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.function.BiPredicate;
42 import java.util.stream.Collectors;
43 import org.opendaylight.controller.eos.akka.owner.supervisor.command.CandidatesChanged;
44 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DataCenterDeactivated;
45 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DeactivateDataCenter;
46 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberDownEvent;
47 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberReachableEvent;
48 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUnreachableEvent;
49 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUpEvent;
50 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerChanged;
51 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerSupervisorCommand;
52 import org.opendaylight.controller.eos.akka.registry.candidate.CandidateRegistry;
53 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
54 import org.slf4j.Logger;
55 import org.slf4j.LoggerFactory;
56 import scala.collection.JavaConverters;
59 * Responsible for tracking candidates and assigning ownership of entities. This behavior is subscribed to the candidate
60 * registry in distributed-data and picks entity owners based on the current cluster state and registered candidates.
61 * On cluster up/down etc. events the owners are reassigned if possible.
63 public final class OwnerSupervisor extends AbstractBehavior<OwnerSupervisorCommand> {
65 private static final Logger LOG = LoggerFactory.getLogger(OwnerSupervisor.class);
66 private static final String DATACENTER_PREFIX = "dc-";
68 private final ReplicatorMessageAdapter<OwnerSupervisorCommand, LWWRegister<String>> ownerReplicator;
70 // Our own clock implementation so we do not have to rely on synchronized clocks. This basically functions as an
71 // increasing counter which is fine for our needs as we only ever have a single writer since t supervisor is
72 // running in a cluster-singleton
73 private final LWWRegister.Clock<String> clock = (currentTimestamp, value) -> currentTimestamp + 1;
75 private final Cluster cluster;
76 private final SelfUniqueAddress node;
77 private final String dataCenter;
79 private final Set<String> activeMembers;
81 // currently registered candidates
82 private final Map<DOMEntity, Set<String>> currentCandidates;
84 private final Map<DOMEntity, String> currentOwners;
85 // reverse lookup of owner to entity
86 private final Multimap<String, DOMEntity> ownerToEntity = HashMultimap.create();
88 // only reassign owner for those entities that lost this candidate or is not reachable
89 private final BiPredicate<DOMEntity, String> reassignPredicate = (entity, candidate) ->
90 !isActiveCandidate(candidate) || !isCandidateFor(entity, candidate);
92 private OwnerSupervisor(final ActorContext<OwnerSupervisorCommand> context,
93 final Map<DOMEntity, Set<String>> currentCandidates,
94 final Map<DOMEntity, String> currentOwners) {
97 final DistributedData distributedData = DistributedData.get(context.getSystem());
98 final ActorRef<Replicator.Command> replicator = distributedData.replicator();
100 cluster = Cluster.get(context.getSystem());
101 ownerReplicator = new ReplicatorMessageAdapter<>(context, replicator, Duration.ofSeconds(5));
102 dataCenter = extractDatacenterRole(cluster.selfMember());
104 node = distributedData.selfUniqueAddress();
105 activeMembers = getActiveMembers();
107 this.currentCandidates = currentCandidates;
108 this.currentOwners = currentOwners;
110 for (final Map.Entry<DOMEntity, String> entry : currentOwners.entrySet()) {
111 ownerToEntity.put(entry.getValue(), entry.getKey());
114 // check whether we have any unreachable/missing owners
115 reassignUnreachableOwners();
116 assignMissingOwners();
118 final ActorRef<ClusterEvent.MemberEvent> memberEventAdapter =
119 context.messageAdapter(ClusterEvent.MemberEvent.class, event -> {
120 if (event instanceof ClusterEvent.MemberUp) {
121 return new MemberUpEvent(event.member().address(), event.member().getRoles());
123 return new MemberDownEvent(event.member().address(), event.member().getRoles());
126 cluster.subscriptions().tell(Subscribe.create(memberEventAdapter, ClusterEvent.MemberEvent.class));
128 final ActorRef<ClusterEvent.ReachabilityEvent> reachabilityEventAdapter =
129 context.messageAdapter(ClusterEvent.ReachabilityEvent.class, event -> {
130 if (event instanceof ClusterEvent.ReachableMember) {
131 return new MemberReachableEvent(event.member().address(), event.member().getRoles());
133 return new MemberUnreachableEvent(event.member().address(), event.member().getRoles());
136 cluster.subscriptions().tell(Subscribe.create(reachabilityEventAdapter, ClusterEvent.ReachabilityEvent.class));
138 new ReplicatorMessageAdapter<OwnerSupervisorCommand, ORMap<DOMEntity, ORSet<String>>>(context, replicator,
139 Duration.ofSeconds(5)).subscribe(CandidateRegistry.KEY, CandidatesChanged::new);
141 LOG.debug("Owner Supervisor started");
144 public static Behavior<OwnerSupervisorCommand> create(final Map<DOMEntity, Set<String>> currentCandidates,
145 final Map<DOMEntity, String> currentOwners) {
146 return Behaviors.setup(ctx -> new OwnerSupervisor(ctx, currentCandidates, currentOwners));
150 public Receive<OwnerSupervisorCommand> createReceive() {
151 return newReceiveBuilder()
152 .onMessage(CandidatesChanged.class, this::onCandidatesChanged)
153 .onMessage(DeactivateDataCenter.class, this::onDeactivateDatacenter)
154 .onMessage(MemberUpEvent.class, this::onPeerUp)
155 .onMessage(MemberDownEvent.class, this::onPeerDown)
156 .onMessage(MemberReachableEvent.class, this::onPeerReachable)
157 .onMessage(MemberUnreachableEvent.class, this::onPeerUnreachable)
161 private Behavior<OwnerSupervisorCommand> onDeactivateDatacenter(final DeactivateDataCenter command) {
162 LOG.debug("Deactivating Owner Supervisor on {}", cluster.selfMember());
163 command.getReplyTo().tell(DataCenterDeactivated.INSTANCE);
164 return IdleSupervisor.create();
167 private void reassignUnreachableOwners() {
168 final Set<String> ownersToReassign = new HashSet<>();
169 for (final String owner : ownerToEntity.keys()) {
170 if (!activeMembers.contains(owner)) {
171 ownersToReassign.add(owner);
175 for (final String owner : ownersToReassign) {
176 reassignCandidatesFor(owner, ImmutableList.copyOf(ownerToEntity.get(owner)), reassignPredicate);
180 private void assignMissingOwners() {
181 for (final Map.Entry<DOMEntity, Set<String>> entry : currentCandidates.entrySet()) {
182 if (!currentOwners.containsKey(entry.getKey())) {
183 assignOwnerFor(entry.getKey());
188 private Behavior<OwnerSupervisorCommand> onCandidatesChanged(final CandidatesChanged message) {
189 LOG.debug("onCandidatesChanged {}", message.getResponse());
190 if (message.getResponse() instanceof Replicator.Changed) {
191 final Replicator.Changed<ORMap<DOMEntity, ORSet<String>>> changed =
192 (Replicator.Changed<ORMap<DOMEntity, ORSet<String>>>) message.getResponse();
193 processCandidateChanges(changed.get(CandidateRegistry.KEY));
198 private void processCandidateChanges(final ORMap<DOMEntity, ORSet<String>> candidates) {
199 final Map<DOMEntity, ORSet<String>> entries = candidates.getEntries();
200 for (final Map.Entry<DOMEntity, ORSet<String>> entry : entries.entrySet()) {
201 processCandidatesFor(entry.getKey(), entry.getValue());
205 private void processCandidatesFor(final DOMEntity entity, final ORSet<String> receivedCandidates) {
206 LOG.debug("Processing candidates for : {}, new value: {}", entity, receivedCandidates.elements());
208 final Set<String> candidates = JavaConverters.asJava(receivedCandidates.elements());
209 // only insert candidates if there are any to insert, otherwise we would generate unnecessary notification with
211 if (!currentCandidates.containsKey(entity) && !candidates.isEmpty()) {
212 LOG.debug("Candidates missing for entity: {} adding all candidates", entity);
213 currentCandidates.put(entity, new HashSet<>(candidates));
215 LOG.debug("Current state for {} : {}", entity, currentCandidates.get(entity).toString());
216 assignOwnerFor(entity);
221 final Set<String> currentlyPresent = currentCandidates.getOrDefault(entity, Collections.emptySet());
222 final Set<String> difference = ImmutableSet.copyOf(Sets.symmetricDifference(currentlyPresent, candidates));
224 LOG.debug("currently present candidates: {}", currentlyPresent);
225 LOG.debug("difference: {}", difference);
227 final List<String> ownersToReassign = new ArrayList<>();
229 // first add/remove candidates from entities
230 for (final String toCheck : difference) {
231 if (!currentlyPresent.contains(toCheck)) {
233 LOG.debug("Adding new candidate for entity: {} : {}", entity, toCheck);
234 currentCandidates.get(entity).add(toCheck);
236 if (!currentOwners.containsKey(entity)) {
237 // might as well assign right away when we don't have an owner
238 assignOwnerFor(entity);
241 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
245 if (!candidates.contains(toCheck)) {
247 LOG.debug("Removing candidate from entity: {} - {}", entity, toCheck);
248 currentCandidates.get(entity).remove(toCheck);
249 if (ownerToEntity.containsKey(toCheck)) {
250 ownersToReassign.add(toCheck);
255 // then reassign those that need new owners
256 for (final String toReassign : ownersToReassign) {
257 reassignCandidatesFor(toReassign, ImmutableList.copyOf(ownerToEntity.get(toReassign)),
261 if (currentCandidates.get(entity) == null) {
262 LOG.debug("Last candidate removed for {}", entity);
264 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
268 private void reassignCandidatesFor(final String oldOwner, final Collection<DOMEntity> entities,
269 final BiPredicate<DOMEntity, String> predicate) {
270 LOG.debug("Reassigning owners for {}", entities);
271 for (final DOMEntity entity : entities) {
274 if (predicate.test(entity, oldOwner)) {
275 ownerToEntity.remove(oldOwner, entity);
276 assignOwnerFor(entity);
281 private boolean isActiveCandidate(final String candidate) {
282 return activeMembers.contains(candidate);
285 private boolean isCandidateFor(final DOMEntity entity, final String candidate) {
286 return currentCandidates.getOrDefault(entity, Collections.emptySet()).contains(candidate);
289 private void assignOwnerFor(final DOMEntity entity) {
290 final Set<String> candidatesForEntity = currentCandidates.get(entity);
291 if (candidatesForEntity.isEmpty()) {
292 LOG.debug("No candidates present for entity: {}", entity);
297 String pickedCandidate = null;
298 for (final String candidate : candidatesForEntity) {
299 if (activeMembers.contains(candidate)) {
300 pickedCandidate = candidate;
304 if (pickedCandidate == null) {
305 LOG.debug("No candidate is reachable for {}, activeMembers: {}, currentCandidates: {}",
306 entity, activeMembers, currentCandidates.get(entity));
307 // no candidate is reachable so only remove owner if necessary
311 ownerToEntity.put(pickedCandidate, entity);
313 LOG.debug("Entity {} new owner: {}", entity, pickedCandidate);
314 currentOwners.put(entity, pickedCandidate);
315 writeNewOwner(entity, pickedCandidate);
318 private void removeOwner(final DOMEntity entity) {
319 if (currentOwners.containsKey(entity)) {
320 // assign empty owner to dd, as we cannot delete data for a key since that would prevent
321 // writes for the same key
322 currentOwners.remove(entity);
324 writeNewOwner(entity, "");
328 private void writeNewOwner(final DOMEntity entity, final String candidate) {
329 ownerReplicator.askUpdate(
330 askReplyTo -> new Replicator.Update<>(
331 new LWWRegisterKey<>(entity.toString()),
332 new LWWRegister<>(node.uniqueAddress(), candidate, 0),
333 Replicator.writeLocal(),
335 register -> register.withValue(node, candidate, clock)),
339 private Behavior<OwnerSupervisorCommand> onPeerUp(final MemberUpEvent event) {
340 LOG.debug("Received MemberUp : {}", event);
342 handleReachableEvent(event.getRoles());
346 private Behavior<OwnerSupervisorCommand> onPeerReachable(final MemberReachableEvent event) {
347 LOG.debug("Received MemberReachable : {}", event);
349 handleReachableEvent(event.getRoles());
353 private void handleReachableEvent(final Set<String> roles) {
354 if (roles.contains(dataCenter)) {
355 activeMembers.add(extractRole(roles));
356 assignMissingOwners();
358 LOG.debug("Received reachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
362 private Behavior<OwnerSupervisorCommand> onPeerDown(final MemberDownEvent event) {
363 LOG.debug("Received MemberDown : {}", event);
365 handleUnreachableEvent(event.getRoles());
369 private Behavior<OwnerSupervisorCommand> onPeerUnreachable(final MemberUnreachableEvent event) {
370 LOG.debug("Received MemberUnreachable : {}", event);
372 handleUnreachableEvent(event.getRoles());
376 private void handleUnreachableEvent(final Set<String> roles) {
377 if (roles.contains(dataCenter)) {
378 activeMembers.remove(extractRole(roles));
379 reassignUnreachableOwners();
381 LOG.debug("Received unreachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
385 private Set<String> getActiveMembers() {
386 final Set<String> members = new HashSet<>();
387 cluster.state().getMembers().forEach(member -> members.add(extractRole(member)));
388 // filter out unreachable
389 members.removeAll(cluster.state().getUnreachable().stream()
390 .map(OwnerSupervisor::extractRole)
391 .collect(Collectors.toSet()));
393 // filter out members not from our datacenter
394 cluster.state().getMembers().forEach(member -> {
395 if (!member.roles().contains(dataCenter)) {
396 members.remove(extractRole(member));
403 private static String extractRole(final Member member) {
404 return extractRole(member.getRoles());
407 private static String extractRole(final Set<String> roles) {
408 return roles.stream().filter(role -> !role.startsWith(DATACENTER_PREFIX))
409 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
412 private String extractDatacenterRole(final Member member) {
413 return member.getRoles().stream().filter(role -> role.startsWith(DATACENTER_PREFIX))
414 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));