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(OwnerChanged.class, this::onOwnerChanged)
155 .onMessage(MemberUpEvent.class, this::onPeerUp)
156 .onMessage(MemberDownEvent.class, this::onPeerDown)
157 .onMessage(MemberReachableEvent.class, this::onPeerReachable)
158 .onMessage(MemberUnreachableEvent.class, this::onPeerUnreachable)
162 private Behavior<OwnerSupervisorCommand> onDeactivateDatacenter(final DeactivateDataCenter command) {
163 LOG.debug("Deactivating Owner Supervisor on {}", cluster.selfMember());
164 command.getReplyTo().tell(DataCenterDeactivated.INSTANCE);
165 return IdleSupervisor.create();
168 private Behavior<OwnerSupervisorCommand> onOwnerChanged(final OwnerChanged command) {
169 LOG.debug("Owner has changed for {}", command.getResponse().key());
173 private void reassignUnreachableOwners() {
174 final Set<String> ownersToReassign = new HashSet<>();
175 for (final String owner : ownerToEntity.keys()) {
176 if (!activeMembers.contains(owner)) {
177 ownersToReassign.add(owner);
181 for (final String owner : ownersToReassign) {
182 reassignCandidatesFor(owner, ImmutableList.copyOf(ownerToEntity.get(owner)), reassignPredicate);
186 private void assignMissingOwners() {
187 for (final Map.Entry<DOMEntity, Set<String>> entry : currentCandidates.entrySet()) {
188 if (!currentOwners.containsKey(entry.getKey())) {
189 assignOwnerFor(entry.getKey());
194 private Behavior<OwnerSupervisorCommand> onCandidatesChanged(final CandidatesChanged message) {
195 LOG.debug("onCandidatesChanged {}", message.getResponse());
196 if (message.getResponse() instanceof Replicator.Changed) {
197 final Replicator.Changed<ORMap<DOMEntity, ORSet<String>>> changed =
198 (Replicator.Changed<ORMap<DOMEntity, ORSet<String>>>) message.getResponse();
199 processCandidateChanges(changed.get(CandidateRegistry.KEY));
204 private void processCandidateChanges(final ORMap<DOMEntity, ORSet<String>> candidates) {
205 final Map<DOMEntity, ORSet<String>> entries = candidates.getEntries();
206 for (final Map.Entry<DOMEntity, ORSet<String>> entry : entries.entrySet()) {
207 processCandidatesFor(entry.getKey(), entry.getValue());
211 private void processCandidatesFor(final DOMEntity entity, final ORSet<String> receivedCandidates) {
212 LOG.debug("Processing candidates for : {}, new value: {}", entity, receivedCandidates.elements());
214 final Set<String> candidates = JavaConverters.asJava(receivedCandidates.elements());
215 // only insert candidates if there are any to insert, otherwise we would generate unnecessary notification with
217 if (!currentCandidates.containsKey(entity) && !candidates.isEmpty()) {
218 LOG.debug("Candidates missing for entity: {} adding all candidates", entity);
219 currentCandidates.put(entity, new HashSet<>(candidates));
221 LOG.debug("Current state for {} : {}", entity, currentCandidates.get(entity).toString());
222 assignOwnerFor(entity);
227 final Set<String> currentlyPresent = currentCandidates.getOrDefault(entity, Collections.emptySet());
228 final Set<String> difference = ImmutableSet.copyOf(Sets.symmetricDifference(currentlyPresent, candidates));
230 LOG.debug("currently present candidates: {}", currentlyPresent);
231 LOG.debug("difference: {}", difference);
233 final List<String> ownersToReassign = new ArrayList<>();
235 // first add/remove candidates from entities
236 for (final String toCheck : difference) {
237 if (!currentlyPresent.contains(toCheck)) {
239 LOG.debug("Adding new candidate for entity: {} : {}", entity, toCheck);
240 currentCandidates.get(entity).add(toCheck);
242 if (!currentOwners.containsKey(entity)) {
243 // might as well assign right away when we don't have an owner
244 assignOwnerFor(entity);
247 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
251 if (!candidates.contains(toCheck)) {
253 LOG.debug("Removing candidate from entity: {} - {}", entity, toCheck);
254 currentCandidates.get(entity).remove(toCheck);
255 if (ownerToEntity.containsKey(toCheck)) {
256 ownersToReassign.add(toCheck);
261 // then reassign those that need new owners
262 for (final String toReassign : ownersToReassign) {
263 reassignCandidatesFor(toReassign, ImmutableList.copyOf(ownerToEntity.get(toReassign)),
267 if (currentCandidates.get(entity) == null) {
268 LOG.debug("Last candidate removed for {}", entity);
270 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
274 private void reassignCandidatesFor(final String oldOwner, final Collection<DOMEntity> entities,
275 final BiPredicate<DOMEntity, String> predicate) {
276 LOG.debug("Reassigning owners for {}", entities);
277 for (final DOMEntity entity : entities) {
280 if (predicate.test(entity, oldOwner)) {
281 ownerToEntity.remove(oldOwner, entity);
282 assignOwnerFor(entity);
287 private boolean isActiveCandidate(final String candidate) {
288 return activeMembers.contains(candidate);
291 private boolean isCandidateFor(final DOMEntity entity, final String candidate) {
292 return currentCandidates.getOrDefault(entity, Collections.emptySet()).contains(candidate);
295 private void assignOwnerFor(final DOMEntity entity) {
296 final Set<String> candidatesForEntity = currentCandidates.get(entity);
297 if (candidatesForEntity.isEmpty()) {
298 LOG.debug("No candidates present for entity: {}", entity);
303 String pickedCandidate = null;
304 for (final String candidate : candidatesForEntity) {
305 if (activeMembers.contains(candidate)) {
306 pickedCandidate = candidate;
310 if (pickedCandidate == null) {
311 LOG.debug("No candidate is reachable for {}, activeMembers: {}, currentCandidates: {}",
312 entity, activeMembers, currentCandidates.get(entity));
313 // no candidate is reachable so only remove owner if necessary
317 ownerToEntity.put(pickedCandidate, entity);
319 LOG.debug("Entity {} new owner: {}", entity, pickedCandidate);
320 currentOwners.put(entity, pickedCandidate);
321 writeNewOwner(entity, pickedCandidate);
324 private void removeOwner(final DOMEntity entity) {
325 if (currentOwners.containsKey(entity)) {
326 // assign empty owner to dd, as we cannot delete data for a key since that would prevent
327 // writes for the same key
328 currentOwners.remove(entity);
330 writeNewOwner(entity, "");
334 private void writeNewOwner(final DOMEntity entity, final String candidate) {
335 ownerReplicator.askUpdate(
336 askReplyTo -> new Replicator.Update<>(
337 new LWWRegisterKey<>(entity.toString()),
338 new LWWRegister<>(node.uniqueAddress(), candidate, 0),
339 Replicator.writeLocal(),
341 register -> register.withValue(node, candidate, clock)),
345 private Behavior<OwnerSupervisorCommand> onPeerUp(final MemberUpEvent event) {
346 LOG.debug("Received MemberUp : {}", event);
348 handleReachableEvent(event.getRoles());
352 private Behavior<OwnerSupervisorCommand> onPeerReachable(final MemberReachableEvent event) {
353 LOG.debug("Received MemberReachable : {}", event);
355 handleReachableEvent(event.getRoles());
359 private void handleReachableEvent(final Set<String> roles) {
360 if (roles.contains(dataCenter)) {
361 activeMembers.add(extractRole(roles));
362 assignMissingOwners();
364 LOG.debug("Received reachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
368 private Behavior<OwnerSupervisorCommand> onPeerDown(final MemberDownEvent event) {
369 LOG.debug("Received MemberDown : {}", event);
371 handleUnreachableEvent(event.getRoles());
375 private Behavior<OwnerSupervisorCommand> onPeerUnreachable(final MemberUnreachableEvent event) {
376 LOG.debug("Received MemberUnreachable : {}", event);
378 handleUnreachableEvent(event.getRoles());
382 private void handleUnreachableEvent(final Set<String> roles) {
383 if (roles.contains(dataCenter)) {
384 activeMembers.remove(extractRole(roles));
385 reassignUnreachableOwners();
387 LOG.debug("Received unreachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
391 private Set<String> getActiveMembers() {
392 final Set<String> members = new HashSet<>();
393 cluster.state().getMembers().forEach(member -> members.add(extractRole(member)));
394 // filter out unreachable
395 members.removeAll(cluster.state().getUnreachable().stream()
396 .map(OwnerSupervisor::extractRole)
397 .collect(Collectors.toSet()));
399 // filter out members not from our datacenter
400 cluster.state().getMembers().forEach(member -> {
401 if (!member.roles().contains(dataCenter)) {
402 members.remove(extractRole(member));
409 private static String extractRole(final Member member) {
410 return extractRole(member.getRoles());
413 private static String extractRole(final Set<String> roles) {
414 return roles.stream().filter(role -> !role.startsWith(DATACENTER_PREFIX))
415 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
418 private String extractDatacenterRole(final Member member) {
419 return member.getRoles().stream().filter(role -> role.startsWith(DATACENTER_PREFIX))
420 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));