/*
* Copyright (c) 2015 Brocade Communications Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.controller.cluster.datastore.entityownership;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.CANDIDATE_NAME_NODE_ID;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.CANDIDATE_NODE_ID;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_ID_NODE_ID;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_ID_QNAME;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_NODE_ID;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_OWNERS_PATH;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_OWNER_NODE_ID;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_OWNER_QNAME;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_TYPES_PATH;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_TYPE_NODE_ID;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_TYPE_QNAME;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.candidateNodeKey;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.candidatePath;
import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.entityOwnersWithCandidate;
import akka.actor.ActorRef;
import akka.actor.ActorSelection;
import akka.actor.Cancellable;
import akka.cluster.Cluster;
import akka.cluster.ClusterEvent.CurrentClusterState;
import akka.cluster.Member;
import akka.cluster.MemberStatus;
import akka.pattern.Patterns;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.base.Strings;
import com.google.common.collect.ImmutableSet;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.TimeUnit;
import org.opendaylight.controller.cluster.access.concepts.MemberName;
import org.opendaylight.controller.cluster.datastore.DatastoreContext;
import org.opendaylight.controller.cluster.datastore.Shard;
import org.opendaylight.controller.cluster.datastore.entityownership.messages.CandidateAdded;
import org.opendaylight.controller.cluster.datastore.entityownership.messages.CandidateRemoved;
import org.opendaylight.controller.cluster.datastore.entityownership.messages.RegisterCandidateLocal;
import org.opendaylight.controller.cluster.datastore.entityownership.messages.RegisterListenerLocal;
import org.opendaylight.controller.cluster.datastore.entityownership.messages.RemoveAllCandidates;
import org.opendaylight.controller.cluster.datastore.entityownership.messages.SelectOwner;
import org.opendaylight.controller.cluster.datastore.entityownership.messages.UnregisterCandidateLocal;
import org.opendaylight.controller.cluster.datastore.entityownership.messages.UnregisterListenerLocal;
import org.opendaylight.controller.cluster.datastore.entityownership.selectionstrategy.EntityOwnerSelectionStrategy;
import org.opendaylight.controller.cluster.datastore.entityownership.selectionstrategy.EntityOwnerSelectionStrategyConfig;
import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
import org.opendaylight.controller.cluster.datastore.messages.PeerDown;
import org.opendaylight.controller.cluster.datastore.messages.PeerUp;
import org.opendaylight.controller.cluster.datastore.messages.SuccessReply;
import org.opendaylight.controller.cluster.datastore.modification.DeleteModification;
import org.opendaylight.controller.cluster.datastore.modification.MergeModification;
import org.opendaylight.controller.cluster.datastore.modification.WriteModification;
import org.opendaylight.controller.cluster.raft.RaftState;
import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
import org.opendaylight.yangtools.yang.data.api.schema.MapNode;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
import scala.concurrent.Future;
import scala.concurrent.duration.FiniteDuration;
/**
* Special Shard for EntityOwnership.
*
* @author Thomas Pantelis
*/
class EntityOwnershipShard extends Shard {
private final MemberName localMemberName;
private final EntityOwnershipShardCommitCoordinator commitCoordinator;
private final EntityOwnershipListenerSupport listenerSupport;
private final Set<MemberName> downPeerMemberNames = new HashSet<>();
private final EntityOwnerSelectionStrategyConfig strategyConfig;
private final Map<YangInstanceIdentifier, Cancellable> entityToScheduledOwnershipTask = new HashMap<>();
private final EntityOwnershipStatistics entityOwnershipStatistics;
private boolean removeAllInitialCandidates = true;
protected EntityOwnershipShard(final Builder builder) {
super(builder);
this.localMemberName = builder.localMemberName;
this.commitCoordinator = new EntityOwnershipShardCommitCoordinator(builder.localMemberName, LOG);
this.listenerSupport = new EntityOwnershipListenerSupport(getContext(), persistenceId());
this.strategyConfig = builder.ownerSelectionStrategyConfig;
this.entityOwnershipStatistics = new EntityOwnershipStatistics();
this.entityOwnershipStatistics.init(getDataStore());
}
private static DatastoreContext noPersistenceDatastoreContext(final DatastoreContext datastoreContext) {
return DatastoreContext.newBuilderFrom(datastoreContext).persistent(false).build();
}
@Override
protected void onDatastoreContext(final DatastoreContext context) {
super.onDatastoreContext(noPersistenceDatastoreContext(context));
}
@Override
protected void onRecoveryComplete() {
super.onRecoveryComplete();
new CandidateListChangeListener(getSelf(), persistenceId()).init(getDataStore());
new EntityOwnerChangeListener(localMemberName, listenerSupport).init(getDataStore());
}
@Override
public void handleNonRaftCommand(final Object message) {
if (message instanceof RegisterCandidateLocal) {
onRegisterCandidateLocal((RegisterCandidateLocal) message);
} else if (message instanceof UnregisterCandidateLocal) {
onUnregisterCandidateLocal((UnregisterCandidateLocal) message);
} else if (message instanceof CandidateAdded) {
onCandidateAdded((CandidateAdded) message);
} else if (message instanceof CandidateRemoved) {
onCandidateRemoved((CandidateRemoved) message);
} else if (message instanceof PeerDown) {
onPeerDown((PeerDown) message);
} else if (message instanceof PeerUp) {
onPeerUp((PeerUp) message);
} else if (message instanceof RegisterListenerLocal) {
onRegisterListenerLocal((RegisterListenerLocal) message);
} else if (message instanceof UnregisterListenerLocal) {
onUnregisterListenerLocal((UnregisterListenerLocal) message);
} else if (message instanceof SelectOwner) {
onSelectOwner((SelectOwner) message);
} else if (message instanceof RemoveAllCandidates) {
onRemoveAllCandidates((RemoveAllCandidates) message);
} else if (!commitCoordinator.handleMessage(message, this)) {
super.handleNonRaftCommand(message);
}
}
private void onRemoveAllCandidates(final RemoveAllCandidates message) {
LOG.debug("{}: onRemoveAllCandidates: {}", persistenceId(), message);
removeCandidateFromEntities(message.getMemberName());
}
private void onSelectOwner(final SelectOwner selectOwner) {
LOG.debug("{}: onSelectOwner: {}", persistenceId(), selectOwner);
String currentOwner = getCurrentOwner(selectOwner.getEntityPath());
if (Strings.isNullOrEmpty(currentOwner)) {
writeNewOwner(selectOwner.getEntityPath(), newOwner(currentOwner, selectOwner.getAllCandidates(),
selectOwner.getOwnerSelectionStrategy()));
Cancellable cancellable = entityToScheduledOwnershipTask.get(selectOwner.getEntityPath());
if (cancellable != null) {
if (!cancellable.isCancelled()) {
cancellable.cancel();
}
entityToScheduledOwnershipTask.remove(selectOwner.getEntityPath());
}
}
}
private void onRegisterCandidateLocal(final RegisterCandidateLocal registerCandidate) {
LOG.debug("{}: onRegisterCandidateLocal: {}", persistenceId(), registerCandidate);
NormalizedNode<?, ?> entityOwners = entityOwnersWithCandidate(registerCandidate.getEntity().getType(),
registerCandidate.getEntity().getIdentifier(), localMemberName.getName());
commitCoordinator.commitModification(new MergeModification(ENTITY_OWNERS_PATH, entityOwners), this);
getSender().tell(SuccessReply.INSTANCE, getSelf());
}
private void onUnregisterCandidateLocal(final UnregisterCandidateLocal unregisterCandidate) {
LOG.debug("{}: onUnregisterCandidateLocal: {}", persistenceId(), unregisterCandidate);
DOMEntity entity = unregisterCandidate.getEntity();
YangInstanceIdentifier candidatePath = candidatePath(entity.getType(), entity.getIdentifier(),
localMemberName.getName());
commitCoordinator.commitModification(new DeleteModification(candidatePath), this);
getSender().tell(SuccessReply.INSTANCE, getSelf());
}
private void onRegisterListenerLocal(final RegisterListenerLocal registerListener) {
LOG.debug("{}: onRegisterListenerLocal: {}", persistenceId(), registerListener);
listenerSupport.addEntityOwnershipListener(registerListener.getEntityType(), registerListener.getListener());
getSender().tell(SuccessReply.INSTANCE, getSelf());
searchForEntities((entityTypeNode, entityNode) -> {
Optional<DataContainerChild<?, ?>> possibleType = entityTypeNode.getChild(ENTITY_TYPE_NODE_ID);
String entityType = possibleType.isPresent() ? possibleType.get().getValue().toString() : null;
if (registerListener.getEntityType().equals(entityType)) {
final boolean hasOwner;
final boolean isOwner;
Optional<DataContainerChild<?, ?>> possibleOwner = entityNode.getChild(ENTITY_OWNER_NODE_ID);
if (possibleOwner.isPresent()) {
isOwner = localMemberName.getName().equals(possibleOwner.get().getValue().toString());
hasOwner = true;
} else {
isOwner = false;
hasOwner = false;
}
DOMEntity entity = new DOMEntity(entityType,
(YangInstanceIdentifier) entityNode.getChild(ENTITY_ID_NODE_ID).get().getValue());
listenerSupport.notifyEntityOwnershipListener(entity, false, isOwner, hasOwner,
registerListener.getListener());
}
});
}
private void onUnregisterListenerLocal(final UnregisterListenerLocal unregisterListener) {
LOG.debug("{}: onUnregisterListenerLocal: {}", persistenceId(), unregisterListener);
listenerSupport.removeEntityOwnershipListener(unregisterListener.getEntityType(),
unregisterListener.getListener());
getSender().tell(SuccessReply.INSTANCE, getSelf());
}
void tryCommitModifications(final BatchedModifications modifications) {
if (isLeader()) {
LOG.debug("{}: Committing BatchedModifications {} locally", persistenceId(),
modifications.getTransactionId());
// Note that it's possible the commit won't get consensus and will timeout and not be applied
// to the state. However we don't need to retry it in that case b/c it will be committed to
// the journal first and, once a majority of followers come back on line and it is replicated,
// it will be applied at that point.
handleBatchedModificationsLocal(modifications, self());
} else {
final ActorSelection leader = getLeader();
if (leader != null) {
possiblyRemoveAllInitialCandidates(leader);
LOG.debug("{}: Sending BatchedModifications {} to leader {}", persistenceId(),
modifications.getTransactionId(), leader);
Future<Object> future = Patterns.ask(leader, modifications, TimeUnit.SECONDS.toMillis(
getDatastoreContext().getShardTransactionCommitTimeoutInSeconds()));
Patterns.pipe(future, getContext().dispatcher()).pipeTo(getSelf(), ActorRef.noSender());
}
}
}
void possiblyRemoveAllInitialCandidates(final ActorSelection leader) {
// The following handles removing all candidates on startup when re-joining with a remote leader. When a
// follower is detected as down, the leader will re-assign new owners to entities that were owned by the
// down member but doesn't remove the down member as a candidate, as the down node may actually be isolated
// and still running. Therefore on startup we send an initial message to the remote leader to remove any
// potential stale candidates we had previously registered, as it's possible a candidate may not be
// registered by a client in the new incarnation. We have to send the RemoveAllCandidates message prior to any
// pending registrations.
if (removeAllInitialCandidates && leader != null) {
removeAllInitialCandidates = false;
if (!isLeader()) {
LOG.debug("{} - got new leader {} on startup - sending RemoveAllCandidates", persistenceId(), leader);
leader.tell(new RemoveAllCandidates(localMemberName), ActorRef.noSender());
}
}
}
boolean hasLeader() {
return getLeader() != null && (!isLeader() || isLeaderActive());
}
/**
* Determine if we are in jeopardy based on observed RAFT state.
*/
private static boolean inJeopardy(final RaftState state) {
switch (state) {
case Candidate:
case Follower:
case Leader:
case PreLeader:
return false;
case IsolatedLeader:
return true;
default:
throw new IllegalStateException("Unsupported RAFT state " + state);
}
}
private void notifyAllListeners() {
searchForEntities((entityTypeNode, entityNode) -> {
Optional<DataContainerChild<?, ?>> possibleType = entityTypeNode.getChild(ENTITY_TYPE_NODE_ID);
if (possibleType.isPresent()) {
final boolean hasOwner;
final boolean isOwner;
Optional<DataContainerChild<?, ?>> possibleOwner = entityNode.getChild(ENTITY_OWNER_NODE_ID);
if (possibleOwner.isPresent()) {
isOwner = localMemberName.getName().equals(possibleOwner.get().getValue().toString());
hasOwner = true;
} else {
isOwner = false;
hasOwner = false;
}
DOMEntity entity = new DOMEntity(possibleType.get().getValue().toString(),
(YangInstanceIdentifier) entityNode.getChild(ENTITY_ID_NODE_ID).get().getValue());
listenerSupport.notifyEntityOwnershipListeners(entity, isOwner, isOwner, hasOwner);
}
});
}
@Override
protected void onStateChanged() {
boolean isLeader = isLeader();
LOG.debug("{}: onStateChanged: isLeader: {}, hasLeader: {}", persistenceId(), isLeader, hasLeader());
// Examine current RAFT state to see if we are in jeopardy, potentially notifying all listeners
final boolean inJeopardy = inJeopardy(getRaftState());
final boolean wasInJeopardy = listenerSupport.setInJeopardy(inJeopardy);
if (inJeopardy != wasInJeopardy) {
LOG.debug("{}: {} jeopardy state, notifying all listeners", persistenceId(),
inJeopardy ? "entered" : "left");
notifyAllListeners();
}
commitCoordinator.onStateChanged(this, isLeader);
super.onStateChanged();
}
@Override
protected void onLeaderChanged(final String oldLeader, final String newLeader) {
boolean isLeader = isLeader();
LOG.debug("{}: onLeaderChanged: oldLeader: {}, newLeader: {}, isLeader: {}", persistenceId(), oldLeader,
newLeader, isLeader);
if (isLeader) {
// Re-initialize the downPeerMemberNames from the current akka Cluster state. The previous leader, if any,
// is most likely down however it's possible we haven't received the PeerDown message yet.
initializeDownPeerMemberNamesFromClusterState();
// Clear all existing strategies so that they get re-created when we call createStrategy again
// This allows the strategies to be re-initialized with existing statistics maintained by
// EntityOwnershipStatistics
strategyConfig.clearStrategies();
// Re-assign owners for all members that are known to be down. In a cluster which has greater than
// 3 nodes it is possible for some node beside the leader being down when the leadership transitions
// it makes sense to use this event to re-assign owners for those downed nodes.
Set<String> ownedBy = new HashSet<>(downPeerMemberNames.size() + 1);
for (MemberName downPeerName : downPeerMemberNames) {
ownedBy.add(downPeerName.getName());
}
// Also try to assign owners for entities that have no current owner. See explanation in onPeerUp.
ownedBy.add("");
selectNewOwnerForEntitiesOwnedBy(ownedBy);
} else {
// The leader changed - notify the coordinator to check if pending modifications need to be sent.
// While onStateChanged also does this, this method handles the case where the shard hears from a
// leader and stays in the follower state. In that case no behavior state change occurs.
commitCoordinator.onStateChanged(this, isLeader);
}
super.onLeaderChanged(oldLeader, newLeader);
}
private void initializeDownPeerMemberNamesFromClusterState() {
java.util.Optional<Cluster> cluster = getRaftActorContext().getCluster();
if (!cluster.isPresent()) {
return;
}
CurrentClusterState state = cluster.get().state();
Set<Member> unreachable = state.getUnreachable();
LOG.debug(
"{}: initializeDownPeerMemberNamesFromClusterState - current downPeerMemberNames: {}, unreachable: {}",
persistenceId(), downPeerMemberNames, unreachable);
downPeerMemberNames.clear();
for (Member m: unreachable) {
downPeerMemberNames.add(MemberName.forName(m.getRoles().iterator().next()));
}
for (Member m: state.getMembers()) {
if (m.status() != MemberStatus.up() && m.status() != MemberStatus.weaklyUp()) {
LOG.debug("{}: Adding down member with status {}", persistenceId(), m.status());
downPeerMemberNames.add(MemberName.forName(m.getRoles().iterator().next()));
}
}
LOG.debug("{}: new downPeerMemberNames: {}", persistenceId(), downPeerMemberNames);
}
private void onCandidateRemoved(final CandidateRemoved message) {
LOG.debug("{}: onCandidateRemoved: {}", persistenceId(), message);
if (isLeader()) {
String currentOwner = getCurrentOwner(message.getEntityPath());
writeNewOwner(message.getEntityPath(),
newOwner(currentOwner, message.getRemainingCandidates(),
getEntityOwnerElectionStrategy(message.getEntityPath())));
}
}
private EntityOwnerSelectionStrategy getEntityOwnerElectionStrategy(final YangInstanceIdentifier entityPath) {
final String entityType = EntityOwnersModel.entityTypeFromEntityPath(entityPath);
return strategyConfig.createStrategy(entityType, entityOwnershipStatistics.byEntityType(entityType));
}
private void onCandidateAdded(final CandidateAdded message) {
if (!isLeader()) {
return;
}
LOG.debug("{}: onCandidateAdded: {}", persistenceId(), message);
// Since a node's candidate member is only added by the node itself, we can assume the node is up so
// remove it from the downPeerMemberNames.
downPeerMemberNames.remove(MemberName.forName(message.getNewCandidate()));
final String currentOwner = getCurrentOwner(message.getEntityPath());
final EntityOwnerSelectionStrategy strategy = getEntityOwnerElectionStrategy(message.getEntityPath());
// Available members is all the known peers - the number of peers that are down + self
// So if there are 2 peers and 1 is down then availableMembers will be 2
final int availableMembers = getRaftActorContext().getPeerIds().size() - downPeerMemberNames.size() + 1;
LOG.debug("{}: Using strategy {} to select owner, currentOwner = {}", persistenceId(), strategy, currentOwner);
if (strategy.getSelectionDelayInMillis() == 0L) {
writeNewOwner(message.getEntityPath(), newOwner(currentOwner, message.getAllCandidates(),
strategy));
} else if (message.getAllCandidates().size() == availableMembers) {
LOG.debug("{}: Received the maximum candidates requests : {} writing new owner",
persistenceId(), availableMembers);
cancelOwnerSelectionTask(message.getEntityPath());
writeNewOwner(message.getEntityPath(), newOwner(currentOwner, message.getAllCandidates(),
strategy));
} else {
scheduleOwnerSelection(message.getEntityPath(), message.getAllCandidates(), strategy);
}
}
private void onPeerDown(final PeerDown peerDown) {
LOG.info("{}: onPeerDown: {}", persistenceId(), peerDown);
MemberName downMemberName = peerDown.getMemberName();
if (downPeerMemberNames.add(downMemberName) && isLeader()) {
// Select new owners for entities owned by the down peer and which have other candidates. For an entity for
// which the down peer is the only candidate, we leave it as the owner and don't clear it. This is done to
// handle the case where the peer member process is actually still running but the node is partitioned.
// When the partition is healed, the peer just remains as the owner. If the peer process actually restarted,
// it will first remove all its candidates on startup. If another candidate is registered during the time
// the peer is down, the new candidate will be selected as the new owner.
selectNewOwnerForEntitiesOwnedBy(ImmutableSet.of(downMemberName.getName()));
}
}
private void selectNewOwnerForEntitiesOwnedBy(final Set<String> ownedBy) {
final BatchedModifications modifications = commitCoordinator.newBatchedModifications();
searchForEntitiesOwnedBy(ownedBy, (entityTypeNode, entityNode) -> {
YangInstanceIdentifier entityPath = YangInstanceIdentifier.builder(ENTITY_TYPES_PATH)
.node(entityTypeNode.getIdentifier()).node(ENTITY_NODE_ID).node(entityNode.getIdentifier())
.node(ENTITY_OWNER_NODE_ID).build();
String newOwner = newOwner(getCurrentOwner(entityPath), getCandidateNames(entityNode),
getEntityOwnerElectionStrategy(entityPath));
if (!newOwner.isEmpty()) {
LOG.debug("{}: Found entity {}, writing new owner {}", persistenceId(), entityPath, newOwner);
modifications.addModification(new WriteModification(entityPath,
ImmutableNodes.leafNode(ENTITY_OWNER_NODE_ID, newOwner)));
} else {
LOG.debug("{}: Found entity {} but no other candidates - not clearing owner", persistenceId(),
entityPath, newOwner);
}
});
commitCoordinator.commitModifications(modifications, this);
}
private void onPeerUp(final PeerUp peerUp) {
LOG.debug("{}: onPeerUp: {}", persistenceId(), peerUp);
downPeerMemberNames.remove(peerUp.getMemberName());
// Notify the coordinator to check if pending modifications need to be sent. We do this here
// to handle the case where the leader's peer address isn't known yet when a prior state or
// leader change occurred.
commitCoordinator.onStateChanged(this, isLeader());
if (isLeader()) {
// Try to assign owners for entities that have no current owner. It's possible the peer that is now up
// had previously registered as a candidate and was the only candidate but the owner write tx couldn't be
// committed due to a leader change. Eg, the leader is able to successfully commit the candidate add tx but
// becomes isolated before it can commit the owner change and switches to follower. The majority partition
// with a new leader has the candidate but the entity has no owner. When the partition is healed and the
// previously isolated leader reconnects, we'll receive onPeerUp and, if there's still no owner, the
// previous leader will gain ownership.
selectNewOwnerForEntitiesOwnedBy(ImmutableSet.of(""));
}
}
private static Collection<String> getCandidateNames(final MapEntryNode entity) {
Collection<MapEntryNode> candidates = ((MapNode)entity.getChild(CANDIDATE_NODE_ID).get()).getValue();
Collection<String> candidateNames = new ArrayList<>(candidates.size());
for (MapEntryNode candidate: candidates) {
candidateNames.add(candidate.getChild(CANDIDATE_NAME_NODE_ID).get().getValue().toString());
}
return candidateNames;
}
private void searchForEntitiesOwnedBy(final Set<String> ownedBy, final EntityWalker walker) {
LOG.debug("{}: Searching for entities owned by {}", persistenceId(), ownedBy);
searchForEntities((entityTypeNode, entityNode) -> {
Optional<DataContainerChild<? extends PathArgument, ?>> possibleOwner =
entityNode.getChild(ENTITY_OWNER_NODE_ID);
String currentOwner = possibleOwner.isPresent() ? possibleOwner.get().getValue().toString() : "";
if (ownedBy.contains(currentOwner)) {
walker.onEntity(entityTypeNode, entityNode);
}
});
}
private void removeCandidateFromEntities(final MemberName member) {
final BatchedModifications modifications = commitCoordinator.newBatchedModifications();
searchForEntities((entityTypeNode, entityNode) -> {
if (hasCandidate(entityNode, member)) {
YangInstanceIdentifier entityId =
(YangInstanceIdentifier) entityNode.getIdentifier().getKeyValues().get(ENTITY_ID_QNAME);
YangInstanceIdentifier candidatePath = candidatePath(
entityTypeNode.getIdentifier().getKeyValues().get(ENTITY_TYPE_QNAME).toString(),
entityId, member.getName());
LOG.info("{}: Found entity {}, removing candidate {}, path {}", persistenceId(), entityId,
member, candidatePath);
modifications.addModification(new DeleteModification(candidatePath));
}
});
commitCoordinator.commitModifications(modifications, this);
}
private static boolean hasCandidate(final MapEntryNode entity, final MemberName candidateName) {
return ((MapNode)entity.getChild(CANDIDATE_NODE_ID).get()).getChild(candidateNodeKey(candidateName.getName()))
.isPresent();
}
private void searchForEntities(final EntityWalker walker) {
Optional<NormalizedNode<?, ?>> possibleEntityTypes = getDataStore().readNode(ENTITY_TYPES_PATH);
if (!possibleEntityTypes.isPresent()) {
return;
}
for (MapEntryNode entityType: ((MapNode) possibleEntityTypes.get()).getValue()) {
Optional<DataContainerChild<?, ?>> possibleEntities = entityType.getChild(ENTITY_NODE_ID);
if (!possibleEntities.isPresent()) {
// shouldn't happen but handle anyway
continue;
}
for (MapEntryNode entity: ((MapNode) possibleEntities.get()).getValue()) {
walker.onEntity(entityType, entity);
}
}
}
private void writeNewOwner(final YangInstanceIdentifier entityPath, final String newOwner) {
LOG.debug("{}: Writing new owner {} for entity {}", persistenceId(), newOwner, entityPath);
commitCoordinator.commitModification(new WriteModification(entityPath.node(ENTITY_OWNER_QNAME),
ImmutableNodes.leafNode(ENTITY_OWNER_NODE_ID, newOwner)), this);
}
/**
* Schedule a new owner selection job. Cancelling any outstanding job if it has not been cancelled.
*/
private void scheduleOwnerSelection(final YangInstanceIdentifier entityPath, final Collection<String> allCandidates,
final EntityOwnerSelectionStrategy strategy) {
cancelOwnerSelectionTask(entityPath);
LOG.debug("{}: Scheduling owner selection after {} ms", persistenceId(), strategy.getSelectionDelayInMillis());
final Cancellable lastScheduledTask = context().system().scheduler().scheduleOnce(
FiniteDuration.apply(strategy.getSelectionDelayInMillis(), TimeUnit.MILLISECONDS), self(),
new SelectOwner(entityPath, allCandidates, strategy), context().system().dispatcher(), self());
entityToScheduledOwnershipTask.put(entityPath, lastScheduledTask);
}
private void cancelOwnerSelectionTask(final YangInstanceIdentifier entityPath) {
final Cancellable lastScheduledTask = entityToScheduledOwnershipTask.get(entityPath);
if (lastScheduledTask != null && !lastScheduledTask.isCancelled()) {
lastScheduledTask.cancel();
}
}
private String newOwner(final String currentOwner, final Collection<String> candidates,
final EntityOwnerSelectionStrategy ownerSelectionStrategy) {
Collection<String> viableCandidates = getViableCandidates(candidates);
if (viableCandidates.isEmpty()) {
return "";
}
return ownerSelectionStrategy.newOwner(currentOwner, viableCandidates);
}
private Collection<String> getViableCandidates(final Collection<String> candidates) {
Collection<String> viableCandidates = new ArrayList<>();
for (String candidate : candidates) {
if (!downPeerMemberNames.contains(MemberName.forName(candidate))) {
viableCandidates.add(candidate);
}
}
return viableCandidates;
}
private String getCurrentOwner(final YangInstanceIdentifier entityId) {
Optional<NormalizedNode<?, ?>> optionalEntityOwner = getDataStore().readNode(entityId.node(ENTITY_OWNER_QNAME));
if (optionalEntityOwner.isPresent()) {
return optionalEntityOwner.get().getValue().toString();
}
return null;
}
@FunctionalInterface
private interface EntityWalker {
void onEntity(MapEntryNode entityTypeNode, MapEntryNode entityNode);
}
public static Builder newBuilder() {
return new Builder();
}
static class Builder extends Shard.AbstractBuilder<Builder, EntityOwnershipShard> {
private MemberName localMemberName;
private EntityOwnerSelectionStrategyConfig ownerSelectionStrategyConfig;
protected Builder() {
super(EntityOwnershipShard.class);
}
Builder localMemberName(final MemberName newLocalMemberName) {
checkSealed();
this.localMemberName = newLocalMemberName;
return this;
}
Builder ownerSelectionStrategyConfig(final EntityOwnerSelectionStrategyConfig newOwnerSelectionStrategyConfig) {
checkSealed();
this.ownerSelectionStrategyConfig = newOwnerSelectionStrategyConfig;
return this;
}
@Override
protected void verify() {
super.verify();
Preconditions.checkNotNull(localMemberName, "localMemberName should not be null");
Preconditions.checkNotNull(ownerSelectionStrategyConfig, "ownerSelectionStrategyConfig should not be null");
}
}
}