2 * Copyright (c) 2021 PANTHEON.tech, s.r.o. and others. All rights reserved.
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
8 package org.opendaylight.controller.eos.akka.owner.supervisor;
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.ClusterEvent.CurrentClusterState;
18 import akka.cluster.Member;
19 import akka.cluster.ddata.LWWRegister;
20 import akka.cluster.ddata.LWWRegisterKey;
21 import akka.cluster.ddata.ORMap;
22 import akka.cluster.ddata.ORSet;
23 import akka.cluster.ddata.SelfUniqueAddress;
24 import akka.cluster.ddata.typed.javadsl.DistributedData;
25 import akka.cluster.ddata.typed.javadsl.Replicator;
26 import akka.cluster.ddata.typed.javadsl.ReplicatorMessageAdapter;
27 import akka.cluster.typed.Cluster;
28 import akka.cluster.typed.Subscribe;
29 import com.google.common.collect.HashMultimap;
30 import com.google.common.collect.ImmutableList;
31 import com.google.common.collect.ImmutableSet;
32 import com.google.common.collect.Multimap;
33 import com.google.common.collect.Sets;
34 import java.time.Duration;
35 import java.util.ArrayList;
36 import java.util.Collection;
37 import java.util.HashSet;
38 import java.util.List;
41 import java.util.function.BiPredicate;
42 import java.util.stream.Collectors;
43 import java.util.stream.StreamSupport;
44 import org.opendaylight.controller.eos.akka.owner.supervisor.command.AbstractEntityRequest;
45 import org.opendaylight.controller.eos.akka.owner.supervisor.command.CandidatesChanged;
46 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DataCenterDeactivated;
47 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DeactivateDataCenter;
48 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntitiesReply;
49 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntitiesRequest;
50 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityOwnerReply;
51 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityOwnerRequest;
52 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityReply;
53 import org.opendaylight.controller.eos.akka.owner.supervisor.command.GetEntityRequest;
54 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberDownEvent;
55 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberReachableEvent;
56 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUnreachableEvent;
57 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUpEvent;
58 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerChanged;
59 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerSupervisorCommand;
60 import org.opendaylight.controller.eos.akka.registry.candidate.CandidateRegistry;
61 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
62 import org.slf4j.Logger;
63 import org.slf4j.LoggerFactory;
64 import scala.collection.JavaConverters;
67 * Responsible for tracking candidates and assigning ownership of entities. This behavior is subscribed to the candidate
68 * registry in distributed-data and picks entity owners based on the current cluster state and registered candidates.
69 * On cluster up/down etc. events the owners are reassigned if possible.
71 public final class OwnerSupervisor extends AbstractBehavior<OwnerSupervisorCommand> {
73 private static final Logger LOG = LoggerFactory.getLogger(OwnerSupervisor.class);
74 private static final String DATACENTER_PREFIX = "dc-";
76 private final ReplicatorMessageAdapter<OwnerSupervisorCommand, LWWRegister<String>> ownerReplicator;
78 // Our own clock implementation so we do not have to rely on synchronized clocks. This basically functions as an
79 // increasing counter which is fine for our needs as we only ever have a single writer since t supervisor is
80 // running in a cluster-singleton
81 private final LWWRegister.Clock<String> clock = (currentTimestamp, value) -> currentTimestamp + 1;
83 private final Cluster cluster;
84 private final SelfUniqueAddress node;
85 private final String dataCenter;
87 private final Set<String> activeMembers;
89 // currently registered candidates
90 private final Map<DOMEntity, Set<String>> currentCandidates;
92 private final Map<DOMEntity, String> currentOwners;
93 // reverse lookup of owner to entity
94 private final Multimap<String, DOMEntity> ownerToEntity = HashMultimap.create();
96 // only reassign owner for those entities that lost this candidate or is not reachable
97 private final BiPredicate<DOMEntity, String> reassignPredicate = (entity, candidate) ->
98 !isActiveCandidate(candidate) || !isCandidateFor(entity, candidate);
100 private OwnerSupervisor(final ActorContext<OwnerSupervisorCommand> context,
101 final Map<DOMEntity, Set<String>> currentCandidates,
102 final Map<DOMEntity, String> currentOwners) {
105 final DistributedData distributedData = DistributedData.get(context.getSystem());
106 final ActorRef<Replicator.Command> replicator = distributedData.replicator();
108 cluster = Cluster.get(context.getSystem());
109 ownerReplicator = new ReplicatorMessageAdapter<>(context, replicator, Duration.ofSeconds(5));
110 dataCenter = extractDatacenterRole(cluster.selfMember());
112 node = distributedData.selfUniqueAddress();
113 activeMembers = getActiveMembers();
115 this.currentCandidates = currentCandidates;
116 this.currentOwners = currentOwners;
118 for (final Map.Entry<DOMEntity, String> entry : currentOwners.entrySet()) {
119 ownerToEntity.put(entry.getValue(), entry.getKey());
122 // check whether we have any unreachable/missing owners
123 reassignUnreachableOwners();
124 assignMissingOwners();
126 final ActorRef<ClusterEvent.MemberEvent> memberEventAdapter =
127 context.messageAdapter(ClusterEvent.MemberEvent.class, event -> {
128 if (event instanceof ClusterEvent.MemberUp) {
129 return new MemberUpEvent(event.member().address(), event.member().getRoles());
131 return new MemberDownEvent(event.member().address(), event.member().getRoles());
134 cluster.subscriptions().tell(Subscribe.create(memberEventAdapter, ClusterEvent.MemberEvent.class));
136 final ActorRef<ClusterEvent.ReachabilityEvent> reachabilityEventAdapter =
137 context.messageAdapter(ClusterEvent.ReachabilityEvent.class, event -> {
138 if (event instanceof ClusterEvent.ReachableMember) {
139 return new MemberReachableEvent(event.member().address(), event.member().getRoles());
141 return new MemberUnreachableEvent(event.member().address(), event.member().getRoles());
144 cluster.subscriptions().tell(Subscribe.create(reachabilityEventAdapter, ClusterEvent.ReachabilityEvent.class));
146 new ReplicatorMessageAdapter<OwnerSupervisorCommand, ORMap<DOMEntity, ORSet<String>>>(context, replicator,
147 Duration.ofSeconds(5)).subscribe(CandidateRegistry.KEY, CandidatesChanged::new);
149 LOG.debug("Owner Supervisor started");
152 public static Behavior<OwnerSupervisorCommand> create(final Map<DOMEntity, Set<String>> currentCandidates,
153 final Map<DOMEntity, String> currentOwners) {
154 return Behaviors.setup(ctx -> new OwnerSupervisor(ctx, currentCandidates, currentOwners));
158 public Receive<OwnerSupervisorCommand> createReceive() {
159 return newReceiveBuilder()
160 .onMessage(CandidatesChanged.class, this::onCandidatesChanged)
161 .onMessage(DeactivateDataCenter.class, this::onDeactivateDatacenter)
162 .onMessage(OwnerChanged.class, this::onOwnerChanged)
163 .onMessage(MemberUpEvent.class, this::onPeerUp)
164 .onMessage(MemberDownEvent.class, this::onPeerDown)
165 .onMessage(MemberReachableEvent.class, this::onPeerReachable)
166 .onMessage(MemberUnreachableEvent.class, this::onPeerUnreachable)
167 .onMessage(GetEntitiesRequest.class, this::onGetEntities)
168 .onMessage(GetEntityRequest.class, this::onGetEntity)
169 .onMessage(GetEntityOwnerRequest.class, this::onGetEntityOwner)
173 private Behavior<OwnerSupervisorCommand> onDeactivateDatacenter(final DeactivateDataCenter command) {
174 LOG.debug("Deactivating Owner Supervisor on {}", cluster.selfMember());
175 command.getReplyTo().tell(DataCenterDeactivated.INSTANCE);
176 return IdleSupervisor.create();
179 private Behavior<OwnerSupervisorCommand> onOwnerChanged(final OwnerChanged command) {
180 LOG.debug("Owner has changed for {}", command.getResponse().key());
184 private void reassignUnreachableOwners() {
185 final Set<String> ownersToReassign = new HashSet<>();
186 for (final String owner : ownerToEntity.keys()) {
187 if (!activeMembers.contains(owner)) {
188 ownersToReassign.add(owner);
192 for (final String owner : ownersToReassign) {
193 reassignCandidatesFor(owner, ImmutableList.copyOf(ownerToEntity.get(owner)), reassignPredicate);
197 private void assignMissingOwners() {
198 for (final Map.Entry<DOMEntity, Set<String>> entry : currentCandidates.entrySet()) {
199 if (!currentOwners.containsKey(entry.getKey())) {
200 assignOwnerFor(entry.getKey());
205 private Behavior<OwnerSupervisorCommand> onCandidatesChanged(final CandidatesChanged message) {
206 LOG.debug("onCandidatesChanged {}", message.getResponse());
207 if (message.getResponse() instanceof Replicator.Changed) {
208 final Replicator.Changed<ORMap<DOMEntity, ORSet<String>>> changed =
209 (Replicator.Changed<ORMap<DOMEntity, ORSet<String>>>) message.getResponse();
210 processCandidateChanges(changed.get(CandidateRegistry.KEY));
215 private void processCandidateChanges(final ORMap<DOMEntity, ORSet<String>> candidates) {
216 final Map<DOMEntity, ORSet<String>> entries = candidates.getEntries();
217 for (final Map.Entry<DOMEntity, ORSet<String>> entry : entries.entrySet()) {
218 processCandidatesFor(entry.getKey(), entry.getValue());
222 private void processCandidatesFor(final DOMEntity entity, final ORSet<String> receivedCandidates) {
223 LOG.debug("Processing candidates for : {}, new value: {}", entity, receivedCandidates.elements());
225 final Set<String> candidates = JavaConverters.asJava(receivedCandidates.elements());
226 // only insert candidates if there are any to insert, otherwise we would generate unnecessary notification with
228 if (!currentCandidates.containsKey(entity) && !candidates.isEmpty()) {
229 LOG.debug("Candidates missing for entity: {} adding all candidates", entity);
230 currentCandidates.put(entity, new HashSet<>(candidates));
232 LOG.debug("Current state for {} : {}", entity, currentCandidates.get(entity).toString());
233 assignOwnerFor(entity);
238 final Set<String> currentlyPresent = currentCandidates.getOrDefault(entity, Set.of());
239 final Set<String> difference = ImmutableSet.copyOf(Sets.symmetricDifference(currentlyPresent, candidates));
241 LOG.debug("currently present candidates: {}", currentlyPresent);
242 LOG.debug("difference: {}", difference);
244 final List<String> ownersToReassign = new ArrayList<>();
246 // first add/remove candidates from entities
247 for (final String toCheck : difference) {
248 if (!currentlyPresent.contains(toCheck)) {
250 LOG.debug("Adding new candidate for entity: {} : {}", entity, toCheck);
251 currentCandidates.get(entity).add(toCheck);
253 if (!currentOwners.containsKey(entity)) {
254 // might as well assign right away when we don't have an owner
255 assignOwnerFor(entity);
258 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
262 if (!candidates.contains(toCheck)) {
264 LOG.debug("Removing candidate from entity: {} - {}", entity, toCheck);
265 currentCandidates.get(entity).remove(toCheck);
266 if (ownerToEntity.containsKey(toCheck)) {
267 ownersToReassign.add(toCheck);
272 // then reassign those that need new owners
273 for (final String toReassign : ownersToReassign) {
274 reassignCandidatesFor(toReassign, ImmutableList.copyOf(ownerToEntity.get(toReassign)),
278 if (currentCandidates.get(entity) == null) {
279 LOG.debug("Last candidate removed for {}", entity);
281 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
285 private void reassignCandidatesFor(final String oldOwner, final Collection<DOMEntity> entities,
286 final BiPredicate<DOMEntity, String> predicate) {
287 LOG.debug("Reassigning owners for {}", entities);
288 for (final DOMEntity entity : entities) {
289 if (predicate.test(entity, oldOwner)) {
290 ownerToEntity.remove(oldOwner, entity);
291 assignOwnerFor(entity);
296 private boolean isActiveCandidate(final String candidate) {
297 return activeMembers.contains(candidate);
300 private boolean isCandidateFor(final DOMEntity entity, final String candidate) {
301 return currentCandidates.getOrDefault(entity, Set.of()).contains(candidate);
304 private void assignOwnerFor(final DOMEntity entity) {
305 final Set<String> candidatesForEntity = currentCandidates.get(entity);
306 if (candidatesForEntity.isEmpty()) {
307 LOG.debug("No candidates present for entity: {}", entity);
312 String pickedCandidate = null;
313 for (final String candidate : candidatesForEntity) {
314 if (activeMembers.contains(candidate)) {
315 pickedCandidate = candidate;
319 if (pickedCandidate == null) {
320 LOG.debug("No candidate is reachable for {}, activeMembers: {}, currentCandidates: {}",
321 entity, activeMembers, currentCandidates.get(entity));
322 // no candidate is reachable so only remove owner if necessary
326 ownerToEntity.put(pickedCandidate, entity);
328 LOG.debug("Entity {} new owner: {}", entity, pickedCandidate);
329 currentOwners.put(entity, pickedCandidate);
330 writeNewOwner(entity, pickedCandidate);
333 private void removeOwner(final DOMEntity entity) {
334 if (currentOwners.containsKey(entity)) {
335 // assign empty owner to dd, as we cannot delete data for a key since that would prevent
336 // writes for the same key
337 currentOwners.remove(entity);
339 writeNewOwner(entity, "");
343 private void writeNewOwner(final DOMEntity entity, final String candidate) {
344 ownerReplicator.askUpdate(
345 askReplyTo -> new Replicator.Update<>(
346 new LWWRegisterKey<>(entity.toString()),
347 new LWWRegister<>(node.uniqueAddress(), candidate, 0),
348 Replicator.writeLocal(),
350 register -> register.withValue(node, candidate, clock)),
354 private Behavior<OwnerSupervisorCommand> onPeerUp(final MemberUpEvent event) {
355 LOG.debug("Received MemberUp : {}", event);
357 handleReachableEvent(event.getRoles());
361 private Behavior<OwnerSupervisorCommand> onPeerReachable(final MemberReachableEvent event) {
362 LOG.debug("Received MemberReachable : {}", event);
364 handleReachableEvent(event.getRoles());
368 private Behavior<OwnerSupervisorCommand> onGetEntities(final GetEntitiesRequest request) {
369 request.getReplyTo().tell(new GetEntitiesReply(currentOwners, currentCandidates));
373 private Behavior<OwnerSupervisorCommand> onGetEntity(final GetEntityRequest request) {
374 final DOMEntity entity = extractEntity(request);
375 request.getReplyTo().tell(new GetEntityReply(currentOwners.get(entity), currentCandidates.get(entity)));
379 private Behavior<OwnerSupervisorCommand> onGetEntityOwner(final GetEntityOwnerRequest request) {
380 request.getReplyTo().tell(new GetEntityOwnerReply(currentOwners.get(extractEntity(request))));
384 private void handleReachableEvent(final Set<String> roles) {
385 if (roles.contains(dataCenter)) {
386 activeMembers.add(extractRole(roles));
387 assignMissingOwners();
389 LOG.debug("Received reachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
393 private Behavior<OwnerSupervisorCommand> onPeerDown(final MemberDownEvent event) {
394 LOG.debug("Received MemberDown : {}", event);
396 handleUnreachableEvent(event.getRoles());
400 private Behavior<OwnerSupervisorCommand> onPeerUnreachable(final MemberUnreachableEvent event) {
401 LOG.debug("Received MemberUnreachable : {}", event);
403 handleUnreachableEvent(event.getRoles());
407 private void handleUnreachableEvent(final Set<String> roles) {
408 if (roles.contains(dataCenter)) {
409 activeMembers.remove(extractRole(roles));
410 reassignUnreachableOwners();
412 LOG.debug("Received unreachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
416 private Set<String> getActiveMembers() {
417 final CurrentClusterState clusterState = cluster.state();
418 final Set<String> unreachableRoles = clusterState.getUnreachable().stream()
419 .map(OwnerSupervisor::extractRole)
420 .collect(Collectors.toSet());
422 return StreamSupport.stream(clusterState.getMembers().spliterator(), false)
423 // We are evaluating the set of roles for each member
424 .map(Member::getRoles)
425 // Filter out any members which do not share our dataCenter
426 .filter(roles -> roles.contains(dataCenter))
427 // Find first legal role
428 .map(OwnerSupervisor::extractRole)
429 // filter out unreachable roles
430 .filter(role -> !unreachableRoles.contains(role))
431 .collect(Collectors.toSet());
434 private static DOMEntity extractEntity(final AbstractEntityRequest<?> request) {
435 return new DOMEntity(request.getType().getValue(), request.getName().getValue());
438 private static String extractRole(final Member member) {
439 return extractRole(member.getRoles());
442 private static String extractRole(final Set<String> roles) {
443 return roles.stream().filter(role -> !role.startsWith(DATACENTER_PREFIX))
444 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
447 private static String extractDatacenterRole(final Member member) {
448 return member.getRoles().stream().filter(role -> role.startsWith(DATACENTER_PREFIX))
449 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));