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 static com.google.common.base.Verify.verifyNotNull;
11 import static java.util.Objects.requireNonNull;
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;
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;
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.
75 public final class OwnerSupervisor extends AbstractBehavior<OwnerSupervisorCommand> {
77 private static final Logger LOG = LoggerFactory.getLogger(OwnerSupervisor.class);
78 private static final String DATACENTER_PREFIX = "dc-";
80 private final ReplicatorMessageAdapter<OwnerSupervisorCommand, LWWRegister<String>> ownerReplicator;
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;
87 private final Cluster cluster;
88 private final SelfUniqueAddress node;
89 private final String dataCenter;
91 private final Set<String> activeMembers;
93 // currently registered candidates
94 private final Map<DOMEntity, Set<String>> currentCandidates;
96 private final Map<DOMEntity, String> currentOwners;
97 // reverse lookup of owner to entity
98 private final Multimap<String, DOMEntity> ownerToEntity = HashMultimap.create();
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);
104 private final BindingInstanceIdentifierCodec iidCodec;
106 private OwnerSupervisor(final ActorContext<OwnerSupervisorCommand> context,
107 final Map<DOMEntity, Set<String>> currentCandidates,
108 final Map<DOMEntity, String> currentOwners,
109 final BindingInstanceIdentifierCodec iidCodec) {
111 this.iidCodec = requireNonNull(iidCodec);
113 final DistributedData distributedData = DistributedData.get(context.getSystem());
114 final ActorRef<Replicator.Command> replicator = distributedData.replicator();
116 cluster = Cluster.get(context.getSystem());
117 ownerReplicator = new ReplicatorMessageAdapter<>(context, replicator, Duration.ofSeconds(5));
118 dataCenter = extractDatacenterRole(cluster.selfMember());
120 node = distributedData.selfUniqueAddress();
121 activeMembers = getActiveMembers();
123 this.currentCandidates = currentCandidates;
124 this.currentOwners = currentOwners;
126 for (final Map.Entry<DOMEntity, String> entry : currentOwners.entrySet()) {
127 ownerToEntity.put(entry.getValue(), entry.getKey());
130 // check whether we have any unreachable/missing owners
131 reassignUnreachableOwners();
132 assignMissingOwners();
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());
139 return new MemberDownEvent(event.member().address(), event.member().getRoles());
142 cluster.subscriptions().tell(Subscribe.create(memberEventAdapter, ClusterEvent.MemberEvent.class));
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());
149 return new MemberUnreachableEvent(event.member().address(), event.member().getRoles());
152 cluster.subscriptions().tell(Subscribe.create(reachabilityEventAdapter, ClusterEvent.ReachabilityEvent.class));
154 new ReplicatorMessageAdapter<OwnerSupervisorCommand, ORMap<DOMEntity, ORSet<String>>>(context, replicator,
155 Duration.ofSeconds(5)).subscribe(CandidateRegistry.KEY, CandidatesChanged::new);
157 LOG.debug("Owner Supervisor started");
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));
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)
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);
187 private Behavior<OwnerSupervisorCommand> onOwnerChanged(final OwnerChanged command) {
188 LOG.debug("Owner has changed for {}", command.getResponse().key());
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);
200 for (final String owner : ownersToReassign) {
201 reassignCandidatesFor(owner, ImmutableList.copyOf(ownerToEntity.get(owner)), reassignPredicate);
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());
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));
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());
230 private void processCandidatesFor(final DOMEntity entity, final ORSet<String> receivedCandidates) {
231 LOG.debug("Processing candidates for : {}, new value: {}", entity, receivedCandidates.elements());
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
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));
240 LOG.debug("Current state for {} : {}", entity, currentCandidates.get(entity).toString());
241 assignOwnerFor(entity);
246 final Set<String> currentlyPresent = currentCandidates.getOrDefault(entity, Set.of());
247 final Set<String> difference = ImmutableSet.copyOf(Sets.symmetricDifference(currentlyPresent, candidates));
249 LOG.debug("currently present candidates: {}", currentlyPresent);
250 LOG.debug("difference: {}", difference);
252 final List<String> ownersToReassign = new ArrayList<>();
254 // first add/remove candidates from entities
255 for (final String toCheck : difference) {
256 if (!currentlyPresent.contains(toCheck)) {
258 LOG.debug("Adding new candidate for entity: {} : {}", entity, toCheck);
259 currentCandidates.get(entity).add(toCheck);
261 if (!currentOwners.containsKey(entity)) {
262 // might as well assign right away when we don't have an owner
263 assignOwnerFor(entity);
266 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
270 if (!candidates.contains(toCheck)) {
272 LOG.debug("Removing candidate from entity: {} - {}", entity, toCheck);
273 currentCandidates.get(entity).remove(toCheck);
274 if (ownerToEntity.containsKey(toCheck)) {
275 ownersToReassign.add(toCheck);
280 // then reassign those that need new owners
281 for (final String toReassign : ownersToReassign) {
282 reassignCandidatesFor(toReassign, ImmutableList.copyOf(ownerToEntity.get(toReassign)),
286 if (currentCandidates.get(entity) == null) {
287 LOG.debug("Last candidate removed for {}", entity);
289 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
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);
304 private boolean isActiveCandidate(final String candidate) {
305 return activeMembers.contains(candidate);
308 private boolean isCandidateFor(final DOMEntity entity, final String candidate) {
309 return currentCandidates.getOrDefault(entity, Set.of()).contains(candidate);
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);
320 String pickedCandidate = null;
321 for (final String candidate : candidatesForEntity) {
322 if (activeMembers.contains(candidate)) {
323 pickedCandidate = candidate;
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
334 ownerToEntity.put(pickedCandidate, entity);
336 LOG.debug("Entity {} new owner: {}", entity, pickedCandidate);
337 currentOwners.put(entity, pickedCandidate);
338 writeNewOwner(entity, pickedCandidate);
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);
347 writeNewOwner(entity, "");
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(),
358 register -> register.withValue(node, candidate, clock)),
362 private Behavior<OwnerSupervisorCommand> onPeerUp(final MemberUpEvent event) {
363 LOG.debug("Received MemberUp : {}", event);
365 handleReachableEvent(event.getRoles());
369 private Behavior<OwnerSupervisorCommand> onPeerReachable(final MemberReachableEvent event) {
370 LOG.debug("Received MemberReachable : {}", event);
372 handleReachableEvent(event.getRoles());
376 private Behavior<OwnerSupervisorCommand> onGetEntities(final GetEntitiesRequest request) {
377 request.getReplyTo().tell(new GetEntitiesReply(currentOwners, currentCandidates));
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)));
387 private Behavior<OwnerSupervisorCommand> onGetEntityOwner(final GetEntityOwnerRequest request) {
388 request.getReplyTo().tell(new GetEntityOwnerReply(currentOwners.get(extractEntity(request))));
392 private void handleReachableEvent(final Set<String> roles) {
393 if (roles.contains(dataCenter)) {
394 activeMembers.add(extractRole(roles));
395 assignMissingOwners();
397 LOG.debug("Received reachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
401 private Behavior<OwnerSupervisorCommand> onPeerDown(final MemberDownEvent event) {
402 LOG.debug("Received MemberDown : {}", event);
404 handleUnreachableEvent(event.getRoles());
408 private Behavior<OwnerSupervisorCommand> onPeerUnreachable(final MemberUnreachableEvent event) {
409 LOG.debug("Received MemberUnreachable : {}", event);
411 handleUnreachableEvent(event.getRoles());
415 private void handleUnreachableEvent(final Set<String> roles) {
416 if (roles.contains(dataCenter)) {
417 activeMembers.remove(extractRole(roles));
418 reassignUnreachableOwners();
420 LOG.debug("Received unreachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
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());
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());
442 private DOMEntity extractEntity(final AbstractEntityRequest<?> request) {
443 final var name = request.getName();
444 final var iid = name.getInstanceIdentifier();
446 return new DOMEntity(request.getType().getValue(), iidCodec.fromBinding(iid));
448 final var str = verifyNotNull(name.getString(), "Unhandled entity name %s", name);
449 return new DOMEntity(request.getType().getValue(), str);
452 private static String extractRole(final Member member) {
453 return extractRole(member.getRoles());
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."));
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."));