X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-distributed-datastore%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fcluster%2Fdatastore%2Fentityownership%2FEntityOwnershipShard.java;h=46743482928f92bc1e44f28c0df8c27923d8f721;hp=629f9382a1b754c0088e5f7cab8a2474851ac9d9;hb=d86f990976dcc2879b40dec7df1b3b5fba8cba78;hpb=00e97ff87662959a39218b47bac904235003dc8d diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/entityownership/EntityOwnershipShard.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/entityownership/EntityOwnershipShard.java index 629f9382a1..4674348292 100644 --- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/entityownership/EntityOwnershipShard.java +++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/entityownership/EntityOwnershipShard.java @@ -7,35 +7,65 @@ */ package org.opendaylight.controller.cluster.datastore.entityownership; +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.candidateMapEntry; +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.createEntity; import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.entityOwnersWithCandidate; import akka.actor.ActorRef; import akka.actor.ActorSelection; -import akka.actor.Props; +import akka.actor.Cancellable; import akka.pattern.Patterns; import com.google.common.base.Optional; +import com.google.common.base.Preconditions; +import com.google.common.base.Strings; +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.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.identifiers.ShardIdentifier; 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.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.api.schema.tree.DataTreeSnapshot; import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes; -import org.opendaylight.yangtools.yang.model.api.SchemaContext; import scala.concurrent.Future; +import scala.concurrent.duration.FiniteDuration; /** * Special Shard for EntityOwnership. @@ -43,18 +73,32 @@ import scala.concurrent.Future; * @author Thomas Pantelis */ class EntityOwnershipShard extends Shard { - private final String localMemberName; + private final MemberName localMemberName; private final EntityOwnershipShardCommitCoordinator commitCoordinator; + private final EntityOwnershipListenerSupport listenerSupport; + private final Set downPeerMemberNames = new HashSet<>(); + private final Map peerIdToMemberNames = new HashMap<>(); + private final EntityOwnerSelectionStrategyConfig strategyConfig; + private final Map entityToScheduledOwnershipTask = new HashMap<>(); + private final EntityOwnershipStatistics entityOwnershipStatistics; private static DatastoreContext noPersistenceDatastoreContext(DatastoreContext datastoreContext) { return DatastoreContext.newBuilderFrom(datastoreContext).persistent(false).build(); } - protected EntityOwnershipShard(ShardIdentifier name, Map peerAddresses, - DatastoreContext datastoreContext, SchemaContext schemaContext, String localMemberName) { - super(name, peerAddresses, noPersistenceDatastoreContext(datastoreContext), schemaContext); - this.localMemberName = localMemberName; - this.commitCoordinator = new EntityOwnershipShardCommitCoordinator(localMemberName, LOG); + protected EntityOwnershipShard(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()); + + for(String peerId: getRaftActorContext().getPeerIds()) { + ShardIdentifier shardId = ShardIdentifier.fromShardIdString(peerId); + peerIdToMemberNames.put(peerId, shardId.getMemberName()); + } } @Override @@ -66,39 +110,122 @@ class EntityOwnershipShard extends Shard { protected void onRecoveryComplete() { super.onRecoveryComplete(); - new CandidateListChangeListener(getSelf(), getDataStore()); + new CandidateListChangeListener(getSelf(), persistenceId()).init(getDataStore()); + new EntityOwnerChangeListener(localMemberName, listenerSupport).init(getDataStore()); } @Override - public void onReceiveCommand(final Object message) throws Exception { + public void handleNonRaftCommand(final Object message) { if(message instanceof RegisterCandidateLocal) { - onRegisterCandidateLocal((RegisterCandidateLocal)message); + 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(!commitCoordinator.handleMessage(message, this)) { - super.onReceiveCommand(message); + super.handleNonRaftCommand(message); + } + } + + private void onSelectOwner(SelectOwner selectOwner) { + LOG.debug("{}: onSelectOwner: {}", persistenceId(), selectOwner); + + String currentOwner = getCurrentOwner(selectOwner.getEntityPath()); + if(Strings.isNullOrEmpty(currentOwner)) { + String entityType = EntityOwnersModel.entityTypeFromEntityPath(selectOwner.getEntityPath()); + writeNewOwner(selectOwner.getEntityPath(), newOwner(currentOwner, selectOwner.getAllCandidates(), + entityOwnershipStatistics.byEntityType(entityType), + selectOwner.getOwnerSelectionStrategy())); + + Cancellable cancellable = entityToScheduledOwnershipTask.get(selectOwner.getEntityPath()); + if(cancellable != null){ + if(!cancellable.isCancelled()){ + cancellable.cancel(); + } + entityToScheduledOwnershipTask.remove(selectOwner.getEntityPath()); + } } } private void onRegisterCandidateLocal(RegisterCandidateLocal registerCandidate) { - LOG.debug("onRegisterCandidateLocal: {}", registerCandidate); + LOG.debug("{}: onRegisterCandidateLocal: {}", persistenceId(), registerCandidate); - // TODO - add the listener locally. + listenerSupport.setHasCandidateForEntity(registerCandidate.getEntity()); NormalizedNode entityOwners = entityOwnersWithCandidate(registerCandidate.getEntity().getType(), - registerCandidate.getEntity().getId(), localMemberName); + registerCandidate.getEntity().getIdentifier(), localMemberName.getName()); commitCoordinator.commitModification(new MergeModification(ENTITY_OWNERS_PATH, entityOwners), this); getSender().tell(SuccessReply.INSTANCE, getSelf()); } + private void onUnregisterCandidateLocal(UnregisterCandidateLocal unregisterCandidate) { + LOG.debug("{}: onUnregisterCandidateLocal: {}", persistenceId(), unregisterCandidate); + + DOMEntity entity = unregisterCandidate.getEntity(); + listenerSupport.unsetHasCandidateForEntity(entity); + + 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> 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> 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(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", modifications.getTransactionID()); + 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 @@ -108,7 +235,10 @@ class EntityOwnershipShard extends Shard { } else { final ActorSelection leader = getLeader(); if (leader != null) { - LOG.debug("Sending BatchedModifications {} to leader {}", modifications.getTransactionID(), leader); + if(LOG.isDebugEnabled()) { + LOG.debug("{}: Sending BatchedModifications {} to leader {}", persistenceId(), + modifications.getTransactionID(), leader); + } Future future = Patterns.ask(leader, modifications, TimeUnit.SECONDS.toMillis( getDatastoreContext().getShardTransactionCommitTimeoutInSeconds())); @@ -122,88 +252,325 @@ class EntityOwnershipShard extends Shard { return getLeader() != null && !isIsolatedLeader(); } + /** + * 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; + } + throw new IllegalStateException("Unsupported RAFT state " + state); + } + + private void notifyAllListeners() { + searchForEntities((entityTypeNode, entityNode) -> { + Optional> possibleType = entityTypeNode.getChild(ENTITY_TYPE_NODE_ID); + if (possibleType.isPresent()) { + final boolean hasOwner; + final boolean isOwner; + + Optional> 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() { super.onStateChanged(); - commitCoordinator.onStateChanged(this, isLeader()); + 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); } - private void onUnregisterCandidateLocal(UnregisterCandidateLocal unregisterCandidate) { - // TODO - implement - getSender().tell(SuccessReply.INSTANCE, getSelf()); + @Override + protected void onLeaderChanged(String oldLeader, String newLeader) { + super.onLeaderChanged(oldLeader, newLeader); + + boolean isLeader = isLeader(); + LOG.debug("{}: onLeaderChanged: oldLeader: {}, newLeader: {}, isLeader: {}", persistenceId(), oldLeader, + newLeader, isLeader); + + if (isLeader) { + + // 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(); + + // Remove the candidates for all members that are known to be down. In a cluster which has greater than + // 3 nodes it is possible for a some node beside the leader being down when the leadership transitions + // it makes sense to use this event to remove all the candidates for those downed nodes + for (MemberName downPeerName : downPeerMemberNames) { + removeCandidateFromEntities(downPeerName); + } + } 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); + } } private void onCandidateRemoved(CandidateRemoved message) { + LOG.debug("{}: onCandidateRemoved: {}", persistenceId(), message); + + if(isLeader()) { + String currentOwner = getCurrentOwner(message.getEntityPath()); + if(message.getRemovedCandidate().equals(currentOwner) || message.getRemainingCandidates().size() == 0){ + String entityType = EntityOwnersModel.entityTypeFromEntityPath(message.getEntityPath()); + writeNewOwner(message.getEntityPath(), + newOwner(currentOwner, message.getRemainingCandidates(), entityOwnershipStatistics.byEntityType(entityType), + getEntityOwnerElectionStrategy(message.getEntityPath()))); + } + } else { + // We're not the leader. If the removed candidate is our local member then check if we actually + // have a local candidate registered. If we do then we must have been partitioned from the leader + // and the leader removed our candidate since the leader can't tell the difference between a + // temporary network partition and a node's process actually restarted. So, in that case, re-add + // our candidate. + if(localMemberName.getName().equals(message.getRemovedCandidate()) && + listenerSupport.hasCandidateForEntity(createEntity(message.getEntityPath()))) { + LOG.debug("Local candidate member was removed but a local candidate is registered for {}" + + " - adding back local candidate", message.getEntityPath()); + + commitCoordinator.commitModification(new MergeModification( + candidatePath(message.getEntityPath(), localMemberName.getName()), + candidateMapEntry(localMemberName.getName())), this); + } + } + } + + private EntityOwnerSelectionStrategy getEntityOwnerElectionStrategy(YangInstanceIdentifier entityPath) { + final String entityType = EntityOwnersModel.entityTypeFromEntityPath(entityPath); + return strategyConfig.createStrategy(entityType, entityOwnershipStatistics.byEntityType(entityType)); + } + + private void onCandidateAdded(CandidateAdded message) { if(!isLeader()){ return; } - LOG.debug("onCandidateRemoved: {}", message); + 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(message.getNewCandidate()); + + final String currentOwner = getCurrentOwner(message.getEntityPath()); + final EntityOwnerSelectionStrategy strategy = getEntityOwnerElectionStrategy(message.getEntityPath()); + final String entityType = EntityOwnersModel.entityTypeFromEntityPath(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 = (peerIdToMemberNames.size() - downPeerMemberNames.size()) + 1; + + LOG.debug("{}: Using strategy {} to select owner, currentOwner = {}", persistenceId(), strategy, currentOwner); + + if(!message.getAllCandidates().contains(currentOwner)){ + if(strategy.getSelectionDelayInMillis() == 0L) { + writeNewOwner(message.getEntityPath(), newOwner(currentOwner, message.getAllCandidates(), + entityOwnershipStatistics.byEntityType(entityType), 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(), + entityOwnershipStatistics.byEntityType(entityType), strategy)); + } else { + scheduleOwnerSelection(message.getEntityPath(), message.getAllCandidates(), strategy); + } + } + } + + private void onPeerDown(PeerDown peerDown) { + LOG.info("{}: onPeerDown: {}", persistenceId(), peerDown); - String currentOwner = getCurrentOwner(message.getEntityPath()); - if(message.getRemovedCandidate().equals(currentOwner)){ - writeNewOwner(message.getEntityPath(), newOwner(message.getRemainingCandidates())); + MemberName downMemberName = peerDown.getMemberName(); + if(downPeerMemberNames.add(downMemberName) && isLeader()) { + // Remove the down peer as a candidate from all entities. + removeCandidateFromEntities(downMemberName); } } - private void onCandidateAdded(CandidateAdded message) { - if(!isLeader()){ + private void onPeerUp(PeerUp peerUp) { + LOG.debug("{}: onPeerUp: {}", persistenceId(), peerUp); + + peerIdToMemberNames.put(peerUp.getPeerId(), peerUp.getMemberName()); + 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 now yet when a prior state or + // leader change occurred. + commitCoordinator.onStateChanged(this, isLeader()); + } + + private void removeCandidateFromEntities(final MemberName owner) { + final BatchedModifications modifications = commitCoordinator.newBatchedModifications(); + searchForEntities((entityTypeNode, entityNode) -> { + if (hasCandidate(entityNode, owner)) { + YangInstanceIdentifier entityId = + (YangInstanceIdentifier) entityNode.getIdentifier().getKeyValues().get(ENTITY_ID_QNAME); + YangInstanceIdentifier candidatePath = candidatePath( + entityTypeNode.getIdentifier().getKeyValues().get(ENTITY_TYPE_QNAME).toString(), + entityId, owner.getName()); + + LOG.info("{}: Found entity {}, removing candidate {}, path {}", persistenceId(), entityId, + owner, candidatePath); + + modifications.addModification(new DeleteModification(candidatePath)); + } + }); + + commitCoordinator.commitModifications(modifications, this); + } + + private static boolean hasCandidate(MapEntryNode entity, MemberName candidateName) { + return ((MapNode)entity.getChild(CANDIDATE_NODE_ID).get()).getChild(candidateNodeKey(candidateName.getName())) + .isPresent(); + } + + private void searchForEntities(EntityWalker walker) { + Optional> possibleEntityTypes = getDataStore().readNode(ENTITY_TYPES_PATH); + if(!possibleEntityTypes.isPresent()) { return; } - LOG.debug("onCandidateAdded: {}", message); + for(MapEntryNode entityType: ((MapNode) possibleEntityTypes.get()).getValue()) { + Optional> possibleEntities = entityType.getChild(ENTITY_NODE_ID); + if(!possibleEntities.isPresent()) { + // shouldn't happen but handle anyway + continue; + } - String currentOwner = getCurrentOwner(message.getEntityPath()); - if(currentOwner == null){ - writeNewOwner(message.getEntityPath(), newOwner(message.getAllCandidates())); + for(MapEntryNode entity: ((MapNode) possibleEntities.get()).getValue()) { + walker.onEntity(entityType, entity); + } } } private void writeNewOwner(YangInstanceIdentifier entityPath, String newOwner) { - LOG.debug("Writing new owner {} for entity {}", newOwner, entityPath); + 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); } - private String newOwner(Collection candidates) { - if(candidates.size() > 0){ - return candidates.iterator().next(); + /** + * Schedule a new owner selection job. Cancelling any outstanding job if it has not been cancelled. + * + * @param entityPath + * @param allCandidates + */ + public void scheduleOwnerSelection(YangInstanceIdentifier entityPath, Collection allCandidates, + 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(YangInstanceIdentifier entityPath){ + final Cancellable lastScheduledTask = entityToScheduledOwnershipTask.get(entityPath); + if(lastScheduledTask != null && !lastScheduledTask.isCancelled()){ + lastScheduledTask.cancel(); } + } - return ""; + private String newOwner(String currentOwner, Collection candidates, Map statistics, EntityOwnerSelectionStrategy ownerSelectionStrategy) { + Collection viableCandidates = getViableCandidates(candidates); + if(viableCandidates.size() == 0){ + return ""; + } + return ownerSelectionStrategy.newOwner(currentOwner, viableCandidates); + } + + private Collection getViableCandidates(Collection candidates) { + Collection viableCandidates = new ArrayList<>(); + + for (String candidate : candidates) { + if (!downPeerMemberNames.contains(candidate)) { + viableCandidates.add(candidate); + } + } + return viableCandidates; } private String getCurrentOwner(YangInstanceIdentifier entityId) { - DataTreeSnapshot snapshot = getDataStore().getDataTree().takeSnapshot(); - Optional> optionalEntityOwner = snapshot.readNode(entityId.node(ENTITY_OWNER_QNAME)); + Optional> optionalEntityOwner = getDataStore().readNode(entityId.node(ENTITY_OWNER_QNAME)); if(optionalEntityOwner.isPresent()){ return optionalEntityOwner.get().getValue().toString(); } return null; } - public static Props props(final ShardIdentifier name, final Map peerAddresses, - final DatastoreContext datastoreContext, final SchemaContext schemaContext, final String localMemberName) { - return Props.create(new Creator(name, peerAddresses, datastoreContext, schemaContext, localMemberName)); + private static interface EntityWalker { + void onEntity(MapEntryNode entityTypeNode, MapEntryNode entityNode); } - private static class Creator extends AbstractShardCreator { - private static final long serialVersionUID = 1L; + public static Builder newBuilder() { + return new Builder(); + } + + static class Builder extends Shard.AbstractBuilder { + private MemberName localMemberName; + private EntityOwnerSelectionStrategyConfig ownerSelectionStrategyConfig; - private final String localMemberName; + protected Builder() { + super(EntityOwnershipShard.class); + } - Creator(final ShardIdentifier name, final Map peerAddresses, - final DatastoreContext datastoreContext, final SchemaContext schemaContext, - final String localMemberName) { - super(name, peerAddresses, datastoreContext, schemaContext); + Builder localMemberName(MemberName localMemberName) { + checkSealed(); this.localMemberName = localMemberName; + return this; + } + + Builder ownerSelectionStrategyConfig(EntityOwnerSelectionStrategyConfig ownerSelectionStrategyConfig){ + checkSealed(); + this.ownerSelectionStrategyConfig = ownerSelectionStrategyConfig; + return this; } @Override - public Shard create() throws Exception { - return new EntityOwnershipShard(name, peerAddresses, datastoreContext, schemaContext, localMemberName); + protected void verify() { + super.verify(); + Preconditions.checkNotNull(localMemberName, "localMemberName should not be null"); + Preconditions.checkNotNull(ownerSelectionStrategyConfig, "ownerSelectionStrategyConfig should not be null"); } } }