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 akka.pattern.StatusReply;
  33 import com.google.common.collect.HashMultimap;
  34 import com.google.common.collect.ImmutableList;
  35 import com.google.common.collect.ImmutableSet;
  36 import com.google.common.collect.Multimap;
  37 import com.google.common.collect.Sets;
  38 import java.time.Duration;
  39 import java.util.ArrayList;
  40 import java.util.Collection;
  41 import java.util.HashSet;
  42 import java.util.List;
  43 import java.util.Map;
  44 import java.util.Set;
  45 import java.util.function.BiPredicate;
  46 import java.util.stream.Collectors;
  47 import java.util.stream.StreamSupport;
  48 import org.opendaylight.controller.eos.akka.owner.supervisor.command.AbstractEntityRequest;
  49 import org.opendaylight.controller.eos.akka.owner.supervisor.command.CandidatesChanged;
  50 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DataCenterDeactivated;
  51 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DeactivateDataCenter;
  52 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntitiesBackendReply;
  53 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntitiesBackendRequest;
  54 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityBackendReply;
  55 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityBackendRequest;
  56 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityOwnerBackendReply;
  57 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityOwnerBackendRequest;
  58 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberDownEvent;
  59 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberReachableEvent;
  60 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUnreachableEvent;
  61 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUpEvent;
  62 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerChanged;
  63 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerSupervisorCommand;
  64 import org.opendaylight.controller.eos.akka.registry.candidate.CandidateRegistry;
  65 import org.opendaylight.mdsal.binding.dom.codec.api.BindingInstanceIdentifierCodec;
  66 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
  67 import org.slf4j.Logger;
  68 import org.slf4j.LoggerFactory;
  69 import scala.collection.JavaConverters;
  70
  71 /**
  72  * Responsible for tracking candidates and assigning ownership of entities. This behavior is subscribed to the candidate
  73  * registry in distributed-data and picks entity owners based on the current cluster state and registered candidates.
  74  * On cluster up/down etc. events the owners are reassigned if possible.
  75  */
  76 public final class OwnerSupervisor extends AbstractBehavior<OwnerSupervisorCommand> {
  77
  78     private static final Logger LOG = LoggerFactory.getLogger(OwnerSupervisor.class);
  79     private static final String DATACENTER_PREFIX = "dc-";
  80
  81     private final ReplicatorMessageAdapter<OwnerSupervisorCommand, LWWRegister<String>> ownerReplicator;
  82
  83     // Our own clock implementation so we do not have to rely on synchronized clocks. This basically functions as an
  84     // increasing counter which is fine for our needs as we only ever have a single writer since t supervisor is
  85     // running in a cluster-singleton
  86     private final LWWRegister.Clock<String> clock = (currentTimestamp, value) -> currentTimestamp + 1;
  87
  88     private final Cluster cluster;
  89     private final SelfUniqueAddress node;
  90     private final String dataCenter;
  91
  92     private final Set<String> activeMembers;
  93
  94     // currently registered candidates
  95     private final Map<DOMEntity, Set<String>> currentCandidates;
  96     // current owners
  97     private final Map<DOMEntity, String> currentOwners;
  98     // reverse lookup of owner to entity
  99     private final Multimap<String, DOMEntity> ownerToEntity = HashMultimap.create();
 100
 101     // only reassign owner for those entities that lost this candidate or is not reachable
 102     private final BiPredicate<DOMEntity, String> reassignPredicate = (entity, candidate) ->
 103             !isActiveCandidate(candidate) || !isCandidateFor(entity, candidate);
 104
 105     private final BindingInstanceIdentifierCodec iidCodec;
 106
 107     private OwnerSupervisor(final ActorContext<OwnerSupervisorCommand> context,
 108                             final Map<DOMEntity, Set<String>> currentCandidates,
 109                             final Map<DOMEntity, String> currentOwners,
 110                             final BindingInstanceIdentifierCodec iidCodec) {
 111         super(context);
 112         this.iidCodec = requireNonNull(iidCodec);
 113
 114         final DistributedData distributedData = DistributedData.get(context.getSystem());
 115         final ActorRef<Replicator.Command> replicator = distributedData.replicator();
 116
 117         cluster = Cluster.get(context.getSystem());
 118         ownerReplicator = new ReplicatorMessageAdapter<>(context, replicator, Duration.ofSeconds(5));
 119         dataCenter = extractDatacenterRole(cluster.selfMember());
 120
 121         node = distributedData.selfUniqueAddress();
 122         activeMembers = getActiveMembers();
 123
 124         this.currentCandidates = currentCandidates;
 125         this.currentOwners = currentOwners;
 126
 127         for (final Map.Entry<DOMEntity, String> entry : currentOwners.entrySet()) {
 128             ownerToEntity.put(entry.getValue(), entry.getKey());
 129         }
 130
 131         // check whether we have any unreachable/missing owners
 132         reassignUnreachableOwners();
 133         assignMissingOwners();
 134
 135         final ActorRef<ClusterEvent.MemberEvent> memberEventAdapter =
 136                 context.messageAdapter(ClusterEvent.MemberEvent.class, event -> {
 137                     if (event instanceof ClusterEvent.MemberUp) {
 138                         return new MemberUpEvent(event.member().address(), event.member().getRoles());
 139                     } else {
 140                         return new MemberDownEvent(event.member().address(), event.member().getRoles());
 141                     }
 142                 });
 143         cluster.subscriptions().tell(Subscribe.create(memberEventAdapter, ClusterEvent.MemberEvent.class));
 144
 145         final ActorRef<ClusterEvent.ReachabilityEvent> reachabilityEventAdapter =
 146                 context.messageAdapter(ClusterEvent.ReachabilityEvent.class, event -> {
 147                     if (event instanceof ClusterEvent.ReachableMember) {
 148                         return new MemberReachableEvent(event.member().address(), event.member().getRoles());
 149                     } else {
 150                         return new MemberUnreachableEvent(event.member().address(), event.member().getRoles());
 151                     }
 152                 });
 153         cluster.subscriptions().tell(Subscribe.create(reachabilityEventAdapter, ClusterEvent.ReachabilityEvent.class));
 154
 155         new ReplicatorMessageAdapter<OwnerSupervisorCommand, ORMap<DOMEntity, ORSet<String>>>(context, replicator,
 156             Duration.ofSeconds(5)).subscribe(CandidateRegistry.KEY, CandidatesChanged::new);
 157
 158         LOG.debug("Owner Supervisor started");
 159     }
 160
 161     public static Behavior<OwnerSupervisorCommand> create(final Map<DOMEntity, Set<String>> currentCandidates,
 162             final Map<DOMEntity, String> currentOwners, final BindingInstanceIdentifierCodec iidCodec) {
 163         return Behaviors.setup(ctx -> new OwnerSupervisor(ctx, currentCandidates, currentOwners, iidCodec));
 164     }
 165
 166     @Override
 167     public Receive<OwnerSupervisorCommand> createReceive() {
 168         return newReceiveBuilder()
 169                 .onMessage(CandidatesChanged.class, this::onCandidatesChanged)
 170                 .onMessage(DeactivateDataCenter.class, this::onDeactivateDatacenter)
 171                 .onMessage(OwnerChanged.class, this::onOwnerChanged)
 172                 .onMessage(MemberUpEvent.class, this::onPeerUp)
 173                 .onMessage(MemberDownEvent.class, this::onPeerDown)
 174                 .onMessage(MemberReachableEvent.class, this::onPeerReachable)
 175                 .onMessage(MemberUnreachableEvent.class, this::onPeerUnreachable)
 176                 .onMessage(GetEntitiesBackendRequest.class, this::onGetEntities)
 177                 .onMessage(GetEntityBackendRequest.class, this::onGetEntity)
 178                 .onMessage(GetEntityOwnerBackendRequest.class, this::onGetEntityOwner)
 179                 .build();
 180     }
 181
 182     private Behavior<OwnerSupervisorCommand> onDeactivateDatacenter(final DeactivateDataCenter command) {
 183         LOG.debug("Deactivating Owner Supervisor on {}", cluster.selfMember());
 184         command.getReplyTo().tell(DataCenterDeactivated.INSTANCE);
 185         return IdleSupervisor.create(iidCodec);
 186     }
 187
 188     private Behavior<OwnerSupervisorCommand> onOwnerChanged(final OwnerChanged command) {
 189         LOG.debug("Owner has changed for {}", command.getResponse().key());
 190         return this;
 191     }
 192
 193     private void reassignUnreachableOwners() {
 194         final Set<String> ownersToReassign = new HashSet<>();
 195         for (final String owner : ownerToEntity.keys()) {
 196             if (!activeMembers.contains(owner)) {
 197                 ownersToReassign.add(owner);
 198             }
 199         }
 200
 201         for (final String owner : ownersToReassign) {
 202             reassignCandidatesFor(owner, ImmutableList.copyOf(ownerToEntity.get(owner)), reassignPredicate);
 203         }
 204     }
 205
 206     private void assignMissingOwners() {
 207         for (final Map.Entry<DOMEntity, Set<String>> entry : currentCandidates.entrySet()) {
 208             if (!currentOwners.containsKey(entry.getKey())) {
 209                 assignOwnerFor(entry.getKey());
 210             }
 211         }
 212     }
 213
 214     private Behavior<OwnerSupervisorCommand> onCandidatesChanged(final CandidatesChanged message) {
 215         LOG.debug("onCandidatesChanged {}", message.getResponse());
 216         if (message.getResponse() instanceof Replicator.Changed) {
 217             final Replicator.Changed<ORMap<DOMEntity, ORSet<String>>> changed =
 218                     (Replicator.Changed<ORMap<DOMEntity, ORSet<String>>>) message.getResponse();
 219             processCandidateChanges(changed.get(CandidateRegistry.KEY));
 220         }
 221         return this;
 222     }
 223
 224     private void processCandidateChanges(final ORMap<DOMEntity, ORSet<String>> candidates) {
 225         final Map<DOMEntity, ORSet<String>> entries = candidates.getEntries();
 226         for (final Map.Entry<DOMEntity, ORSet<String>> entry : entries.entrySet()) {
 227             processCandidatesFor(entry.getKey(), entry.getValue());
 228         }
 229     }
 230
 231     private void processCandidatesFor(final DOMEntity entity, final ORSet<String> receivedCandidates) {
 232         LOG.debug("Processing candidates for : {}, new value: {}", entity, receivedCandidates.elements());
 233
 234         final Set<String> candidates = JavaConverters.asJava(receivedCandidates.elements());
 235         // only insert candidates if there are any to insert, otherwise we would generate unnecessary notification with
 236         // no owner
 237         if (!currentCandidates.containsKey(entity) && !candidates.isEmpty()) {
 238             LOG.debug("Candidates missing for entity: {} adding all candidates", entity);
 239             currentCandidates.put(entity, new HashSet<>(candidates));
 240
 241             LOG.debug("Current state for {} : {}", entity, currentCandidates.get(entity).toString());
 242             assignOwnerFor(entity);
 243
 244             return;
 245         }
 246
 247         final Set<String> currentlyPresent = currentCandidates.getOrDefault(entity, Set.of());
 248         final Set<String> difference = ImmutableSet.copyOf(Sets.symmetricDifference(currentlyPresent, candidates));
 249
 250         LOG.debug("currently present candidates: {}", currentlyPresent);
 251         LOG.debug("difference: {}", difference);
 252
 253         final List<String> ownersToReassign = new ArrayList<>();
 254
 255         // first add/remove candidates from entities
 256         for (final String toCheck : difference) {
 257             if (!currentlyPresent.contains(toCheck)) {
 258                 // add new candidate
 259                 LOG.debug("Adding new candidate for entity: {} : {}", entity, toCheck);
 260                 currentCandidates.get(entity).add(toCheck);
 261
 262                 if (!currentOwners.containsKey(entity)) {
 263                     // might as well assign right away when we don't have an owner
 264                     assignOwnerFor(entity);
 265                 }
 266
 267                 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
 268                 continue;
 269             }
 270
 271             if (!candidates.contains(toCheck)) {
 272                 // remove candidate
 273                 LOG.debug("Removing candidate from entity: {} - {}", entity, toCheck);
 274                 currentCandidates.get(entity).remove(toCheck);
 275                 if (ownerToEntity.containsKey(toCheck)) {
 276                     ownersToReassign.add(toCheck);
 277                 }
 278             }
 279         }
 280
 281         // then reassign those that need new owners
 282         for (final String toReassign : ownersToReassign) {
 283             reassignCandidatesFor(toReassign, ImmutableList.copyOf(ownerToEntity.get(toReassign)),
 284                     reassignPredicate);
 285         }
 286
 287         if (currentCandidates.get(entity) == null) {
 288             LOG.debug("Last candidate removed for {}", entity);
 289         } else {
 290             LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
 291         }
 292     }
 293
 294     private void reassignCandidatesFor(final String oldOwner, final Collection<DOMEntity> entities,
 295                                        final BiPredicate<DOMEntity, String> predicate) {
 296         LOG.debug("Reassigning owners for {}", entities);
 297         for (final DOMEntity entity : entities) {
 298             if (predicate.test(entity, oldOwner)) {
 299                 ownerToEntity.remove(oldOwner, entity);
 300                 assignOwnerFor(entity);
 301             }
 302         }
 303     }
 304
 305     private boolean isActiveCandidate(final String candidate) {
 306         return activeMembers.contains(candidate);
 307     }
 308
 309     private boolean isCandidateFor(final DOMEntity entity, final String candidate) {
 310         return currentCandidates.getOrDefault(entity, Set.of()).contains(candidate);
 311     }
 312
 313     private void assignOwnerFor(final DOMEntity entity) {
 314         final Set<String> candidatesForEntity = currentCandidates.get(entity);
 315         if (candidatesForEntity.isEmpty()) {
 316             LOG.debug("No candidates present for entity: {}", entity);
 317             removeOwner(entity);
 318             return;
 319         }
 320
 321         String pickedCandidate = null;
 322         for (final String candidate : candidatesForEntity) {
 323             if (activeMembers.contains(candidate)) {
 324                 pickedCandidate = candidate;
 325                 break;
 326             }
 327         }
 328         if (pickedCandidate == null) {
 329             LOG.debug("No candidate is reachable for {}, activeMembers: {}, currentCandidates: {}",
 330                     entity, activeMembers, currentCandidates.get(entity));
 331             // no candidate is reachable so only remove owner if necessary
 332             removeOwner(entity);
 333             return;
 334         }
 335         ownerToEntity.put(pickedCandidate, entity);
 336
 337         LOG.debug("Entity {} new owner: {}", entity, pickedCandidate);
 338         currentOwners.put(entity, pickedCandidate);
 339         writeNewOwner(entity, pickedCandidate);
 340     }
 341
 342     private void removeOwner(final DOMEntity entity) {
 343         if (currentOwners.containsKey(entity)) {
 344             // assign empty owner to dd, as we cannot delete data for a key since that would prevent
 345             // writes for the same key
 346             currentOwners.remove(entity);
 347
 348             writeNewOwner(entity, "");
 349         }
 350     }
 351
 352     private void writeNewOwner(final DOMEntity entity, final String candidate) {
 353         ownerReplicator.askUpdate(
 354                 askReplyTo -> new Replicator.Update<>(
 355                         new LWWRegisterKey<>(entity.toString()),
 356                         new LWWRegister<>(node.uniqueAddress(), candidate, 0),
 357                         Replicator.writeLocal(),
 358                         askReplyTo,
 359                         register -> register.withValue(node, candidate, clock)),
 360                 OwnerChanged::new);
 361     }
 362
 363     private Behavior<OwnerSupervisorCommand> onPeerUp(final MemberUpEvent event) {
 364         LOG.debug("Received MemberUp : {}", event);
 365
 366         handleReachableEvent(event.getRoles());
 367         return this;
 368     }
 369
 370     private Behavior<OwnerSupervisorCommand> onPeerReachable(final MemberReachableEvent event) {
 371         LOG.debug("Received MemberReachable : {}", event);
 372
 373         handleReachableEvent(event.getRoles());
 374         return this;
 375     }
 376
 377     private Behavior<OwnerSupervisorCommand> onGetEntities(final GetEntitiesBackendRequest request) {
 378         request.getReplyTo().tell(StatusReply.success(new GetEntitiesBackendReply(currentOwners, currentCandidates)));
 379         return this;
 380     }
 381
 382     private Behavior<OwnerSupervisorCommand> onGetEntity(final GetEntityBackendRequest request) {
 383         final DOMEntity entity = extractEntity(request);
 384         request.getReplyTo().tell(StatusReply.success(
 385                 new GetEntityBackendReply(currentOwners.get(entity), currentCandidates.get(entity))));
 386         return this;
 387     }
 388
 389     private Behavior<OwnerSupervisorCommand> onGetEntityOwner(final GetEntityOwnerBackendRequest request) {
 390         request.getReplyTo().tell(
 391                 StatusReply.success(new GetEntityOwnerBackendReply(currentOwners.get(extractEntity(request)))));
 392         return this;
 393     }
 394
 395     private void handleReachableEvent(final Set<String> roles) {
 396         if (roles.contains(dataCenter)) {
 397             activeMembers.add(extractRole(roles));
 398             assignMissingOwners();
 399         } else {
 400             LOG.debug("Received reachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
 401         }
 402     }
 403
 404     private Behavior<OwnerSupervisorCommand> onPeerDown(final MemberDownEvent event) {
 405         LOG.debug("Received MemberDown : {}", event);
 406
 407         handleUnreachableEvent(event.getRoles());
 408         return this;
 409     }
 410
 411     private Behavior<OwnerSupervisorCommand> onPeerUnreachable(final MemberUnreachableEvent event) {
 412         LOG.debug("Received MemberUnreachable : {}", event);
 413
 414         handleUnreachableEvent(event.getRoles());
 415         return this;
 416     }
 417
 418     private void handleUnreachableEvent(final Set<String> roles) {
 419         if (roles.contains(dataCenter)) {
 420             activeMembers.remove(extractRole(roles));
 421             reassignUnreachableOwners();
 422         } else {
 423             LOG.debug("Received unreachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
 424         }
 425     }
 426
 427     private Set<String> getActiveMembers() {
 428         final CurrentClusterState clusterState = cluster.state();
 429         final Set<String> unreachableRoles = clusterState.getUnreachable().stream()
 430             .map(OwnerSupervisor::extractRole)
 431             .collect(Collectors.toSet());
 432
 433         return StreamSupport.stream(clusterState.getMembers().spliterator(), false)
 434             // We are evaluating the set of roles for each member
 435             .map(Member::getRoles)
 436             // Filter out any members which do not share our dataCenter
 437             .filter(roles -> roles.contains(dataCenter))
 438             // Find first legal role
 439             .map(OwnerSupervisor::extractRole)
 440             // filter out unreachable roles
 441             .filter(role -> !unreachableRoles.contains(role))
 442             .collect(Collectors.toSet());
 443     }
 444
 445     private DOMEntity extractEntity(final AbstractEntityRequest<?> request) {
 446         final var name = request.getName();
 447         final var iid = name.getInstanceIdentifier();
 448         if (iid != null) {
 449             return new DOMEntity(request.getType().getValue(), iidCodec.fromBinding(iid));
 450         }
 451         final var str = verifyNotNull(name.getString(), "Unhandled entity name %s", name);
 452         return new DOMEntity(request.getType().getValue(), str);
 453     }
 454
 455     private static String extractRole(final Member member) {
 456         return extractRole(member.getRoles());
 457     }
 458
 459     private static String extractRole(final Set<String> roles) {
 460         return roles.stream().filter(role -> !role.startsWith(DATACENTER_PREFIX))
 461                 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
 462     }
 463
 464     private static String extractDatacenterRole(final Member member) {
 465         return member.getRoles().stream().filter(role -> role.startsWith(DATACENTER_PREFIX))
 466                 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
 467     }
 468 }