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.DataCenterDeactivated;
44 import org.opendaylight.controller.eos.akka.owner.supervisor.command.DeactivateDataCenter;
45 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberDownEvent;
46 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberReachableEvent;
47 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUnreachableEvent;
48 import org.opendaylight.controller.eos.akka.owner.supervisor.command.MemberUpEvent;
49 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerChanged;
50 import org.opendaylight.controller.eos.akka.owner.supervisor.command.OwnerSupervisorCommand;
51 import org.opendaylight.controller.eos.akka.registry.candidate.CandidateRegistry;
52 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
53 import org.slf4j.Logger;
54 import org.slf4j.LoggerFactory;
55 import scala.collection.JavaConverters;
58 * Responsible for tracking candidates and assigning ownership of entities. This behavior is subscribed to the candidate
59 * registry in distributed-data and picks entity owners based on the current cluster state and registered candidates.
60 * On cluster up/down etc. events the owners are reassigned if possible.
62 public final class OwnerSupervisor extends AbstractBehavior<OwnerSupervisorCommand> {
64 private static final Logger LOG = LoggerFactory.getLogger(OwnerSupervisor.class);
65 private static final String DATACENTER_PREFIX = "dc-";
67 private final ReplicatorMessageAdapter<OwnerSupervisorCommand, LWWRegister<String>> ownerReplicator;
69 // Our own clock implementation so we do not have to rely on synchronized clocks. This basically functions as an
70 // increasing counter which is fine for our needs as we only ever have a single writer since t supervisor is
71 // running in a cluster-singleton
72 private final LWWRegister.Clock<String> clock = (currentTimestamp, value) -> currentTimestamp + 1;
74 private final Cluster cluster;
75 private final SelfUniqueAddress node;
76 private final String dataCenter;
78 private final Set<String> activeMembers;
80 // currently registered candidates
81 private final Map<DOMEntity, Set<String>> currentCandidates;
83 private final Map<DOMEntity, String> currentOwners;
84 // reverse lookup of owner to entity
85 private final Multimap<String, DOMEntity> ownerToEntity = HashMultimap.create();
87 private OwnerSupervisor(final ActorContext<OwnerSupervisorCommand> context,
88 final Map<DOMEntity, Set<String>> currentCandidates,
89 final Map<DOMEntity, String> currentOwners) {
92 final DistributedData distributedData = DistributedData.get(context.getSystem());
93 final ActorRef<Replicator.Command> replicator = distributedData.replicator();
95 cluster = Cluster.get(context.getSystem());
96 ownerReplicator = new ReplicatorMessageAdapter<>(context, replicator, Duration.ofSeconds(5));
97 dataCenter = extractDatacenterRole(cluster.selfMember());
99 node = distributedData.selfUniqueAddress();
100 activeMembers = getActiveMembers();
102 this.currentCandidates = currentCandidates;
103 this.currentOwners = currentOwners;
105 for (final Map.Entry<DOMEntity, String> entry : currentOwners.entrySet()) {
106 ownerToEntity.put(entry.getValue(), entry.getKey());
109 // check whether we have any unreachable/missing owners
110 reassignUnreachableOwners();
111 assignMissingOwners();
113 final ActorRef<ClusterEvent.MemberEvent> memberEventAdapter =
114 context.messageAdapter(ClusterEvent.MemberEvent.class, event -> {
115 if (event instanceof ClusterEvent.MemberUp) {
116 return new MemberUpEvent(event.member().address(), event.member().getRoles());
118 return new MemberDownEvent(event.member().address(), event.member().getRoles());
121 cluster.subscriptions().tell(Subscribe.create(memberEventAdapter, ClusterEvent.MemberEvent.class));
123 final ActorRef<ClusterEvent.ReachabilityEvent> reachabilityEventAdapter =
124 context.messageAdapter(ClusterEvent.ReachabilityEvent.class, event -> {
125 if (event instanceof ClusterEvent.ReachableMember) {
126 return new MemberReachableEvent(event.member().address(), event.member().getRoles());
128 return new MemberUnreachableEvent(event.member().address(), event.member().getRoles());
131 cluster.subscriptions().tell(Subscribe.create(reachabilityEventAdapter, ClusterEvent.ReachabilityEvent.class));
133 new ReplicatorMessageAdapter<OwnerSupervisorCommand, ORMap<DOMEntity, ORSet<String>>>(context, replicator,
134 Duration.ofSeconds(5)).subscribe(CandidateRegistry.KEY, CandidatesChanged::new);
136 LOG.debug("Owner Supervisor started");
139 public static Behavior<OwnerSupervisorCommand> create(final Map<DOMEntity, Set<String>> currentCandidates,
140 final Map<DOMEntity, String> currentOwners) {
141 return Behaviors.setup(ctx -> new OwnerSupervisor(ctx, currentCandidates, currentOwners));
145 public Receive<OwnerSupervisorCommand> createReceive() {
146 return newReceiveBuilder()
147 .onMessage(CandidatesChanged.class, this::onCandidatesChanged)
148 .onMessage(DeactivateDataCenter.class, this::onDeactivateDatacenter)
149 .onMessage(MemberUpEvent.class, this::onPeerUp)
150 .onMessage(MemberDownEvent.class, this::onPeerDown)
151 .onMessage(MemberReachableEvent.class, this::onPeerReachable)
152 .onMessage(MemberUnreachableEvent.class, this::onPeerUnreachable)
156 private Behavior<OwnerSupervisorCommand> onDeactivateDatacenter(final DeactivateDataCenter command) {
157 LOG.debug("Deactivating Owner Supervisor on {}", cluster.selfMember());
158 command.getReplyTo().tell(DataCenterDeactivated.INSTANCE);
159 return IdleSupervisor.create();
162 private void reassignUnreachableOwners() {
163 final Set<String> ownersToReassign = new HashSet<>();
164 for (final String owner : ownerToEntity.keys()) {
165 if (!activeMembers.contains(owner)) {
166 ownersToReassign.add(owner);
170 for (final String owner : ownersToReassign) {
171 reassignCandidatesFor(owner, ImmutableList.copyOf(ownerToEntity.get(owner)));
175 private void assignMissingOwners() {
176 for (final Map.Entry<DOMEntity, Set<String>> entry : currentCandidates.entrySet()) {
177 if (!currentOwners.containsKey(entry.getKey())) {
178 assignOwnerFor(entry.getKey());
183 private Behavior<OwnerSupervisorCommand> onCandidatesChanged(final CandidatesChanged message) {
184 LOG.debug("onCandidatesChanged {}", message.getResponse());
185 if (message.getResponse() instanceof Replicator.Changed) {
186 final Replicator.Changed<ORMap<DOMEntity, ORSet<String>>> changed =
187 (Replicator.Changed<ORMap<DOMEntity, ORSet<String>>>) message.getResponse();
188 processCandidateChanges(changed.get(CandidateRegistry.KEY));
193 private void processCandidateChanges(final ORMap<DOMEntity, ORSet<String>> candidates) {
194 final Map<DOMEntity, ORSet<String>> entries = candidates.getEntries();
195 for (final Map.Entry<DOMEntity, ORSet<String>> entry : entries.entrySet()) {
196 processCandidatesFor(entry.getKey(), entry.getValue());
200 private void processCandidatesFor(final DOMEntity entity, final ORSet<String> receivedCandidates) {
201 LOG.debug("Processing candidates for : {}, new value: {}", entity, receivedCandidates.elements());
203 final Set<String> candidates = JavaConverters.asJava(receivedCandidates.elements());
204 // only insert candidates if there are any to insert, otherwise we would generate unnecessary notification with
206 if (!currentCandidates.containsKey(entity) && !candidates.isEmpty()) {
207 LOG.debug("Candidates missing for entity: {} adding all candidates", entity);
208 currentCandidates.put(entity, new HashSet<>(candidates));
210 LOG.debug("Current state for {} : {}", entity, currentCandidates.get(entity).toString());
211 assignOwnerFor(entity);
216 final Set<String> currentlyPresent = currentCandidates.getOrDefault(entity, Collections.emptySet());
217 final Set<String> difference = ImmutableSet.copyOf(Sets.symmetricDifference(currentlyPresent, candidates));
219 LOG.debug("currently present candidates: {}", currentlyPresent);
220 LOG.debug("difference: {}", difference);
222 final List<String> ownersToReassign = new ArrayList<>();
224 // first add/remove candidates from entities
225 for (final String toCheck : difference) {
226 if (!currentlyPresent.contains(toCheck)) {
228 LOG.debug("Adding new candidate for entity: {} : {}", entity, toCheck);
229 currentCandidates.get(entity).add(toCheck);
231 if (!currentOwners.containsKey(entity)) {
232 // might as well assign right away when we don't have an owner
233 assignOwnerFor(entity);
236 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
240 if (!candidates.contains(toCheck)) {
242 LOG.debug("Removing candidate from entity: {} - {}", entity, toCheck);
243 currentCandidates.get(entity).remove(toCheck);
244 if (ownerToEntity.containsKey(toCheck)) {
245 ownersToReassign.add(toCheck);
250 // then reassign those that need new owners
251 for (final String toReassign : ownersToReassign) {
252 reassignCandidatesFor(toReassign, ImmutableList.copyOf(ownerToEntity.get(toReassign)));
255 if (currentCandidates.get(entity) == null) {
256 LOG.debug("Last candidate removed for {}", entity);
258 LOG.debug("Current state for entity: {} : {}", entity, currentCandidates.get(entity).toString());
262 private void reassignCandidatesFor(final String oldOwner, final Collection<DOMEntity> entities) {
263 LOG.debug("Reassigning owners for {}", entities);
264 for (final DOMEntity entity : entities) {
266 // only reassign owner for those entities that lost this candidate or is not reachable
267 if (!activeMembers.contains(oldOwner)
268 || !currentCandidates.getOrDefault(entity, Collections.emptySet()).contains(oldOwner)) {
269 ownerToEntity.remove(oldOwner, entity);
270 assignOwnerFor(entity);
275 private void assignOwnerFor(final DOMEntity entity) {
276 final Set<String> candidatesForEntity = currentCandidates.get(entity);
277 if (candidatesForEntity.isEmpty()) {
278 LOG.debug("No candidates present for entity: {}", entity);
283 String pickedCandidate = null;
284 for (final String candidate : candidatesForEntity) {
285 if (activeMembers.contains(candidate)) {
286 pickedCandidate = candidate;
290 if (pickedCandidate == null) {
291 LOG.debug("No candidate is reachable for {}, activeMembers: {}, currentCandidates: {}",
292 entity, activeMembers, currentCandidates.get(entity));
293 // no candidate is reachable so only remove owner if necessary
297 ownerToEntity.put(pickedCandidate, entity);
299 LOG.debug("Entity {} new owner: {}", entity, pickedCandidate);
300 currentOwners.put(entity, pickedCandidate);
301 writeNewOwner(entity, pickedCandidate);
304 private void removeOwner(final DOMEntity entity) {
305 if (currentOwners.containsKey(entity)) {
306 // assign empty owner to dd, as we cannot delete data for a key since that would prevent
307 // writes for the same key
308 currentOwners.remove(entity);
310 writeNewOwner(entity, "");
314 private void writeNewOwner(final DOMEntity entity, final String candidate) {
315 ownerReplicator.askUpdate(
316 askReplyTo -> new Replicator.Update<>(
317 new LWWRegisterKey<>(entity.toString()),
318 new LWWRegister<>(node.uniqueAddress(), candidate, 0),
319 Replicator.writeLocal(),
321 register -> register.withValue(node, candidate, clock)),
325 private Behavior<OwnerSupervisorCommand> onPeerUp(final MemberUpEvent event) {
326 LOG.debug("Received MemberUp : {}", event);
328 handleReachableEvent(event.getRoles());
332 private Behavior<OwnerSupervisorCommand> onPeerReachable(final MemberReachableEvent event) {
333 LOG.debug("Received MemberReachable : {}", event);
335 handleReachableEvent(event.getRoles());
339 private void handleReachableEvent(final Set<String> roles) {
340 if (roles.contains(dataCenter)) {
341 activeMembers.add(extractRole(roles));
342 assignMissingOwners();
344 LOG.debug("Received reachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
348 private Behavior<OwnerSupervisorCommand> onPeerDown(final MemberDownEvent event) {
349 LOG.debug("Received MemberDown : {}", event);
351 handleUnreachableEvent(event.getRoles());
355 private Behavior<OwnerSupervisorCommand> onPeerUnreachable(final MemberUnreachableEvent event) {
356 LOG.debug("Received MemberUnreachable : {}", event);
358 handleUnreachableEvent(event.getRoles());
362 private void handleUnreachableEvent(final Set<String> roles) {
363 if (roles.contains(dataCenter)) {
364 activeMembers.remove(extractRole(roles));
365 reassignUnreachableOwners();
367 LOG.debug("Received unreachable event from a foreign datacenter, Ignoring... Roles: {}", roles);
371 private Set<String> getActiveMembers() {
372 final Set<String> members = new HashSet<>();
373 cluster.state().getMembers().forEach(member -> members.add(extractRole(member)));
374 // filter out unreachable
375 members.removeAll(cluster.state().getUnreachable().stream()
376 .map(OwnerSupervisor::extractRole)
377 .collect(Collectors.toSet()));
379 // filter out members not from our datacenter
380 cluster.state().getMembers().forEach(member -> {
381 if (!member.roles().contains(dataCenter)) {
382 members.remove(extractRole(member));
389 private static String extractRole(final Member member) {
390 return extractRole(member.getRoles());
393 private static String extractRole(final Set<String> roles) {
394 return roles.stream().filter(role -> !role.startsWith(DATACENTER_PREFIX))
395 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));
398 private String extractDatacenterRole(final Member member) {
399 return member.getRoles().stream().filter(role -> role.startsWith(DATACENTER_PREFIX))
400 .findFirst().orElseThrow(() -> new IllegalArgumentException("No valid role found."));