka.cluster.ddata.LWWRegister;
  19 import akka.cluster.ddata.LWWRegisterKey;
  20 import akka.cluster.ddata.ORMap;
  21 import akka.cluster.ddata.ORSet;
  22 import akka.cluster.ddata.SelfUniqueAddress;
  23 import akka.cluster.ddata.typed.javadsl.DistributedData;
  24 import akka.cluster.ddata.typed.javadsl.Replicator;
  25 import akka.cluster.ddata.typed.javadsl.ReplicatorMessageAdapter;
  26 import akka.cluster.typed.Cluster;
  27 import akka.cluster.typed.Subscribe;
  28 import com.google.common.collect.HashMultimap;
  29 import com.google.common.collect.ImmutableList;
  30 import com.google.common.collect.ImmutableSet;
  31 import com.google.common.collect.Multimap;
  32 import com.google.common.collect.Sets;
  33 import java.time.Duration;
  34 import java.util.ArrayList;
  35 import java.util.Collection;
  36 import java.util.Collections;
  37 import java.util.HashSet;
  38 import java.util.List;
  39 import java.util.Map;
  40 import java.util.Set;
  41 import java.util.function.BiPredicate;
  42 import java.util.stream.Collectors;
  43 import org.opendaylight.controller.eos.akka.owner.supervisor.command.CandidatesChanged;
  44 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DataCenterDeactivated;
  45 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DeactivateDataCenter;
  46 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberDownEvent;
  47 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberReachableEvent;
  48 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUnreachableEvent;
  49 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUpEvent;
  50 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerChanged;
  51 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerSupervisorCommand;
  52 import org.opendaylight.controller.eos.akka.registry.candidate.CandidateRegistry;
  53 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
  54 import org.slf4j.Logger;
  55 import org.slf4j.LoggerFactory;
  56 import scala.collection.JavaConverters;
  57
  58 /**
  59  * Responsible for tracking candidates and assigning ownership of entities. This behavior is subscribed to the candidate
  60  * registry in distributed-data and picks entity owners based on the current cluster state and registered candidates.
  61  * On cluster up/down etc. events the owners are reassigned if possible.
  62  */
  63 public final class OwnerSupervisor extends AbstractBehavior<OwnerSupervisorCommand> {
  64
  65     private static final Logger LOG = LoggerFactory.getLogger(OwnerSupervisor.class);
  66     private static final String DATACENTER_PREFIX = "dc-";
  67
  68     private final ReplicatorMessageAdapter<OwnerSupervisorCommand, LWWRegister<String>> ownerReplicator;
  69
  70     // Our own clock implementation so we do not have to rely on synchronized clocks. This basically functions as an
  71     // increasing counter which is fine for our needs as we only ever have a single writer since t supervisor is
  72     // running in a cluster-singleton
  73     private final LWWRegister.Clock<String> clock = (currentTimestamp, value) -> currentTimestamp + 1;
  74
  75     private final Cluster cluster;
  76     private final SelfUniqueAddress node;
  77     private final String dataCenter;
  78
  79     private final Set<String> activeMembers;
  80
  81     // currently registered candidates
  82     private final Map<DOMEntity, Set<String>> currentCandidates;
  83     // current owners
  84     private final Map<DOMEntity, String> currentOwners;
  85     // reverse lookup of owner to entity
  86     private final Multimap<String, DOMEntity> ownerToEntity = HashMultimap.create();
  87
  88     // only reassign owner for those entities that lost this candidate or is not reachable
  89     private final BiPredicate<DOMEntity, String> reassignPredicate = (entity, candidate) ->
  90             !isActiveCandidate(candidate) || !isCandidateFor(entity, candidate);
  91
  92     private OwnerSupervisor(final ActorContext<OwnerSupervisorCommand> context,
  93                             final Map<DOMEntity, Set<String>> currentCandidates,
  94                             final Map<DOMEntity, String> currentOwners) {
  95         super(context);
  96
  97         final DistributedData distributedData = DistributedData.get(context.getSystem());
  98         final ActorRef<Replicator.Command> replicator = distributedData.replicator();
  99
 100         cluster = Cluster.get(context.getSystem());
 101         ownerReplicator = new ReplicatorMessageAdapter<>(context, replicator, Duration.ofSeconds(5));
 102         dataCenter = extractDatacenterRole(cluster.selfMember());
 103
 104         node = distributedData.selfUniqueAddress();
 105         activeMembers = getActiveMembers();
 106
 107         this.currentCandidates = currentCandidates;
 108         this.currentOwners = currentOwners;
 109
 110         for (final Map.Entry<DOMEntity, String> entry : currentOwners.entrySet()) {
 111             ownerToEntity.put(entry.getValue(), entry.getKey());
 112         }
 113
 114         // check whether we have any unreachable/missing owners
 115         reassignUnreachableOwners();
 116         assignMissingOwners();
 117
 118         final ActorRef<ClusterEvent.MemberEvent> memberEventAdapter =
 119                 context.messageAdapter(ClusterEvent.MemberEvent.class, event -> {
 120                     if (event instanceof ClusterEvent.MemberUp) {
 121                         return new MemberUpEvent(event.member().address(), event.member().getRoles());
 122                     } else {
 123                         return new MemberDownEvent(event.member().address(), event.member().getRoles());
 124                     }
 125                 });
 126         cluster.subscriptions().tell(Subscribe.create(memberEventAdapter, ClusterEvent.MemberEvent.class));
 127
 128         final ActorRef<ClusterEvent.ReachabilityEvent> reachabilityEventAdapter =
 129                 context.messageAdapter(ClusterEvent.ReachabilityEvent.class, event -> {
 130                     if (event instanceof ClusterEvent.ReachableMember) {
 131                         return new MemberReachableEvent(event.member().address(), event.member().getRoles());
 132                     } else {
 133                         return new MemberUnreachableEvent(event.member().address(), event.member().getRoles());
 134                     }
 135                 });
 136         cluster.subscriptions().tell(Subscribe.create(reachabilityEventAdapter, ClusterEvent.ReachabilityEvent.class));
 137
 138         new ReplicatorMessageAdapter<OwnerSupervisorCommand, ORMap<DOMEntity, ORSet<String>>>(context, replicator,
 139             Duration.ofSeconds(5)).subscribe(CandidateRegistry.KEY, CandidatesChanged::new);
 140
 141         LOG.debug("Owner Supervisor started");
 142     }
 143
 144     public static Behavior<OwnerSupervisorCommand> create(final Map<DOMEntity, Set<String>> currentCandidates,
 145                                                           final Map<DOMEntity, String> currentOwners) {
 146         return Behaviors.setup(ctx -> new OwnerSupervisor(ctx, currentCandidates, currentOwners));
 147     }
 148
 149     @Override
 150     public Receive<OwnerSupervisorCommand> createReceive() {
 151         return newReceiveBuilder()
 152                 .onMessage(CandidatesChanged.class, this::onCandidatesChanged)
 153                 .onMessage(DeactivateDataCenter.class, this::onDeactivateDatacenter)
 154                 .onMessage(OwnerChanged.class, this::onOwnerChanged)
 155                 .onMessage(MemberUpEvent.class, this::onPeerUp)
 156                 .onMessage(MemberDownEvent.class, this::onPeerDown)
 157                 .onMessage(MemberReachableEvent.class, this::onPeerReachable)
 158                 .onMessage(MemberUnreachableEvent.class, this::onPeerUnreachable)
 159                 .build();
 160     }
 161
 162     private Behavior<OwnerSupervisorCommand> onDeactivateDatacenter(final DeactivateDataCenter command) {
 163         LOG.debug("Deactivating Owner Supervisor on {}", cluster.selfMember());
 164         command.getReplyTo().tell(DataCenterDeactivated.INSTANCE);
 165         return IdleSupervisor.create();
 166     }
 167
 168     private Behavior<OwnerSupervisorCommand> onOwnerChanged(final OwnerChanged command) {
 169         LOG.debug("Owner has changed for {}", command.getResponse().key());
 170         return this;
 171     }
 172
 173     private void reassignUnreachableOwners() {
 174         final Set<String> ownersToReassign = new HashSet<>();
 175         for (final String owner : ownerToEntity.keys()) {
 176             if (!activeMembers.contains(owner)) {
 177                 ownersToReassign.add(owner);
 178             }
 179         }
 180
 181         for (final String owner : ownersToReassign) {
 182             reassignCandidatesFor(owner, ImmutableList.copyOf(ownerToEntity.get(owner)), reassignPredicate);
 183         }
 184     }
 185
 186     private void assignMissingOwners() {
 187         for (final Map.Entry<DOMEntity, Set<String>> entry : currentCandidates.entrySet()) {
 188             if (!currentOwners.containsKey(entry.getKey())) {
 189                 assignOwnerFor(entry.getKey());
 190             }
 191         }
 192     }
 193
 194     private Behavior<OwnerSupervisorCommand> onCandidatesChanged(final CandidatesChanged message) {
 195         LOG.debug("onCandidatesChanged {}", message.getResponse());
 196         if (message.getResponse() instanceof Replicator.Changed) {
 197             final Replicator.Changed<ORMap<DOMEntity, ORSet<String>>> changed =
 198                     (Replicator.Changed<ORMap<DOMEntity, ORSet<String>>>) message.getResponse();
 199             processCandidateChanges(changed.get(CandidateRegistry.KEY));
 200         }
 201         return this;
 202     }
 203
 204     private void processCandidateChanges(final ORMap<DOMEntity, ORSet<String>> candidates) {
 205         final Map<DOMEntity, ORSet<String>> entries = candidates.getEntries();
 206         for (final Map.Entry<DOMEntity, ORSet<String>> entry : entries.entrySet()) {
 207             processCandidatesFor(entry.getKey(), entry.getValue());
 208         }
 209     }
 210
 211     private void processCandidatesFor(final DOMEntity entity, final ORSet<String> receivedCandidates) {
 212         LOG.debug("Processing candidates for : {}, new value: {}", entity, receivedCandidates.elements());
 213
 214         final Set<String> candidates = JavaConverters.asJava(receivedCandidates.elements());
 215         // only insert candidates if there are any to insert, otherwise we would generate unnecessary notification with
 216         // no owner
 217         if (!currentCandidates.containsKey(entity) && !candidates.isEmpty()) {
 218             LOG.debug("Candidates missing for entity: {} adding all candidates", entity);
 219             currentCandidates.put(entity, new HashSet<>(candidates));
 220
 221             LOG.debug("Current state for {} : {}", entity, currentCandidates.get(entity).toString());
 222             assignOwnerFor(entity);
 223
 224             return;
 225         }
 226
 227         final Set<String> currentlyPresent = currentCandidates.getOrDefault(entity, Collections.emptySet());
 228         final Set<String> difference = ImmutableSet.copyOf(Sets.symmetricDifference(currentlyPresent, candidates));
 229
 230         LOG.debug("currently present candidates: {}", currentlyPresent);
 231         LOG.debug("difference: {}", difference);
 232
 233         final List<String> ownersToReassign = new ArrayList<>();
 234
 235         // first add/remove candidates from entities
 236         for (final String toCheck : difference) {
 237             if (!currentlyPresent.contains(toCheck)) {
 238                 // add new candidate
 239                 LOG.debug("Adding new candidate for entity: {} : {}", entity, toCheck);
 240                 currentCandidates.get(entity).add(toCheck);
 241
 242                 if (!currentOwners.containsKey(entity)) {
 243                     // might as well assign right away when we don't have an owner
 244                     assignOwnerFor(entity);
 245                 }
 246
 247                 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
 248                 continue;
 249             }
 250
 251             if (!candidates.contains(toCheck)) {
 252                 // remove candidate
 253                 LOG.debug("Removing candidate from entity: {} - {}", entity, toCheck);
 254                 currentCandidates.get(entity).remove(toCheck);
 255                 if (ownerToEntity.containsKey(toCheck)) {
 256                     ownersToReassign.add(toCheck);
 257                 }
 258             }
 259         }
 260
 261         // then reassign those that need new owners
 262         for (final String toReassign : ownersToReassign) {
 263             reassignCandidatesFor(toReassign, ImmutableList.copyOf(ownerToEntity.get(toReassign)),
 264                     reassignPredicate);
 265         }
 266
 267         if (currentCandidates.get(entity) == null) {
 268             LOG.debug("Last candidate removed for {}", entity);
 269         } else {
 270             LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
 271         }
 272     }
 273
 274     private void reassignCandidatesFor(final String oldOwner, final Collection<DOMEntity> entities,
 275                                        final BiPredicate<DOMEntity, String> predicate) {
 276         LOG.debug("Reassigning owners for {}", entities);
 277         for (final DOMEntity entity : entities) {
 278
 279
 280             if (predicate.test(entity, oldOwner)) {
 281                 ownerToEntity.remove(oldOwner, entity);
 282                 assignOwnerFor(entity);
 283             }
 284         }
 285     }
 286
 287     private boolean isActiveCandidate(final String candidate) {
 288         return activeMembers.contains(candidate);
 289     }
 290
 291     private boolean isCandidateFor(final DOMEntity entity, final String candidate) {
 292         return currentCandidates.getOrDefault(entity, Collections.emptySet()).contains(candidate);
 293     }
 294
 295     private void assignOwnerFor(final DOMEntity entity) {
 296         final Set<String> candidatesForEntity = currentCandidates.get(entity);
 297         if (candidatesForEntity.isEmpty()) {
 298             LOG.debug("No candidates present for entity: {}", entity);
 299             removeOwner(entity);
 300             return;
 301         }
 302
 303         String pickedCandidate = null;
 304         for (final String candidate : candidatesForEntity) {
 305             if (activeMembers.contains(candidate)) {
 306                 pickedCandidate = candidate;
 307                 break;
 308             }
 309         }
 310         if (pickedCandidate == null) {
 311             LOG.debug("No candidate is reachable for {}, activeMembers: {}, currentCandidates: {}",
 312                     entity, activeMembers, currentCandidates.get(entity));
 313             // no candidate is reachable so only remove owner if necessary
 314             removeOwner(entity);
 315             return;
 316         }
 317         ownerToEntity.put(pickedCandidate, entity);
 318
 319         LOG.debug("Entity {} new owner: {}", entity, pickedCandidate);
 320         currentOwners.put(entity, pickedCandidate);
 321         writeNewOwner(entity, pickedCandidate);
 322     }
 323
 324     private void removeOwner(final DOMEntity entity) {
 325         if (currentOwners.containsKey(entity)) {
 326             // assign empty owner to dd, as we cannot delete data for a key since that would prevent
 327             // writes for the same key
 328             currentOwners.remove(entity);
 329
 330             writeNewOwner(entity, "");
 331         }
 332     }
 333
 334     private void writeNewOwner(final DOMEntity entity, final String candidate) {
 335         ownerReplicator.askUpdate(
 336                 askReplyTo -> new Replicator.Update<>(
 337                         new LWWRegisterKey<>(entity.toString()),
 338                         new LWWRegister<>(node.uniqueAddress(), candidate, 0),
 339                         Replicator.writeLocal(),
 340                         askReplyTo,
 341                         register -> register.withValue(node, candidate, clock)),
 342                 OwnerChanged::new);
 343     }
 344
 345     private Behavior<OwnerSupervisorCommand> onPeerUp(final MemberUpEvent event) {
 346         LOG.debug("Received MemberUp : {}", event);
 347
 348         handleReachableEvent(event.getRoles());
 349         return this;
 350     }
 351
 352     private Behavior<OwnerSupervisorCommand> onPeerReachable(final MemberReachableEvent event) {
 353         LOG.debug("Received MemberReachable : {}", event);
 354
 355         handleReachableEvent(event.getRoles());
 356         return this;
 357     }
 358
 359     private void handleReachableEvent(final Set<String> roles) {
 360         if (roles.contains(dataCenter)) {
 361             activeMembers.add(extractRole(roles));
 362             assignMissingOwners();
 363         } else {
 364             LOG.debug("Received reachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
 365         }
 366     }
 367
 368     private Behavior<OwnerSupervisorCommand> onPeerDown(final MemberDownEvent event) {
 369         LOG.debug("Received MemberDown : {}", event);
 370
 371         handleUnreachableEvent(event.getRoles());
 372         return this;
 373     }
 374
 375     private Behavior<OwnerSupervisorCommand> onPeerUnreachable(final MemberUnreachableEvent event) {
 376         LOG.debug("Received MemberUnreachable : {}", event);
 377
 378         handleUnreachableEvent(event.getRoles());
 379         return this;
 380     }
 381
 382     private void handleUnreachableEvent(final Set<String> roles) {
 383         if (roles.contains(dataCenter)) {
 384             activeMembers.remove(extractRole(roles));
 385             reassignUnreachableOwners();
 386         } else {
 387             LOG.debug("Received unreachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
 388         }
 389     }
 390
 391     private Set<String> getActiveMembers() {
 392         final Set<String> members = new HashSet<>();
 393         cluster.state().getMembers().forEach(member -> members.add(extractRole(member)));
 394         // filter out unreachable
 395         members.removeAll(cluster.state().getUnreachable().stream()
 396                 .map(OwnerSupervisor::extractRole)
 397                 .collect(Collectors.toSet()));
 398
 399         // filter out members not from our datacenter
 400         cluster.state().getMembers().forEach(member -> {
 401             if (!member.roles().contains(dataCenter)) {
 402                 members.remove(extractRole(member));
 403             }
 404         });
 405
 406         return members;
 407     }
 408
 409     private static String extractRole(final Member member) {
 410         return extractRole(member.getRoles());
 411     }
 412
 413     private static String extractRole(final Set<String> roles) {
 414         return roles.stream().filter(role -> !role.startsWith(DATACENTER_PREFIX))
 415                 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
 416     }
 417
 418     private String extractDatacenterRole(final Member member) {
 419         return member.getRoles().stream().filter(role -> role.startsWith(DATACENTER_PREFIX))
 420                 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
 421     }
 422 }