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.AbstractEntityRequest;
  44 import org.opendaylight.controller.eos.akka.owner.supervisor.command.CandidatesChanged;
  45 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DataCenterDeactivated;
  46 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DeactivateDataCenter;
  47 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntitiesReply;
  48 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntitiesRequest;
  49 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityOwnerReply;
  50 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityOwnerRequest;
  51 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityReply;
  52 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityRequest;
  53 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberDownEvent;
  54 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberReachableEvent;
  55 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUnreachableEvent;
  56 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUpEvent;
  57 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerChanged;
  58 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerSupervisorCommand;
  59 import org.opendaylight.controller.eos.akka.registry.candidate.CandidateRegistry;
  60 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
  61 import org.slf4j.Logger;
  62 import org.slf4j.LoggerFactory;
  63 import scala.collection.JavaConverters;
  64
  65 /**
  66  * Responsible for tracking candidates and assigning ownership of entities. This behavior is subscribed to the candidate
  67  * registry in distributed-data and picks entity owners based on the current cluster state and registered candidates.
  68  * On cluster up/down etc. events the owners are reassigned if possible.
  69  */
  70 public final class OwnerSupervisor extends AbstractBehavior<OwnerSupervisorCommand> {
  71
  72     private static final Logger LOG = LoggerFactory.getLogger(OwnerSupervisor.class);
  73     private static final String DATACENTER_PREFIX = "dc-";
  74
  75     private final ReplicatorMessageAdapter<OwnerSupervisorCommand, LWWRegister<String>> ownerReplicator;
  76
  77     // Our own clock implementation so we do not have to rely on synchronized clocks. This basically functions as an
  78     // increasing counter which is fine for our needs as we only ever have a single writer since t supervisor is
  79     // running in a cluster-singleton
  80     private final LWWRegister.Clock<String> clock = (currentTimestamp, value) -> currentTimestamp + 1;
  81
  82     private final Cluster cluster;
  83     private final SelfUniqueAddress node;
  84     private final String dataCenter;
  85
  86     private final Set<String> activeMembers;
  87
  88     // currently registered candidates
  89     private final Map<DOMEntity, Set<String>> currentCandidates;
  90     // current owners
  91     private final Map<DOMEntity, String> currentOwners;
  92     // reverse lookup of owner to entity
  93     private final Multimap<String, DOMEntity> ownerToEntity = HashMultimap.create();
  94
  95     // only reassign owner for those entities that lost this candidate or is not reachable
  96     private final BiPredicate<DOMEntity, String> reassignPredicate = (entity, candidate) ->
  97             !isActiveCandidate(candidate) || !isCandidateFor(entity, candidate);
  98
  99     private OwnerSupervisor(final ActorContext<OwnerSupervisorCommand> context,
 100                             final Map<DOMEntity, Set<String>> currentCandidates,
 101                             final Map<DOMEntity, String> currentOwners) {
 102         super(context);
 103
 104         final DistributedData distributedData = DistributedData.get(context.getSystem());
 105         final ActorRef<Replicator.Command> replicator = distributedData.replicator();
 106
 107         cluster = Cluster.get(context.getSystem());
 108         ownerReplicator = new ReplicatorMessageAdapter<>(context, replicator, Duration.ofSeconds(5));
 109         dataCenter = extractDatacenterRole(cluster.selfMember());
 110
 111         node = distributedData.selfUniqueAddress();
 112         activeMembers = getActiveMembers();
 113
 114         this.currentCandidates = currentCandidates;
 115         this.currentOwners = currentOwners;
 116
 117         for (final Map.Entry<DOMEntity, String> entry : currentOwners.entrySet()) {
 118             ownerToEntity.put(entry.getValue(), entry.getKey());
 119         }
 120
 121         // check whether we have any unreachable/missing owners
 122         reassignUnreachableOwners();
 123         assignMissingOwners();
 124
 125         final ActorRef<ClusterEvent.MemberEvent> memberEventAdapter =
 126                 context.messageAdapter(ClusterEvent.MemberEvent.class, event -> {
 127                     if (event instanceof ClusterEvent.MemberUp) {
 128                         return new MemberUpEvent(event.member().address(), event.member().getRoles());
 129                     } else {
 130                         return new MemberDownEvent(event.member().address(), event.member().getRoles());
 131                     }
 132                 });
 133         cluster.subscriptions().tell(Subscribe.create(memberEventAdapter, ClusterEvent.MemberEvent.class));
 134
 135         final ActorRef<ClusterEvent.ReachabilityEvent> reachabilityEventAdapter =
 136                 context.messageAdapter(ClusterEvent.ReachabilityEvent.class, event -> {
 137                     if (event instanceof ClusterEvent.ReachableMember) {
 138                         return new MemberReachableEvent(event.member().address(), event.member().getRoles());
 139                     } else {
 140                         return new MemberUnreachableEvent(event.member().address(), event.member().getRoles());
 141                     }
 142                 });
 143         cluster.subscriptions().tell(Subscribe.create(reachabilityEventAdapter, ClusterEvent.ReachabilityEvent.class));
 144
 145         new ReplicatorMessageAdapter<OwnerSupervisorCommand, ORMap<DOMEntity, ORSet<String>>>(context, replicator,
 146             Duration.ofSeconds(5)).subscribe(CandidateRegistry.KEY, CandidatesChanged::new);
 147
 148         LOG.debug("Owner Supervisor started");
 149     }
 150
 151     public static Behavior<OwnerSupervisorCommand> create(final Map<DOMEntity, Set<String>> currentCandidates,
 152                                                           final Map<DOMEntity, String> currentOwners) {
 153         return Behaviors.setup(ctx -> new OwnerSupervisor(ctx, currentCandidates, currentOwners));
 154     }
 155
 156     @Override
 157     public Receive<OwnerSupervisorCommand> createReceive() {
 158         return newReceiveBuilder()
 159                 .onMessage(CandidatesChanged.class, this::onCandidatesChanged)
 160                 .onMessage(DeactivateDataCenter.class, this::onDeactivateDatacenter)
 161                 .onMessage(OwnerChanged.class, this::onOwnerChanged)
 162                 .onMessage(MemberUpEvent.class, this::onPeerUp)
 163                 .onMessage(MemberDownEvent.class, this::onPeerDown)
 164                 .onMessage(MemberReachableEvent.class, this::onPeerReachable)
 165                 .onMessage(MemberUnreachableEvent.class, this::onPeerUnreachable)
 166                 .onMessage(GetEntitiesRequest.class, this::onGetEntities)
 167                 .onMessage(GetEntityRequest.class, this::onGetEntity)
 168                 .onMessage(GetEntityOwnerRequest.class, this::onGetEntityOwner)
 169                 .build();
 170     }
 171
 172     private Behavior<OwnerSupervisorCommand> onDeactivateDatacenter(final DeactivateDataCenter command) {
 173         LOG.debug("Deactivating Owner Supervisor on {}", cluster.selfMember());
 174         command.getReplyTo().tell(DataCenterDeactivated.INSTANCE);
 175         return IdleSupervisor.create();
 176     }
 177
 178     private Behavior<OwnerSupervisorCommand> onOwnerChanged(final OwnerChanged command) {
 179         LOG.debug("Owner has changed for {}", command.getResponse().key());
 180         return this;
 181     }
 182
 183     private void reassignUnreachableOwners() {
 184         final Set<String> ownersToReassign = new HashSet<>();
 185         for (final String owner : ownerToEntity.keys()) {
 186             if (!activeMembers.contains(owner)) {
 187                 ownersToReassign.add(owner);
 188             }
 189         }
 190
 191         for (final String owner : ownersToReassign) {
 192             reassignCandidatesFor(owner, ImmutableList.copyOf(ownerToEntity.get(owner)), reassignPredicate);
 193         }
 194     }
 195
 196     private void assignMissingOwners() {
 197         for (final Map.Entry<DOMEntity, Set<String>> entry : currentCandidates.entrySet()) {
 198             if (!currentOwners.containsKey(entry.getKey())) {
 199                 assignOwnerFor(entry.getKey());
 200             }
 201         }
 202     }
 203
 204     private Behavior<OwnerSupervisorCommand> onCandidatesChanged(final CandidatesChanged message) {
 205         LOG.debug("onCandidatesChanged {}", message.getResponse());
 206         if (message.getResponse() instanceof Replicator.Changed) {
 207             final Replicator.Changed<ORMap<DOMEntity, ORSet<String>>> changed =
 208                     (Replicator.Changed<ORMap<DOMEntity, ORSet<String>>>) message.getResponse();
 209             processCandidateChanges(changed.get(CandidateRegistry.KEY));
 210         }
 211         return this;
 212     }
 213
 214     private void processCandidateChanges(final ORMap<DOMEntity, ORSet<String>> candidates) {
 215         final Map<DOMEntity, ORSet<String>> entries = candidates.getEntries();
 216         for (final Map.Entry<DOMEntity, ORSet<String>> entry : entries.entrySet()) {
 217             processCandidatesFor(entry.getKey(), entry.getValue());
 218         }
 219     }
 220
 221     private void processCandidatesFor(final DOMEntity entity, final ORSet<String> receivedCandidates) {
 222         LOG.debug("Processing candidates for : {}, new value: {}", entity, receivedCandidates.elements());
 223
 224         final Set<String> candidates = JavaConverters.asJava(receivedCandidates.elements());
 225         // only insert candidates if there are any to insert, otherwise we would generate unnecessary notification with
 226         // no owner
 227         if (!currentCandidates.containsKey(entity) && !candidates.isEmpty()) {
 228             LOG.debug("Candidates missing for entity: {} adding all candidates", entity);
 229             currentCandidates.put(entity, new HashSet<>(candidates));
 230
 231             LOG.debug("Current state for {} : {}", entity, currentCandidates.get(entity).toString());
 232             assignOwnerFor(entity);
 233
 234             return;
 235         }
 236
 237         final Set<String> currentlyPresent = currentCandidates.getOrDefault(entity, Collections.emptySet());
 238         final Set<String> difference = ImmutableSet.copyOf(Sets.symmetricDifference(currentlyPresent, candidates));
 239
 240         LOG.debug("currently present candidates: {}", currentlyPresent);
 241         LOG.debug("difference: {}", difference);
 242
 243         final List<String> ownersToReassign = new ArrayList<>();
 244
 245         // first add/remove candidates from entities
 246         for (final String toCheck : difference) {
 247             if (!currentlyPresent.contains(toCheck)) {
 248                 // add new candidate
 249                 LOG.debug("Adding new candidate for entity: {} : {}", entity, toCheck);
 250                 currentCandidates.get(entity).add(toCheck);
 251
 252                 if (!currentOwners.containsKey(entity)) {
 253                     // might as well assign right away when we don't have an owner
 254                     assignOwnerFor(entity);
 255                 }
 256
 257                 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
 258                 continue;
 259             }
 260
 261             if (!candidates.contains(toCheck)) {
 262                 // remove candidate
 263                 LOG.debug("Removing candidate from entity: {} - {}", entity, toCheck);
 264                 currentCandidates.get(entity).remove(toCheck);
 265                 if (ownerToEntity.containsKey(toCheck)) {
 266                     ownersToReassign.add(toCheck);
 267                 }
 268             }
 269         }
 270
 271         // then reassign those that need new owners
 272         for (final String toReassign : ownersToReassign) {
 273             reassignCandidatesFor(toReassign, ImmutableList.copyOf(ownerToEntity.get(toReassign)),
 274                     reassignPredicate);
 275         }
 276
 277         if (currentCandidates.get(entity) == null) {
 278             LOG.debug("Last candidate removed for {}", entity);
 279         } else {
 280             LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
 281         }
 282     }
 283
 284     private void reassignCandidatesFor(final String oldOwner, final Collection<DOMEntity> entities,
 285                                        final BiPredicate<DOMEntity, String> predicate) {
 286         LOG.debug("Reassigning owners for {}", entities);
 287         for (final DOMEntity entity : entities) {
 288             if (predicate.test(entity, oldOwner)) {
 289                 ownerToEntity.remove(oldOwner, entity);
 290                 assignOwnerFor(entity);
 291             }
 292         }
 293     }
 294
 295     private boolean isActiveCandidate(final String candidate) {
 296         return activeMembers.contains(candidate);
 297     }
 298
 299     private boolean isCandidateFor(final DOMEntity entity, final String candidate) {
 300         return currentCandidates.getOrDefault(entity, Collections.emptySet()).contains(candidate);
 301     }
 302
 303     private void assignOwnerFor(final DOMEntity entity) {
 304         final Set<String> candidatesForEntity = currentCandidates.get(entity);
 305         if (candidatesForEntity.isEmpty()) {
 306             LOG.debug("No candidates present for entity: {}", entity);
 307             removeOwner(entity);
 308             return;
 309         }
 310
 311         String pickedCandidate = null;
 312         for (final String candidate : candidatesForEntity) {
 313             if (activeMembers.contains(candidate)) {
 314                 pickedCandidate = candidate;
 315                 break;
 316             }
 317         }
 318         if (pickedCandidate == null) {
 319             LOG.debug("No candidate is reachable for {}, activeMembers: {}, currentCandidates: {}",
 320                     entity, activeMembers, currentCandidates.get(entity));
 321             // no candidate is reachable so only remove owner if necessary
 322             removeOwner(entity);
 323             return;
 324         }
 325         ownerToEntity.put(pickedCandidate, entity);
 326
 327         LOG.debug("Entity {} new owner: {}", entity, pickedCandidate);
 328         currentOwners.put(entity, pickedCandidate);
 329         writeNewOwner(entity, pickedCandidate);
 330     }
 331
 332     private void removeOwner(final DOMEntity entity) {
 333         if (currentOwners.containsKey(entity)) {
 334             // assign empty owner to dd, as we cannot delete data for a key since that would prevent
 335             // writes for the same key
 336             currentOwners.remove(entity);
 337
 338             writeNewOwner(entity, "");
 339         }
 340     }
 341
 342     private void writeNewOwner(final DOMEntity entity, final String candidate) {
 343         ownerReplicator.askUpdate(
 344                 askReplyTo -> new Replicator.Update<>(
 345                         new LWWRegisterKey<>(entity.toString()),
 346                         new LWWRegister<>(node.uniqueAddress(), candidate, 0),
 347                         Replicator.writeLocal(),
 348                         askReplyTo,
 349                         register -> register.withValue(node, candidate, clock)),
 350                 OwnerChanged::new);
 351     }
 352
 353     private Behavior<OwnerSupervisorCommand> onPeerUp(final MemberUpEvent event) {
 354         LOG.debug("Received MemberUp : {}", event);
 355
 356         handleReachableEvent(event.getRoles());
 357         return this;
 358     }
 359
 360     private Behavior<OwnerSupervisorCommand> onPeerReachable(final MemberReachableEvent event) {
 361         LOG.debug("Received MemberReachable : {}", event);
 362
 363         handleReachableEvent(event.getRoles());
 364         return this;
 365     }
 366
 367     private Behavior<OwnerSupervisorCommand> onGetEntities(final GetEntitiesRequest request) {
 368         request.getReplyTo().tell(new GetEntitiesReply(currentOwners, currentCandidates));
 369         return this;
 370     }
 371
 372     private Behavior<OwnerSupervisorCommand> onGetEntity(final GetEntityRequest request) {
 373         final DOMEntity entity = extractEntity(request);
 374         request.getReplyTo().tell(new GetEntityReply(currentOwners.get(entity), currentCandidates.get(entity)));
 375         return this;
 376     }
 377
 378     private Behavior<OwnerSupervisorCommand> onGetEntityOwner(final GetEntityOwnerRequest request) {
 379         request.getReplyTo().tell(new GetEntityOwnerReply(currentOwners.get(extractEntity(request))));
 380         return this;
 381     }
 382
 383     private void handleReachableEvent(final Set<String> roles) {
 384         if (roles.contains(dataCenter)) {
 385             activeMembers.add(extractRole(roles));
 386             assignMissingOwners();
 387         } else {
 388             LOG.debug("Received reachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
 389         }
 390     }
 391
 392     private Behavior<OwnerSupervisorCommand> onPeerDown(final MemberDownEvent event) {
 393         LOG.debug("Received MemberDown : {}", event);
 394
 395         handleUnreachableEvent(event.getRoles());
 396         return this;
 397     }
 398
 399     private Behavior<OwnerSupervisorCommand> onPeerUnreachable(final MemberUnreachableEvent event) {
 400         LOG.debug("Received MemberUnreachable : {}", event);
 401
 402         handleUnreachableEvent(event.getRoles());
 403         return this;
 404     }
 405
 406     private void handleUnreachableEvent(final Set<String> roles) {
 407         if (roles.contains(dataCenter)) {
 408             activeMembers.remove(extractRole(roles));
 409             reassignUnreachableOwners();
 410         } else {
 411             LOG.debug("Received unreachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
 412         }
 413     }
 414
 415     private Set<String> getActiveMembers() {
 416         final Set<String> members = new HashSet<>();
 417         cluster.state().getMembers().forEach(member -> members.add(extractRole(member)));
 418         // filter out unreachable
 419         members.removeAll(cluster.state().getUnreachable().stream()
 420                 .map(OwnerSupervisor::extractRole)
 421                 .collect(Collectors.toSet()));
 422
 423         // filter out members not from our datacenter
 424         cluster.state().getMembers().forEach(member -> {
 425             if (!member.roles().contains(dataCenter)) {
 426                 members.remove(extractRole(member));
 427             }
 428         });
 429
 430         return members;
 431     }
 432
 433     private static DOMEntity extractEntity(final AbstractEntityRequest<?> request) {
 434         return new DOMEntity(request.getType().getValue(), request.getName().getValue());
 435     }
 436
 437     private static String extractRole(final Member member) {
 438         return extractRole(member.getRoles());
 439     }
 440
 441     private static String extractRole(final Set<String> roles) {
 442         return roles.stream().filter(role -> !role.startsWith(DATACENTER_PREFIX))
 443                 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
 444     }
 445
 446     private String extractDatacenterRole(final Member member) {
 447         return member.getRoles().stream().filter(role -> role.startsWith(DATACENTER_PREFIX))
 448                 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
 449     }
 450 }