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 static com.google.common.base.Verify.verifyNotNull;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import akka.actor.typed.ActorRef;
  14 import akka.actor.typed.Behavior;
  15 import akka.actor.typed.javadsl.AbstractBehavior;
  16 import akka.actor.typed.javadsl.ActorContext;
  17 import akka.actor.typed.javadsl.Behaviors;
  18 import akka.actor.typed.javadsl.Receive;
  19 import akka.cluster.ClusterEvent;
  20 import akka.cluster.ClusterEvent.CurrentClusterState;
  21 import akka.cluster.Member;
  22 import akka.cluster.ddata.LWWRegister;
  23 import akka.cluster.ddata.LWWRegisterKey;
  24 import akka.cluster.ddata.ORMap;
  25 import akka.cluster.ddata.ORSet;
  26 import akka.cluster.ddata.SelfUniqueAddress;
  27 import akka.cluster.ddata.typed.javadsl.DistributedData;
  28 import akka.cluster.ddata.typed.javadsl.Replicator;
  29 import akka.cluster.ddata.typed.javadsl.ReplicatorMessageAdapter;
  30 import akka.cluster.typed.Cluster;
  31 import akka.cluster.typed.Subscribe;
  32 import com.google.common.collect.HashMultimap;
  33 import com.google.common.collect.ImmutableList;
  34 import com.google.common.collect.ImmutableSet;
  35 import com.google.common.collect.Multimap;
  36 import com.google.common.collect.Sets;
  37 import java.time.Duration;
  38 import java.util.ArrayList;
  39 import java.util.Collection;
  40 import java.util.HashSet;
  41 import java.util.List;
  42 import java.util.Map;
  43 import java.util.Set;
  44 import java.util.function.BiPredicate;
  45 import java.util.stream.Collectors;
  46 import java.util.stream.StreamSupport;
  47 import org.opendaylight.controller.eos.akka.owner.supervisor.command.AbstractEntityRequest;
  48 import org.opendaylight.controller.eos.akka.owner.supervisor.command.CandidatesChanged;
  49 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DataCenterDeactivated;
  50 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DeactivateDataCenter;
  51 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntitiesReply;
  52 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntitiesRequest;
  53 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityOwnerReply;
  54 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityOwnerRequest;
  55 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityReply;
  56 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityRequest;
  57 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberDownEvent;
  58 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberReachableEvent;
  59 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUnreachableEvent;
  60 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUpEvent;
  61 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerChanged;
  62 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerSupervisorCommand;
  63 import org.opendaylight.controller.eos.akka.registry.candidate.CandidateRegistry;
  64 import org.opendaylight.mdsal.binding.dom.codec.api.BindingInstanceIdentifierCodec;
  65 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
  66 import org.slf4j.Logger;
  67 import org.slf4j.LoggerFactory;
  68 import scala.collection.JavaConverters;
  69
  70 /**
  71  * Responsible for tracking candidates and assigning ownership of entities. This behavior is subscribed to the candidate
  72  * registry in distributed-data and picks entity owners based on the current cluster state and registered candidates.
  73  * On cluster up/down etc. events the owners are reassigned if possible.
  74  */
  75 public final class OwnerSupervisor extends AbstractBehavior<OwnerSupervisorCommand> {
  76
  77     private static final Logger LOG = LoggerFactory.getLogger(OwnerSupervisor.class);
  78     private static final String DATACENTER_PREFIX = "dc-";
  79
  80     private final ReplicatorMessageAdapter<OwnerSupervisorCommand, LWWRegister<String>> ownerReplicator;
  81
  82     // Our own clock implementation so we do not have to rely on synchronized clocks. This basically functions as an
  83     // increasing counter which is fine for our needs as we only ever have a single writer since t supervisor is
  84     // running in a cluster-singleton
  85     private final LWWRegister.Clock<String> clock = (currentTimestamp, value) -> currentTimestamp + 1;
  86
  87     private final Cluster cluster;
  88     private final SelfUniqueAddress node;
  89     private final String dataCenter;
  90
  91     private final Set<String> activeMembers;
  92
  93     // currently registered candidates
  94     private final Map<DOMEntity, Set<String>> currentCandidates;
  95     // current owners
  96     private final Map<DOMEntity, String> currentOwners;
  97     // reverse lookup of owner to entity
  98     private final Multimap<String, DOMEntity> ownerToEntity = HashMultimap.create();
  99
 100     // only reassign owner for those entities that lost this candidate or is not reachable
 101     private final BiPredicate<DOMEntity, String> reassignPredicate = (entity, candidate) ->
 102             !isActiveCandidate(candidate) || !isCandidateFor(entity, candidate);
 103
 104     private final BindingInstanceIdentifierCodec iidCodec;
 105
 106     private OwnerSupervisor(final ActorContext<OwnerSupervisorCommand> context,
 107                             final Map<DOMEntity, Set<String>> currentCandidates,
 108                             final Map<DOMEntity, String> currentOwners,
 109                             final BindingInstanceIdentifierCodec iidCodec) {
 110         super(context);
 111         this.iidCodec = requireNonNull(iidCodec);
 112
 113         final DistributedData distributedData = DistributedData.get(context.getSystem());
 114         final ActorRef<Replicator.Command> replicator = distributedData.replicator();
 115
 116         cluster = Cluster.get(context.getSystem());
 117         ownerReplicator = new ReplicatorMessageAdapter<>(context, replicator, Duration.ofSeconds(5));
 118         dataCenter = extractDatacenterRole(cluster.selfMember());
 119
 120         node = distributedData.selfUniqueAddress();
 121         activeMembers = getActiveMembers();
 122
 123         this.currentCandidates = currentCandidates;
 124         this.currentOwners = currentOwners;
 125
 126         for (final Map.Entry<DOMEntity, String> entry : currentOwners.entrySet()) {
 127             ownerToEntity.put(entry.getValue(), entry.getKey());
 128         }
 129
 130         // check whether we have any unreachable/missing owners
 131         reassignUnreachableOwners();
 132         assignMissingOwners();
 133
 134         final ActorRef<ClusterEvent.MemberEvent> memberEventAdapter =
 135                 context.messageAdapter(ClusterEvent.MemberEvent.class, event -> {
 136                     if (event instanceof ClusterEvent.MemberUp) {
 137                         return new MemberUpEvent(event.member().address(), event.member().getRoles());
 138                     } else {
 139                         return new MemberDownEvent(event.member().address(), event.member().getRoles());
 140                     }
 141                 });
 142         cluster.subscriptions().tell(Subscribe.create(memberEventAdapter, ClusterEvent.MemberEvent.class));
 143
 144         final ActorRef<ClusterEvent.ReachabilityEvent> reachabilityEventAdapter =
 145                 context.messageAdapter(ClusterEvent.ReachabilityEvent.class, event -> {
 146                     if (event instanceof ClusterEvent.ReachableMember) {
 147                         return new MemberReachableEvent(event.member().address(), event.member().getRoles());
 148                     } else {
 149                         return new MemberUnreachableEvent(event.member().address(), event.member().getRoles());
 150                     }
 151                 });
 152         cluster.subscriptions().tell(Subscribe.create(reachabilityEventAdapter, ClusterEvent.ReachabilityEvent.class));
 153
 154         new ReplicatorMessageAdapter<OwnerSupervisorCommand, ORMap<DOMEntity, ORSet<String>>>(context, replicator,
 155             Duration.ofSeconds(5)).subscribe(CandidateRegistry.KEY, CandidatesChanged::new);
 156
 157         LOG.debug("Owner Supervisor started");
 158     }
 159
 160     public static Behavior<OwnerSupervisorCommand> create(final Map<DOMEntity, Set<String>> currentCandidates,
 161             final Map<DOMEntity, String> currentOwners, final BindingInstanceIdentifierCodec iidCodec) {
 162         return Behaviors.setup(ctx -> new OwnerSupervisor(ctx, currentCandidates, currentOwners, iidCodec));
 163     }
 164
 165     @Override
 166     public Receive<OwnerSupervisorCommand> createReceive() {
 167         return newReceiveBuilder()
 168                 .onMessage(CandidatesChanged.class, this::onCandidatesChanged)
 169                 .onMessage(DeactivateDataCenter.class, this::onDeactivateDatacenter)
 170                 .onMessage(OwnerChanged.class, this::onOwnerChanged)
 171                 .onMessage(MemberUpEvent.class, this::onPeerUp)
 172                 .onMessage(MemberDownEvent.class, this::onPeerDown)
 173                 .onMessage(MemberReachableEvent.class, this::onPeerReachable)
 174                 .onMessage(MemberUnreachableEvent.class, this::onPeerUnreachable)
 175                 .onMessage(GetEntitiesRequest.class, this::onGetEntities)
 176                 .onMessage(GetEntityRequest.class, this::onGetEntity)
 177                 .onMessage(GetEntityOwnerRequest.class, this::onGetEntityOwner)
 178                 .build();
 179     }
 180
 181     private Behavior<OwnerSupervisorCommand> onDeactivateDatacenter(final DeactivateDataCenter command) {
 182         LOG.debug("Deactivating Owner Supervisor on {}", cluster.selfMember());
 183         command.getReplyTo().tell(DataCenterDeactivated.INSTANCE);
 184         return IdleSupervisor.create(iidCodec);
 185     }
 186
 187     private Behavior<OwnerSupervisorCommand> onOwnerChanged(final OwnerChanged command) {
 188         LOG.debug("Owner has changed for {}", command.getResponse().key());
 189         return this;
 190     }
 191
 192     private void reassignUnreachableOwners() {
 193         final Set<String> ownersToReassign = new HashSet<>();
 194         for (final String owner : ownerToEntity.keys()) {
 195             if (!activeMembers.contains(owner)) {
 196                 ownersToReassign.add(owner);
 197             }
 198         }
 199
 200         for (final String owner : ownersToReassign) {
 201             reassignCandidatesFor(owner, ImmutableList.copyOf(ownerToEntity.get(owner)), reassignPredicate);
 202         }
 203     }
 204
 205     private void assignMissingOwners() {
 206         for (final Map.Entry<DOMEntity, Set<String>> entry : currentCandidates.entrySet()) {
 207             if (!currentOwners.containsKey(entry.getKey())) {
 208                 assignOwnerFor(entry.getKey());
 209             }
 210         }
 211     }
 212
 213     private Behavior<OwnerSupervisorCommand> onCandidatesChanged(final CandidatesChanged message) {
 214         LOG.debug("onCandidatesChanged {}", message.getResponse());
 215         if (message.getResponse() instanceof Replicator.Changed) {
 216             final Replicator.Changed<ORMap<DOMEntity, ORSet<String>>> changed =
 217                     (Replicator.Changed<ORMap<DOMEntity, ORSet<String>>>) message.getResponse();
 218             processCandidateChanges(changed.get(CandidateRegistry.KEY));
 219         }
 220         return this;
 221     }
 222
 223     private void processCandidateChanges(final ORMap<DOMEntity, ORSet<String>> candidates) {
 224         final Map<DOMEntity, ORSet<String>> entries = candidates.getEntries();
 225         for (final Map.Entry<DOMEntity, ORSet<String>> entry : entries.entrySet()) {
 226             processCandidatesFor(entry.getKey(), entry.getValue());
 227         }
 228     }
 229
 230     private void processCandidatesFor(final DOMEntity entity, final ORSet<String> receivedCandidates) {
 231         LOG.debug("Processing candidates for : {}, new value: {}", entity, receivedCandidates.elements());
 232
 233         final Set<String> candidates = JavaConverters.asJava(receivedCandidates.elements());
 234         // only insert candidates if there are any to insert, otherwise we would generate unnecessary notification with
 235         // no owner
 236         if (!currentCandidates.containsKey(entity) && !candidates.isEmpty()) {
 237             LOG.debug("Candidates missing for entity: {} adding all candidates", entity);
 238             currentCandidates.put(entity, new HashSet<>(candidates));
 239
 240             LOG.debug("Current state for {} : {}", entity, currentCandidates.get(entity).toString());
 241             assignOwnerFor(entity);
 242
 243             return;
 244         }
 245
 246         final Set<String> currentlyPresent = currentCandidates.getOrDefault(entity, Set.of());
 247         final Set<String> difference = ImmutableSet.copyOf(Sets.symmetricDifference(currentlyPresent, candidates));
 248
 249         LOG.debug("currently present candidates: {}", currentlyPresent);
 250         LOG.debug("difference: {}", difference);
 251
 252         final List<String> ownersToReassign = new ArrayList<>();
 253
 254         // first add/remove candidates from entities
 255         for (final String toCheck : difference) {
 256             if (!currentlyPresent.contains(toCheck)) {
 257                 // add new candidate
 258                 LOG.debug("Adding new candidate for entity: {} : {}", entity, toCheck);
 259                 currentCandidates.get(entity).add(toCheck);
 260
 261                 if (!currentOwners.containsKey(entity)) {
 262                     // might as well assign right away when we don't have an owner
 263                     assignOwnerFor(entity);
 264                 }
 265
 266                 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
 267                 continue;
 268             }
 269
 270             if (!candidates.contains(toCheck)) {
 271                 // remove candidate
 272                 LOG.debug("Removing candidate from entity: {} - {}", entity, toCheck);
 273                 currentCandidates.get(entity).remove(toCheck);
 274                 if (ownerToEntity.containsKey(toCheck)) {
 275                     ownersToReassign.add(toCheck);
 276                 }
 277             }
 278         }
 279
 280         // then reassign those that need new owners
 281         for (final String toReassign : ownersToReassign) {
 282             reassignCandidatesFor(toReassign, ImmutableList.copyOf(ownerToEntity.get(toReassign)),
 283                     reassignPredicate);
 284         }
 285
 286         if (currentCandidates.get(entity) == null) {
 287             LOG.debug("Last candidate removed for {}", entity);
 288         } else {
 289             LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
 290         }
 291     }
 292
 293     private void reassignCandidatesFor(final String oldOwner, final Collection<DOMEntity> entities,
 294                                        final BiPredicate<DOMEntity, String> predicate) {
 295         LOG.debug("Reassigning owners for {}", entities);
 296         for (final DOMEntity entity : entities) {
 297             if (predicate.test(entity, oldOwner)) {
 298                 ownerToEntity.remove(oldOwner, entity);
 299                 assignOwnerFor(entity);
 300             }
 301         }
 302     }
 303
 304     private boolean isActiveCandidate(final String candidate) {
 305         return activeMembers.contains(candidate);
 306     }
 307
 308     private boolean isCandidateFor(final DOMEntity entity, final String candidate) {
 309         return currentCandidates.getOrDefault(entity, Set.of()).contains(candidate);
 310     }
 311
 312     private void assignOwnerFor(final DOMEntity entity) {
 313         final Set<String> candidatesForEntity = currentCandidates.get(entity);
 314         if (candidatesForEntity.isEmpty()) {
 315             LOG.debug("No candidates present for entity: {}", entity);
 316             removeOwner(entity);
 317             return;
 318         }
 319
 320         String pickedCandidate = null;
 321         for (final String candidate : candidatesForEntity) {
 322             if (activeMembers.contains(candidate)) {
 323                 pickedCandidate = candidate;
 324                 break;
 325             }
 326         }
 327         if (pickedCandidate == null) {
 328             LOG.debug("No candidate is reachable for {}, activeMembers: {}, currentCandidates: {}",
 329                     entity, activeMembers, currentCandidates.get(entity));
 330             // no candidate is reachable so only remove owner if necessary
 331             removeOwner(entity);
 332             return;
 333         }
 334         ownerToEntity.put(pickedCandidate, entity);
 335
 336         LOG.debug("Entity {} new owner: {}", entity, pickedCandidate);
 337         currentOwners.put(entity, pickedCandidate);
 338         writeNewOwner(entity, pickedCandidate);
 339     }
 340
 341     private void removeOwner(final DOMEntity entity) {
 342         if (currentOwners.containsKey(entity)) {
 343             // assign empty owner to dd, as we cannot delete data for a key since that would prevent
 344             // writes for the same key
 345             currentOwners.remove(entity);
 346
 347             writeNewOwner(entity, "");
 348         }
 349     }
 350
 351     private void writeNewOwner(final DOMEntity entity, final String candidate) {
 352         ownerReplicator.askUpdate(
 353                 askReplyTo -> new Replicator.Update<>(
 354                         new LWWRegisterKey<>(entity.toString()),
 355                         new LWWRegister<>(node.uniqueAddress(), candidate, 0),
 356                         Replicator.writeLocal(),
 357                         askReplyTo,
 358                         register -> register.withValue(node, candidate, clock)),
 359                 OwnerChanged::new);
 360     }
 361
 362     private Behavior<OwnerSupervisorCommand> onPeerUp(final MemberUpEvent event) {
 363         LOG.debug("Received MemberUp : {}", event);
 364
 365         handleReachableEvent(event.getRoles());
 366         return this;
 367     }
 368
 369     private Behavior<OwnerSupervisorCommand> onPeerReachable(final MemberReachableEvent event) {
 370         LOG.debug("Received MemberReachable : {}", event);
 371
 372         handleReachableEvent(event.getRoles());
 373         return this;
 374     }
 375
 376     private Behavior<OwnerSupervisorCommand> onGetEntities(final GetEntitiesRequest request) {
 377         request.getReplyTo().tell(new GetEntitiesReply(currentOwners, currentCandidates));
 378         return this;
 379     }
 380
 381     private Behavior<OwnerSupervisorCommand> onGetEntity(final GetEntityRequest request) {
 382         final DOMEntity entity = extractEntity(request);
 383         request.getReplyTo().tell(new GetEntityReply(currentOwners.get(entity), currentCandidates.get(entity)));
 384         return this;
 385     }
 386
 387     private Behavior<OwnerSupervisorCommand> onGetEntityOwner(final GetEntityOwnerRequest request) {
 388         request.getReplyTo().tell(new GetEntityOwnerReply(currentOwners.get(extractEntity(request))));
 389         return this;
 390     }
 391
 392     private void handleReachableEvent(final Set<String> roles) {
 393         if (roles.contains(dataCenter)) {
 394             activeMembers.add(extractRole(roles));
 395             assignMissingOwners();
 396         } else {
 397             LOG.debug("Received reachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
 398         }
 399     }
 400
 401     private Behavior<OwnerSupervisorCommand> onPeerDown(final MemberDownEvent event) {
 402         LOG.debug("Received MemberDown : {}", event);
 403
 404         handleUnreachableEvent(event.getRoles());
 405         return this;
 406     }
 407
 408     private Behavior<OwnerSupervisorCommand> onPeerUnreachable(final MemberUnreachableEvent event) {
 409         LOG.debug("Received MemberUnreachable : {}", event);
 410
 411         handleUnreachableEvent(event.getRoles());
 412         return this;
 413     }
 414
 415     private void handleUnreachableEvent(final Set<String> roles) {
 416         if (roles.contains(dataCenter)) {
 417             activeMembers.remove(extractRole(roles));
 418             reassignUnreachableOwners();
 419         } else {
 420             LOG.debug("Received unreachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
 421         }
 422     }
 423
 424     private Set<String> getActiveMembers() {
 425         final CurrentClusterState clusterState = cluster.state();
 426         final Set<String> unreachableRoles = clusterState.getUnreachable().stream()
 427             .map(OwnerSupervisor::extractRole)
 428             .collect(Collectors.toSet());
 429
 430         return StreamSupport.stream(clusterState.getMembers().spliterator(), false)
 431             // We are evaluating the set of roles for each member
 432             .map(Member::getRoles)
 433             // Filter out any members which do not share our dataCenter
 434             .filter(roles -> roles.contains(dataCenter))
 435             // Find first legal role
 436             .map(OwnerSupervisor::extractRole)
 437             // filter out unreachable roles
 438             .filter(role -> !unreachableRoles.contains(role))
 439             .collect(Collectors.toSet());
 440     }
 441
 442     private DOMEntity extractEntity(final AbstractEntityRequest<?> request) {
 443         final var name = request.getName();
 444         final var iid = name.getInstanceIdentifier();
 445         if (iid != null) {
 446             return new DOMEntity(request.getType().getValue(), iidCodec.fromBinding(iid));
 447         }
 448         final var str = verifyNotNull(name.getString(), "Unhandled entity name %s", name);
 449         return new DOMEntity(request.getType().getValue(), str);
 450     }
 451
 452     private static String extractRole(final Member member) {
 453         return extractRole(member.getRoles());
 454     }
 455
 456     private static String extractRole(final Set<String> roles) {
 457         return roles.stream().filter(role -> !role.startsWith(DATACENTER_PREFIX))
 458                 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
 459     }
 460
 461     private static String extractDatacenterRole(final Member member) {
 462         return member.getRoles().stream().filter(role -> role.startsWith(DATACENTER_PREFIX))
 463                 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
 464     }
 465 }