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.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;
41 import java.util.stream.Collectors;
42 import org.opendaylight.controller.eos.akka.owner.supervisor.command.CandidatesChanged;
43 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberDownEvent;
44 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberReachableEvent;
45 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUnreachableEvent;
46 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUpEvent;
47 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerChanged;
48 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerSupervisorCommand;
49 import org.opendaylight.controller.eos.akka.registry.candidate.CandidateRegistry;
50 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
51 import org.slf4j.Logger;
52 import org.slf4j.LoggerFactory;
53 import scala.collection.JavaConverters;
56 * Responsible for tracking candidates and assigning ownership of entities. This behavior is subscribed to the candidate
57 * registry in distributed-data and picks entity owners based on the current cluster state and registered candidates.
58 * On cluster up/down etc. events the owners are reassigned if possible.
60 public final class OwnerSupervisor extends AbstractBehavior<OwnerSupervisorCommand> {
62 private static final Logger LOG = LoggerFactory.getLogger(OwnerSupervisor.class);
63 private static final String DATACENTER_PREFIX = "dc";
65 private final ReplicatorMessageAdapter<OwnerSupervisorCommand, LWWRegister<String>> ownerReplicator;
67 // Our own clock implementation so we do not have to rely on synchronized clocks. This basically functions as an
68 // increasing counter which is fine for our needs as we only ever have a single writer since t supervisor is
69 // running in a cluster-singleton
70 private final LWWRegister.Clock<String> clock = (currentTimestamp, value) -> currentTimestamp + 1;
72 private final Cluster cluster;
73 private final SelfUniqueAddress node;
75 private final Set<String> activeMembers;
77 // currently registered candidates
78 private final Map<DOMEntity, Set<String>> currentCandidates;
80 private final Map<DOMEntity, String> currentOwners;
81 // reverse lookup of owner to entity
82 private final Multimap<String, DOMEntity> ownerToEntity = HashMultimap.create();
84 private OwnerSupervisor(final ActorContext<OwnerSupervisorCommand> context,
85 final Map<DOMEntity, Set<String>> currentCandidates,
86 final Map<DOMEntity, String> currentOwners) {
89 final DistributedData distributedData = DistributedData.get(context.getSystem());
90 final ActorRef<Replicator.Command> replicator = distributedData.replicator();
92 this.cluster = Cluster.get(context.getSystem());
93 this.ownerReplicator = new ReplicatorMessageAdapter<>(context, replicator, Duration.ofSeconds(5));
95 this.node = distributedData.selfUniqueAddress();
96 this.activeMembers = getActiveMembers(cluster);
98 this.currentCandidates = currentCandidates;
99 this.currentOwners = currentOwners;
101 for (final Map.Entry<DOMEntity, String> entry : currentOwners.entrySet()) {
102 ownerToEntity.put(entry.getValue(), entry.getKey());
105 // check whether we have any unreachable/missing owners
106 reassignUnreachableOwners();
107 assignMissingOwners();
109 final ActorRef<ClusterEvent.MemberEvent> memberEventAdapter =
110 context.messageAdapter(ClusterEvent.MemberEvent.class, event -> {
111 if (event instanceof ClusterEvent.MemberUp) {
112 return new MemberUpEvent(event.member().address(), event.member().getRoles());
114 return new MemberDownEvent(event.member().address(), event.member().getRoles());
117 cluster.subscriptions().tell(Subscribe.create(memberEventAdapter, ClusterEvent.MemberEvent.class));
119 final ActorRef<ClusterEvent.ReachabilityEvent> reachabilityEventAdapter =
120 context.messageAdapter(ClusterEvent.ReachabilityEvent.class, event -> {
121 if (event instanceof ClusterEvent.ReachableMember) {
122 return new MemberReachableEvent(event.member().address(), event.member().getRoles());
124 return new MemberUnreachableEvent(event.member().address(), event.member().getRoles());
127 cluster.subscriptions().tell(Subscribe.create(reachabilityEventAdapter, ClusterEvent.ReachabilityEvent.class));
129 new ReplicatorMessageAdapter<OwnerSupervisorCommand, ORMap<DOMEntity, ORSet<String>>>(context, replicator,
130 Duration.ofSeconds(5)).subscribe(CandidateRegistry.KEY, CandidatesChanged::new);
132 LOG.debug("Owner Supervisor started");
135 public static Behavior<OwnerSupervisorCommand> create(final Map<DOMEntity, Set<String>> currentCandidates,
136 final Map<DOMEntity, String> currentOwners) {
137 return Behaviors.setup(ctx -> new OwnerSupervisor(ctx, currentCandidates, currentOwners));
141 public Receive<OwnerSupervisorCommand> createReceive() {
142 return newReceiveBuilder()
143 .onMessage(CandidatesChanged.class, this::onCandidatesChanged)
144 .onMessage(MemberUpEvent.class, this::onPeerUp)
145 .onMessage(MemberDownEvent.class, this::onPeerDown)
146 .onMessage(MemberReachableEvent.class, this::onPeerReachable)
147 .onMessage(MemberUnreachableEvent.class, this::onPeerUnreachable)
151 private void reassignUnreachableOwners() {
152 final Set<String> ownersToReassign = new HashSet<>();
153 for (final String owner : ownerToEntity.keys()) {
154 if (!activeMembers.contains(owner)) {
155 ownersToReassign.add(owner);
159 for (final String owner : ownersToReassign) {
160 reassignCandidatesFor(owner, ImmutableList.copyOf(ownerToEntity.get(owner)));
164 private void assignMissingOwners() {
165 for (final Map.Entry<DOMEntity, Set<String>> entry : currentCandidates.entrySet()) {
166 if (!currentOwners.containsKey(entry.getKey())) {
167 assignOwnerFor(entry.getKey());
172 private Behavior<OwnerSupervisorCommand> onCandidatesChanged(final CandidatesChanged message) {
173 LOG.debug("onCandidatesChanged {}", message.getResponse());
174 if (message.getResponse() instanceof Replicator.Changed) {
175 final Replicator.Changed<ORMap<DOMEntity, ORSet<String>>> changed =
176 (Replicator.Changed<ORMap<DOMEntity, ORSet<String>>>) message.getResponse();
177 processCandidateChanges(changed.get(CandidateRegistry.KEY));
182 private void processCandidateChanges(final ORMap<DOMEntity, ORSet<String>> candidates) {
183 final Map<DOMEntity, ORSet<String>> entries = candidates.getEntries();
184 for (final Map.Entry<DOMEntity, ORSet<String>> entry : entries.entrySet()) {
185 processCandidatesFor(entry.getKey(), entry.getValue());
189 private void processCandidatesFor(final DOMEntity entity, final ORSet<String> receivedCandidates) {
190 LOG.debug("Processing candidates for : {}, new value: {}", entity, receivedCandidates.elements());
192 final Set<String> candidates = JavaConverters.asJava(receivedCandidates.elements());
193 // only insert candidates if there are any to insert, otherwise we would generate unnecessary notification with
195 if (!currentCandidates.containsKey(entity) && !candidates.isEmpty()) {
196 LOG.debug("Candidates missing for entity: {} adding all candidates", entity);
197 currentCandidates.put(entity, new HashSet<>(candidates));
199 LOG.debug("Current state for {} : {}", entity, currentCandidates.get(entity).toString());
200 assignOwnerFor(entity);
205 final Set<String> currentlyPresent = currentCandidates.getOrDefault(entity, Collections.emptySet());
206 final Set<String> difference = ImmutableSet.copyOf(Sets.symmetricDifference(currentlyPresent, candidates));
208 LOG.debug("currently present candidates: {}", currentlyPresent);
209 LOG.debug("difference: {}", difference);
211 final List<String> ownersToReassign = new ArrayList<>();
213 // first add/remove candidates from entities
214 for (final String toCheck : difference) {
215 if (!currentlyPresent.contains(toCheck)) {
217 LOG.debug("Adding new candidate for entity: {} : {}", entity, toCheck);
218 currentCandidates.get(entity).add(toCheck);
220 if (!currentOwners.containsKey(entity)) {
221 // might as well assign right away when we don't have an owner
222 assignOwnerFor(entity);
225 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
229 if (!candidates.contains(toCheck)) {
231 LOG.debug("Removing candidate from entity: {} - {}", entity, toCheck);
232 currentCandidates.get(entity).remove(toCheck);
233 if (ownerToEntity.containsKey(toCheck)) {
234 ownersToReassign.add(toCheck);
239 // then reassign those that need new owners
240 for (final String toReassign : ownersToReassign) {
241 reassignCandidatesFor(toReassign, ImmutableList.copyOf(ownerToEntity.get(toReassign)));
244 if (currentCandidates.get(entity) == null) {
245 LOG.debug("Last candidate removed for {}", entity);
247 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
251 private void reassignCandidatesFor(final String oldOwner, final Collection<DOMEntity> entities) {
252 LOG.debug("Reassigning owners for {}", entities);
253 for (final DOMEntity entity : entities) {
255 // only reassign owner for those entities that lost this candidate or is not reachable
256 if (!activeMembers.contains(oldOwner)
257 || !currentCandidates.getOrDefault(entity, Collections.emptySet()).contains(oldOwner)) {
258 ownerToEntity.remove(oldOwner, entity);
259 assignOwnerFor(entity);
264 private void assignOwnerFor(final DOMEntity entity) {
265 final Set<String> candidatesForEntity = currentCandidates.get(entity);
266 if (candidatesForEntity.isEmpty()) {
267 LOG.debug("No candidates present for entity: {}", entity);
272 String pickedCandidate = null;
273 for (final String candidate : candidatesForEntity) {
274 if (activeMembers.contains(candidate)) {
275 pickedCandidate = candidate;
279 if (pickedCandidate == null) {
280 LOG.debug("No candidate is reachable for {}, activeMembers: {}, currentCandidates: {}",
281 entity, activeMembers, currentCandidates.get(entity));
282 // no candidate is reachable so only remove owner if necessary
286 ownerToEntity.put(pickedCandidate, entity);
288 LOG.debug("Entity {} new owner: {}", entity, pickedCandidate);
289 currentOwners.put(entity, pickedCandidate);
290 writeNewOwner(entity, pickedCandidate);
293 private void removeOwner(final DOMEntity entity) {
294 if (currentOwners.containsKey(entity)) {
295 // assign empty owner to dd, as we cannot delete data for a key since that would prevent
296 // writes for the same key
297 currentOwners.remove(entity);
299 writeNewOwner(entity, "");
303 private void writeNewOwner(final DOMEntity entity, final String candidate) {
304 ownerReplicator.askUpdate(
305 askReplyTo -> new Replicator.Update<>(
306 new LWWRegisterKey<>(entity.toString()),
307 new LWWRegister<>(node.uniqueAddress(), candidate, 0),
308 Replicator.writeLocal(),
310 register -> register.withValue(node, candidate, clock)),
314 private Behavior<OwnerSupervisorCommand> onPeerUp(final MemberUpEvent event) {
315 LOG.debug("Received MemberUp : {}", event);
317 handleReachableEvent(event.getRoles());
321 private Behavior<OwnerSupervisorCommand> onPeerReachable(final MemberReachableEvent event) {
322 LOG.debug("Received MemberReachable : {}", event);
324 handleReachableEvent(event.getRoles());
328 private void handleReachableEvent(final Set<String> roles) {
329 activeMembers.add(extractRole(roles));
330 assignMissingOwners();
333 private Behavior<OwnerSupervisorCommand> onPeerDown(final MemberDownEvent event) {
334 LOG.debug("Received MemberDown : {}", event);
336 handleUnreachableEvent(event.getRoles());
340 private Behavior<OwnerSupervisorCommand> onPeerUnreachable(final MemberUnreachableEvent event) {
341 LOG.debug("Received MemberUnreachable : {}", event);
343 handleUnreachableEvent(event.getRoles());
347 private void handleUnreachableEvent(final Set<String> roles) {
348 activeMembers.remove(extractRole(roles));
349 reassignUnreachableOwners();
352 private static Set<String> getActiveMembers(final Cluster cluster) {
353 final Set<String> activeMembers = new HashSet<>();
354 cluster.state().getMembers().forEach(member -> activeMembers.add(extractRole(member)));
355 activeMembers.removeAll(cluster.state().getUnreachable().stream()
356 .map(OwnerSupervisor::extractRole).collect(Collectors.toSet()));
358 return activeMembers;
361 private static String extractRole(final Member member) {
362 return extractRole(member.getRoles());
365 private static String extractRole(final Set<String> roles) {
366 return roles.stream().filter(role -> !role.contains(DATACENTER_PREFIX))
367 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));