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%2FShardManager.java;h=a91109c64b3fa5aac674677b95d2a31c83477fbd;hp=2f6bb464c673b0fb06d978d7b3d5c9187806620d;hb=d4d59200f8c56551755c36fbbd2b4aa52defa5cb;hpb=92edfd0e7e15de0f3b8ad089c45ea91812fae867 diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardManager.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardManager.java index 2f6bb464c6..a91109c64b 100644 --- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardManager.java +++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardManager.java @@ -16,12 +16,16 @@ import akka.actor.Cancellable; import akka.actor.OneForOneStrategy; import akka.actor.PoisonPill; import akka.actor.Props; +import akka.actor.Status; import akka.actor.SupervisorStrategy; import akka.cluster.ClusterEvent; import akka.dispatch.OnComplete; -import akka.japi.Creator; import akka.japi.Function; import akka.persistence.RecoveryCompleted; +import akka.persistence.SaveSnapshotFailure; +import akka.persistence.SaveSnapshotSuccess; +import akka.persistence.SnapshotOffer; +import akka.persistence.SnapshotSelectionCriteria; import akka.serialization.Serialization; import akka.util.Timeout; import com.google.common.annotations.VisibleForTesting; @@ -31,19 +35,28 @@ import com.google.common.base.Preconditions; import com.google.common.base.Strings; import com.google.common.base.Supplier; import com.google.common.collect.Sets; +import java.io.ByteArrayInputStream; +import java.io.ObjectInputStream; import java.io.Serializable; import java.util.ArrayList; import java.util.Collection; +import java.util.Collections; import java.util.HashMap; +import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; import java.util.concurrent.CountDownLatch; import java.util.concurrent.TimeUnit; +import java.util.concurrent.TimeoutException; +import javax.annotation.Nonnull; +import javax.annotation.Nullable; +import org.apache.commons.lang3.SerializationUtils; import org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActorWithMetering; import org.opendaylight.controller.cluster.datastore.config.Configuration; import org.opendaylight.controller.cluster.datastore.config.ModuleShardConfiguration; +import org.opendaylight.controller.cluster.datastore.exceptions.AlreadyExistsException; import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException; import org.opendaylight.controller.cluster.datastore.exceptions.NotInitializedException; import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException; @@ -53,7 +66,7 @@ import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shardmanager.Sha import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized; import org.opendaylight.controller.cluster.datastore.messages.AddShardReplica; import org.opendaylight.controller.cluster.datastore.messages.CreateShard; -import org.opendaylight.controller.cluster.datastore.messages.CreateShardReply; +import org.opendaylight.controller.cluster.datastore.messages.DatastoreSnapshot; import org.opendaylight.controller.cluster.datastore.messages.FindLocalShard; import org.opendaylight.controller.cluster.datastore.messages.FindPrimary; import org.opendaylight.controller.cluster.datastore.messages.LocalPrimaryShardFound; @@ -78,7 +91,10 @@ import org.opendaylight.controller.cluster.raft.base.messages.SwitchBehavior; import org.opendaylight.controller.cluster.raft.client.messages.GetSnapshot; import org.opendaylight.controller.cluster.raft.messages.AddServer; import org.opendaylight.controller.cluster.raft.messages.AddServerReply; +import org.opendaylight.controller.cluster.raft.messages.RemoveServer; +import org.opendaylight.controller.cluster.raft.messages.RemoveServerReply; import org.opendaylight.controller.cluster.raft.messages.ServerChangeStatus; +import org.opendaylight.controller.cluster.raft.messages.ServerRemoved; import org.opendaylight.controller.cluster.raft.policy.DisableElectionsRaftPolicy; import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree; import org.opendaylight.yangtools.yang.model.api.SchemaContext; @@ -116,7 +132,7 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { private final String shardDispatcherPath; - private ShardManagerInfo mBean; + private final ShardManagerInfo mBean; private DatastoreContextFactory datastoreContextFactory; @@ -128,43 +144,42 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { private SchemaContext schemaContext; + private DatastoreSnapshot restoreFromSnapshot; + + private ShardManagerSnapshot currentSnapshot; + + private final Set shardReplicaOperationsInProgress = new HashSet<>(); + + private final String persistenceId; + /** */ - protected ShardManager(ClusterWrapper cluster, Configuration configuration, - DatastoreContextFactory datastoreContextFactory, CountDownLatch waitTillReadyCountdownLatch, - PrimaryShardInfoFutureCache primaryShardInfoCache) { - - this.cluster = Preconditions.checkNotNull(cluster, "cluster should not be null"); - this.configuration = Preconditions.checkNotNull(configuration, "configuration should not be null"); - this.datastoreContextFactory = datastoreContextFactory; - this.type = datastoreContextFactory.getBaseDatastoreContext().getDataStoreType(); + protected ShardManager(AbstractBuilder builder) { + + this.cluster = builder.cluster; + this.configuration = builder.configuration; + this.datastoreContextFactory = builder.datastoreContextFactory; + this.type = builder.datastoreContextFactory.getBaseDatastoreContext().getDataStoreName(); this.shardDispatcherPath = new Dispatchers(context().system().dispatchers()).getDispatcherPath(Dispatchers.DispatcherType.Shard); - this.waitTillReadyCountdownLatch = waitTillReadyCountdownLatch; - this.primaryShardInfoCache = primaryShardInfoCache; + this.waitTillReadyCountdownLatch = builder.waitTillReadyCountdownLatch; + this.primaryShardInfoCache = builder.primaryShardInfoCache; + this.restoreFromSnapshot = builder.restoreFromSnapshot; + + String possiblePersistenceId = datastoreContextFactory.getBaseDatastoreContext().getShardManagerPersistenceId(); + persistenceId = possiblePersistenceId != null ? possiblePersistenceId : "shard-manager-" + type; peerAddressResolver = new ShardPeerAddressResolver(type, cluster.getCurrentMemberName()); // Subscribe this actor to cluster member events cluster.subscribeToMemberEvents(getSelf()); - createLocalShards(); - } - - public static Props props( - final ClusterWrapper cluster, - final Configuration configuration, - final DatastoreContextFactory datastoreContextFactory, - final CountDownLatch waitTillReadyCountdownLatch, - final PrimaryShardInfoFutureCache primaryShardInfoCache) { - - Preconditions.checkNotNull(cluster, "cluster should not be null"); - Preconditions.checkNotNull(configuration, "configuration should not be null"); - Preconditions.checkNotNull(waitTillReadyCountdownLatch, "waitTillReadyCountdownLatch should not be null"); - Preconditions.checkNotNull(primaryShardInfoCache, "primaryShardInfoCache should not be null"); - - return Props.create(new ShardManagerCreator(cluster, configuration, datastoreContextFactory, - waitTillReadyCountdownLatch, primaryShardInfoCache)); + List localShardActorNames = new ArrayList<>(); + mBean = ShardManagerInfo.createShardManagerMBean(cluster.getCurrentMemberName(), + "shard-manager-" + this.type, + datastoreContextFactory.getBaseDatastoreContext().getDataStoreMXBeanType(), + localShardActorNames); + mBean.setShardManager(this); } @Override @@ -210,14 +225,107 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { onCreateShard((CreateShard)message); } else if(message instanceof AddShardReplica){ onAddShardReplica((AddShardReplica)message); - } else if(message instanceof RemoveShardReplica){ - onRemoveShardReplica((RemoveShardReplica)message); + } else if(message instanceof ForwardedAddServerReply) { + ForwardedAddServerReply msg = (ForwardedAddServerReply)message; + onAddServerReply(msg.shardInfo, msg.addServerReply, getSender(), msg.leaderPath, + msg.removeShardOnFailure); + } else if(message instanceof ForwardedAddServerFailure) { + ForwardedAddServerFailure msg = (ForwardedAddServerFailure)message; + onAddServerFailure(msg.shardName, msg.failureMessage, msg.failure, getSender(), msg.removeShardOnFailure); + } else if(message instanceof PrimaryShardFoundForContext) { + PrimaryShardFoundForContext primaryShardFoundContext = (PrimaryShardFoundForContext)message; + onPrimaryShardFoundContext(primaryShardFoundContext); + } else if(message instanceof RemoveShardReplica) { + onRemoveShardReplica((RemoveShardReplica) message); + } else if(message instanceof WrappedShardResponse){ + onWrappedShardResponse((WrappedShardResponse) message); } else if(message instanceof GetSnapshot) { onGetSnapshot(); + } else if(message instanceof ServerRemoved){ + onShardReplicaRemoved((ServerRemoved) message); + } else if (message instanceof SaveSnapshotSuccess) { + onSaveSnapshotSuccess((SaveSnapshotSuccess)message); + } else if (message instanceof SaveSnapshotFailure) { + LOG.error("{}: SaveSnapshotFailure received for saving snapshot of shards", + persistenceId(), ((SaveSnapshotFailure) message).cause()); } else { unknownMessage(message); } + } + + private void onWrappedShardResponse(WrappedShardResponse message) { + if (message.getResponse() instanceof RemoveServerReply) { + onRemoveServerReply(getSender(), message.getShardName(), (RemoveServerReply) message.getResponse()); + } + } + + private void onRemoveServerReply(ActorRef originalSender, String shardName, RemoveServerReply response) { + shardReplicaOperationsInProgress.remove(shardName); + originalSender.tell(new Status.Success(null), self()); + } + + private void onPrimaryShardFoundContext(PrimaryShardFoundForContext primaryShardFoundContext) { + if(primaryShardFoundContext.getContextMessage() instanceof AddShardReplica) { + addShard(primaryShardFoundContext.getShardName(), primaryShardFoundContext.getRemotePrimaryShardFound(), + getSender()); + } else if(primaryShardFoundContext.getContextMessage() instanceof RemoveShardReplica){ + removeShardReplica((RemoveShardReplica) primaryShardFoundContext.getContextMessage(), + primaryShardFoundContext.getShardName(), primaryShardFoundContext.getPrimaryPath(), getSender()); + } + } + + private void removeShardReplica(RemoveShardReplica contextMessage, final String shardName, final String primaryPath, + final ActorRef sender) { + if(isShardReplicaOperationInProgress(shardName, sender)) { + return; + } + + shardReplicaOperationsInProgress.add(shardName); + + final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName); + + final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build(); + + //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message + LOG.debug ("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(), + primaryPath, shardId); + + Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout(). + duration()); + Future futureObj = ask(getContext().actorSelection(primaryPath), + new RemoveServer(shardId.toString()), removeServerTimeout); + + futureObj.onComplete(new OnComplete() { + @Override + public void onComplete(Throwable failure, Object response) { + if (failure != null) { + String msg = String.format("RemoveServer request to leader %s for shard %s failed", + primaryPath, shardName); + + LOG.debug ("{}: {}", persistenceId(), msg, failure); + + // FAILURE + sender.tell(new Status.Failure(new RuntimeException(msg, failure)), self()); + } else { + // SUCCESS + self().tell(new WrappedShardResponse(shardName, response), sender); + } + } + }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client)); + } + private void onShardReplicaRemoved(ServerRemoved message) { + final ShardIdentifier shardId = new ShardIdentifier.Builder().fromShardIdString(message.getServerId()).build(); + final ShardInformation shardInformation = localShards.remove(shardId.getShardName()); + if(shardInformation == null) { + LOG.debug("{} : Shard replica {} is not present in list", persistenceId(), shardId.toString()); + return; + } else if(shardInformation.getActor() != null) { + LOG.debug("{} : Sending PoisonPill to Shard actor {}", persistenceId(), shardInformation.getActor()); + shardInformation.getActor().tell(PoisonPill.getInstance(), self()); + } + LOG.debug("{} : Local Shard replica for shard {} has been removed", persistenceId(), shardId.getShardName()); + persistShardList(); } private void onGetSnapshot() { @@ -241,6 +349,10 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { } byte[] shardManagerSnapshot = null; + if(currentSnapshot != null) { + shardManagerSnapshot = SerializationUtils.serialize(currentSnapshot); + } + ActorRef replyActor = getContext().actorOf(ShardManagerGetSnapshotReplyActor.props( new ArrayList<>(localShards.keySet()), type, shardManagerSnapshot , getSender(), persistenceId(), datastoreContextFactory.getBaseDatastoreContext().getShardInitializationTimeout().duration())); @@ -251,49 +363,77 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { } private void onCreateShard(CreateShard createShard) { + LOG.debug("{}: onCreateShard: {}", persistenceId(), createShard); + Object reply; try { - ModuleShardConfiguration moduleShardConfig = createShard.getModuleShardConfig(); - if(localShards.containsKey(moduleShardConfig.getShardName())) { - throw new IllegalStateException(String.format("Shard with name %s already exists", - moduleShardConfig.getShardName())); + String shardName = createShard.getModuleShardConfig().getShardName(); + if(localShards.containsKey(shardName)) { + LOG.debug("{}: Shard {} already exists", persistenceId(), shardName); + reply = new akka.actor.Status.Success(String.format("Shard with name %s already exists", shardName)); + } else { + doCreateShard(createShard); + reply = new akka.actor.Status.Success(null); } + } catch (Exception e) { + LOG.error("{}: onCreateShard failed", persistenceId(), e); + reply = new akka.actor.Status.Failure(e); + } - configuration.addModuleShardConfiguration(moduleShardConfig); + if(getSender() != null && !getContext().system().deadLetters().equals(getSender())) { + getSender().tell(reply, getSelf()); + } + } - ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), moduleShardConfig.getShardName()); - Map peerAddresses = getPeerAddresses(moduleShardConfig.getShardName()/*, - moduleShardConfig.getShardMemberNames()*/); + private void doCreateShard(CreateShard createShard) { + ModuleShardConfiguration moduleShardConfig = createShard.getModuleShardConfig(); + String shardName = moduleShardConfig.getShardName(); - LOG.debug("onCreateShard: shardId: {}, memberNames: {}. peerAddresses: {}", shardId, - moduleShardConfig.getShardMemberNames(), peerAddresses); + configuration.addModuleShardConfiguration(moduleShardConfig); - DatastoreContext shardDatastoreContext = createShard.getDatastoreContext(); - if(shardDatastoreContext == null) { - shardDatastoreContext = newShardDatastoreContext(moduleShardConfig.getShardName()); - } else { - shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext).shardPeerAddressResolver( - peerAddressResolver).build(); - } - - ShardInformation info = new ShardInformation(moduleShardConfig.getShardName(), shardId, peerAddresses, - shardDatastoreContext, createShard.getShardPropsCreator(), peerAddressResolver); - localShards.put(info.getShardName(), info); + DatastoreContext shardDatastoreContext = createShard.getDatastoreContext(); + if(shardDatastoreContext == null) { + shardDatastoreContext = newShardDatastoreContext(shardName); + } else { + shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext).shardPeerAddressResolver( + peerAddressResolver).build(); + } - mBean.addLocalShard(shardId.toString()); + ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName); - if(schemaContext != null) { - info.setActor(newShardActor(schemaContext, info)); - } + boolean shardWasInRecoveredSnapshot = currentSnapshot != null && + currentSnapshot.getShardList().contains(shardName); - reply = new CreateShardReply(); - } catch (Exception e) { - LOG.error("onCreateShard failed", e); - reply = new akka.actor.Status.Failure(e); + Map peerAddresses; + boolean isActiveMember; + if(shardWasInRecoveredSnapshot || configuration.getMembersFromShardName(shardName). + contains(cluster.getCurrentMemberName())) { + peerAddresses = getPeerAddresses(shardName); + isActiveMember = true; + } else { + // The local member is not in the static shard member configuration and the shard did not + // previously exist (ie !shardWasInRecoveredSnapshot). In this case we'll create + // the shard with no peers and with elections disabled so it stays as follower. A + // subsequent AddServer request will be needed to make it an active member. + isActiveMember = false; + peerAddresses = Collections.emptyMap(); + shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext). + customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build(); } - if(getSender() != null && !getContext().system().deadLetters().equals(getSender())) { - getSender().tell(reply, getSelf()); + LOG.debug("{} doCreateShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}", + persistenceId(), shardId, moduleShardConfig.getShardMemberNames(), peerAddresses, + isActiveMember); + + ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses, + shardDatastoreContext, createShard.getShardBuilder(), peerAddressResolver); + info.setActiveMember(isActiveMember); + localShards.put(info.getShardName(), info); + + mBean.addLocalShard(shardId.toString()); + + if(schemaContext != null) { + info.setActor(newShardActor(schemaContext, info)); } } @@ -438,12 +578,34 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { @Override protected void handleRecover(Object message) throws Exception { if (message instanceof RecoveryCompleted) { - LOG.info("Recovery complete : {}", persistenceId()); + onRecoveryCompleted(); + } else if (message instanceof SnapshotOffer) { + applyShardManagerSnapshot((ShardManagerSnapshot)((SnapshotOffer) message).snapshot()); + } + } - // We no longer persist SchemaContext modules so delete all the prior messages from the akka - // journal on upgrade from Helium. - deleteMessages(lastSequenceNr()); + private void onRecoveryCompleted() { + LOG.info("Recovery complete : {}", persistenceId()); + + // We no longer persist SchemaContext modules so delete all the prior messages from the akka + // journal on upgrade from Helium. + deleteMessages(lastSequenceNr()); + + if(currentSnapshot == null && restoreFromSnapshot != null && + restoreFromSnapshot.getShardManagerSnapshot() != null) { + try(ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream( + restoreFromSnapshot.getShardManagerSnapshot()))) { + ShardManagerSnapshot snapshot = (ShardManagerSnapshot) ois.readObject(); + + LOG.debug("{}: Deserialized restored ShardManagerSnapshot: {}", persistenceId(), snapshot); + + applyShardManagerSnapshot(snapshot); + } catch(Exception e) { + LOG.error("{}: Error deserializing restored ShardManagerSnapshot", persistenceId(), e); + } } + + createLocalShards(); } private void findLocalShard(FindLocalShard message) { @@ -675,7 +837,7 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { // First see if the there is a local replica for the shard final ShardInformation info = localShards.get(shardName); - if (info != null) { + if (info != null && info.isActiveMember()) { sendResponse(info, message.isWaitUntilReady(), true, new Supplier() { @Override public Object get() { @@ -695,12 +857,25 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { return; } + Collection visitedAddresses; + if(message instanceof RemoteFindPrimary) { + visitedAddresses = ((RemoteFindPrimary)message).getVisitedAddresses(); + } else { + visitedAddresses = new ArrayList<>(); + } + + visitedAddresses.add(peerAddressResolver.getShardManagerActorPathBuilder(cluster.getSelfAddress()).toString()); + for(String address: peerAddressResolver.getShardManagerPeerActorAddresses()) { + if(visitedAddresses.contains(address)) { + continue; + } + LOG.debug("{}: findPrimary for {} forwarding to remote ShardManager {}", persistenceId(), shardName, address); getContext().actorSelection(address).forward(new RemoteFindPrimary(shardName, - message.isWaitUntilReady()), getContext()); + message.isWaitUntilReady(), visitedAddresses), getContext()); return; } @@ -731,20 +906,27 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { String memberName = this.cluster.getCurrentMemberName(); Collection memberShardNames = this.configuration.getMemberShardNames(memberName); - ShardPropsCreator shardPropsCreator = new DefaultShardPropsCreator(); - List localShardActorNames = new ArrayList<>(); + Map shardSnapshots = new HashMap<>(); + if(restoreFromSnapshot != null) + { + for(DatastoreSnapshot.ShardSnapshot snapshot: restoreFromSnapshot.getShardSnapshots()) { + shardSnapshots.put(snapshot.getName(), snapshot); + } + } + + restoreFromSnapshot = null; // null out to GC + for(String shardName : memberShardNames){ ShardIdentifier shardId = getShardIdentifier(memberName, shardName); + + LOG.debug("{}: Creating local shard: {}", persistenceId(), shardId); + Map peerAddresses = getPeerAddresses(shardName); - localShardActorNames.add(shardId.toString()); localShards.put(shardName, new ShardInformation(shardName, shardId, peerAddresses, - newShardDatastoreContext(shardName), shardPropsCreator, peerAddressResolver)); + newShardDatastoreContext(shardName), Shard.builder().restoreFromSnapshot( + shardSnapshots.get(shardName)), peerAddressResolver)); + mBean.addLocalShard(shardId.toString()); } - - mBean = ShardManagerInfo.createShardManagerMBean(memberName, "shard-manager-" + this.type, - datastoreContextFactory.getBaseDatastoreContext().getDataStoreMXBeanType(), localShardActorNames); - - mBean.setShardManager(this); } /** @@ -785,7 +967,7 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { @Override public String persistenceId() { - return "shard-manager-" + type; + return persistenceId; } @VisibleForTesting @@ -793,21 +975,21 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { return mBean; } - private void checkLocalShardExists(final String shardName, final ActorRef sender) { - if (localShards.containsKey(shardName)) { - String msg = String.format("Local shard %s already exists", shardName); + private boolean isShardReplicaOperationInProgress(final String shardName, final ActorRef sender) { + if (shardReplicaOperationsInProgress.contains(shardName)) { + String msg = String.format("A shard replica operation for %s is already in progress", shardName); LOG.debug ("{}: {}", persistenceId(), msg); - sender.tell(new akka.actor.Status.Failure(new IllegalArgumentException(msg)), getSelf()); + sender.tell(new akka.actor.Status.Failure(new IllegalStateException(msg)), getSelf()); + return true; } + + return false; } - private void onAddShardReplica (AddShardReplica shardReplicaMsg) { + private void onAddShardReplica (final AddShardReplica shardReplicaMsg) { final String shardName = shardReplicaMsg.getShardName(); - // verify the local shard replica is already available in the controller node - LOG.debug ("onAddShardReplica: {}", shardReplicaMsg); - - checkLocalShardExists(shardName, getSender()); + LOG.debug("{}: onAddShardReplica: {}", persistenceId(), shardReplicaMsg); // verify the shard with the specified name is present in the cluster configuration if (!(this.configuration.isShardConfigured(shardName))) { @@ -826,65 +1008,63 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { return; } - Map peerAddresses = getPeerAddresses(shardName); - if (peerAddresses.isEmpty()) { - String msg = String.format("Cannot add replica for shard %s because no peer is available", shardName); - LOG.debug ("{}: {}", persistenceId(), msg); - getSender().tell(new akka.actor.Status.Failure(new IllegalStateException(msg)), getSelf()); - return; - } - - Timeout findPrimaryTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext(). - getShardInitializationTimeout().duration().$times(2)); - - final ActorRef sender = getSender(); - Future futureObj = ask(getSelf(), new RemoteFindPrimary(shardName, true), findPrimaryTimeout); - futureObj.onComplete(new OnComplete() { + findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(), getSelf()) { @Override - public void onComplete(Throwable failure, Object response) { - if (failure != null) { - LOG.debug ("{}: Received failure from FindPrimary for shard {}", persistenceId(), shardName, failure); - sender.tell(new akka.actor.Status.Failure(new RuntimeException( - String.format("Failed to find leader for shard %s", shardName), failure)), - getSelf()); - } else { - if (!(response instanceof RemotePrimaryShardFound)) { - String msg = String.format("Failed to find leader for shard %s: received response: %s", - shardName, response); - LOG.debug ("{}: {}", persistenceId(), msg); - sender.tell(new akka.actor.Status.Failure(new RuntimeException(msg)), getSelf()); - return; - } + public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) { + getSelf().tell(new PrimaryShardFoundForContext(getShardName(), shardReplicaMsg, response), getTargetActor()); + } - RemotePrimaryShardFound message = (RemotePrimaryShardFound)response; - addShard (shardName, message, sender); - } + @Override + public void onLocalPrimaryFound(LocalPrimaryShardFound message) { + sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor()); } - }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client)); + + }); + } + + private void sendLocalReplicaAlreadyExistsReply(String shardName, ActorRef sender) { + String msg = String.format("Local shard %s already exists", shardName); + LOG.debug ("{}: {}", persistenceId(), msg); + sender.tell(new akka.actor.Status.Failure(new AlreadyExistsException(msg)), getSelf()); } private void addShard(final String shardName, final RemotePrimaryShardFound response, final ActorRef sender) { - checkLocalShardExists(shardName, sender); + if(isShardReplicaOperationInProgress(shardName, sender)) { + return; + } - ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName); - String localShardAddress = peerAddressResolver.getShardActorAddress(shardName, cluster.getCurrentMemberName()); + shardReplicaOperationsInProgress.add(shardName); + + final ShardInformation shardInfo; + final boolean removeShardOnFailure; + ShardInformation existingShardInfo = localShards.get(shardName); + if(existingShardInfo == null) { + removeShardOnFailure = true; + ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName); - DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).customRaftPolicyImplementation( - DisableElectionsRaftPolicy.class.getName()).build(); + DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).customRaftPolicyImplementation( + DisableElectionsRaftPolicy.class.getName()).build(); + + shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext, + Shard.builder(), peerAddressResolver); + shardInfo.setActiveMember(false); + localShards.put(shardName, shardInfo); + shardInfo.setActor(newShardActor(schemaContext, shardInfo)); + } else { + removeShardOnFailure = false; + shardInfo = existingShardInfo; + } - final ShardInformation shardInfo = new ShardInformation(shardName, shardId, - getPeerAddresses(shardName), datastoreContext, - new DefaultShardPropsCreator(), peerAddressResolver); - localShards.put(shardName, shardInfo); - shardInfo.setActor(newShardActor(schemaContext, shardInfo)); + String localShardAddress = peerAddressResolver.getShardActorAddress(shardName, cluster.getCurrentMemberName()); //inform ShardLeader to add this shard as a replica by sending an AddServer message LOG.debug ("{}: Sending AddServer message to peer {} for shard {}", persistenceId(), - response.getPrimaryPath(), shardId); + response.getPrimaryPath(), shardInfo.getShardId()); - Timeout addServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration().$times(4)); + Timeout addServerTimeout = new Timeout(shardInfo.getDatastoreContext().getShardLeaderElectionTimeout(). + duration()); Future futureObj = ask(getContext().actorSelection(response.getPrimaryPath()), - new AddServer(shardId.toString(), localShardAddress, true), addServerTimeout); + new AddServer(shardInfo.getShardId().toString(), localShardAddress, true), addServerTimeout); futureObj.onComplete(new OnComplete() { @Override @@ -893,27 +1073,37 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { LOG.debug ("{}: AddServer request to {} for {} failed", persistenceId(), response.getPrimaryPath(), shardName, failure); - // Remove the shard - localShards.remove(shardName); - if (shardInfo.getActor() != null) { - shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf()); - } - - sender.tell(new akka.actor.Status.Failure(new RuntimeException( - String.format("AddServer request to leader %s for shard %s failed", - response.getPrimaryPath(), shardName), failure)), getSelf()); + String msg = String.format("AddServer request to leader %s for shard %s failed", + response.getPrimaryPath(), shardName); + self().tell(new ForwardedAddServerFailure(shardName, msg, failure, removeShardOnFailure), sender); } else { - AddServerReply reply = (AddServerReply)addServerResponse; - onAddServerReply(shardName, shardInfo, reply, sender, response.getPrimaryPath()); + self().tell(new ForwardedAddServerReply(shardInfo, (AddServerReply)addServerResponse, + response.getPrimaryPath(), removeShardOnFailure), sender); } } - }, new Dispatchers(context().system().dispatchers()). - getDispatcher(Dispatchers.DispatcherType.Client)); - return; + }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client)); + } + + private void onAddServerFailure(String shardName, String message, Throwable failure, ActorRef sender, + boolean removeShardOnFailure) { + shardReplicaOperationsInProgress.remove(shardName); + + if(removeShardOnFailure) { + ShardInformation shardInfo = localShards.remove(shardName); + if (shardInfo.getActor() != null) { + shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf()); + } + } + + sender.tell(new akka.actor.Status.Failure(message == null ? failure : + new RuntimeException(message, failure)), getSelf()); } - private void onAddServerReply (String shardName, ShardInformation shardInfo, - AddServerReply replyMsg, ActorRef sender, String leaderPath) { + private void onAddServerReply(ShardInformation shardInfo, AddServerReply replyMsg, ActorRef sender, + String leaderPath, boolean removeShardOnFailure) { + String shardName = shardInfo.getShardName(); + shardReplicaOperationsInProgress.remove(shardName); + LOG.debug ("{}: Received {} for shard {} from leader {}", persistenceId(), replyMsg, shardName, leaderPath); if (replyMsg.getStatus() == ServerChangeStatus.OK) { @@ -921,49 +1111,139 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { // Make the local shard voting capable shardInfo.setDatastoreContext(newShardDatastoreContext(shardName), getSelf()); + shardInfo.setActiveMember(true); + persistShardList(); mBean.addLocalShard(shardInfo.getShardId().toString()); - sender.tell(new akka.actor.Status.Success(true), getSelf()); + sender.tell(new akka.actor.Status.Success(null), getSelf()); + } else if(replyMsg.getStatus() == ServerChangeStatus.ALREADY_EXISTS) { + sendLocalReplicaAlreadyExistsReply(shardName, sender); } else { - LOG.warn ("{}: Leader failed to add shard replica {} with status {} - removing the local shard", + LOG.warn ("{}: Leader failed to add shard replica {} with status {}", persistenceId(), shardName, replyMsg.getStatus()); - //remove the local replica created - localShards.remove(shardName); - if (shardInfo.getActor() != null) { - shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf()); + Exception failure = getServerChangeException(AddServer.class, replyMsg.getStatus(), leaderPath, shardInfo.getShardId()); + + onAddServerFailure(shardName, null, failure, sender, removeShardOnFailure); + } + } + + private Exception getServerChangeException(Class serverChange, ServerChangeStatus serverChangeStatus, + String leaderPath, ShardIdentifier shardId) { + Exception failure; + switch (serverChangeStatus) { + case TIMEOUT: + failure = new TimeoutException(String.format( + "The shard leader %s timed out trying to replicate the initial data to the new shard %s." + + "Possible causes - there was a problem replicating the data or shard leadership changed while replicating the shard data", + leaderPath, shardId.getShardName())); + break; + case NO_LEADER: + failure = createNoShardLeaderException(shardId); + break; + case NOT_SUPPORTED: + failure = new UnsupportedOperationException(String.format("%s request is not supported for shard %s", + serverChange.getSimpleName(), shardId.getShardName())); + break; + default : + failure = new RuntimeException(String.format( + "%s request to leader %s for shard %s failed with status %s", + serverChange.getSimpleName(), leaderPath, shardId.getShardName(), serverChangeStatus)); + } + return failure; + } + + private void onRemoveShardReplica (final RemoveShardReplica shardReplicaMsg) { + LOG.debug("{}: onRemoveShardReplica: {}", persistenceId(), shardReplicaMsg); + + findPrimary(shardReplicaMsg.getShardName(), new AutoFindPrimaryFailureResponseHandler(getSender(), + shardReplicaMsg.getShardName(), persistenceId(), getSelf()) { + @Override + public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) { + getSelf().tell(new PrimaryShardFoundForContext(getShardName(), shardReplicaMsg, response), getTargetActor()); } - switch (replyMsg.getStatus()) { - case TIMEOUT: - sender.tell(new akka.actor.Status.Failure(new RuntimeException( - String.format("The shard leader %s timed out trying to replicate the initial data to the new shard %s. Possible causes - there was a problem replicating the data or shard leadership changed while replicating the shard data", - leaderPath, shardName))), getSelf()); - break; - case NO_LEADER: - sender.tell(new akka.actor.Status.Failure(new RuntimeException(String.format( - "There is no shard leader available for shard %s", shardName))), getSelf()); - break; - default : - sender.tell(new akka.actor.Status.Failure(new RuntimeException(String.format( - "AddServer request to leader %s for shard %s failed with status %s", - leaderPath, shardName, replyMsg.getStatus()))), getSelf()); + + @Override + public void onLocalPrimaryFound(LocalPrimaryShardFound response) { + getSelf().tell(new PrimaryShardFoundForContext(getShardName(), shardReplicaMsg, response), getTargetActor()); + } + }); + } + + private void persistShardList() { + List shardList = new ArrayList<>(localShards.keySet()); + for (ShardInformation shardInfo : localShards.values()) { + if (!shardInfo.isActiveMember()) { + shardList.remove(shardInfo.getShardName()); } } + LOG.debug ("{}: persisting the shard list {}", persistenceId(), shardList); + saveSnapshot(updateShardManagerSnapshot(shardList)); } - private void onRemoveShardReplica (RemoveShardReplica shardReplicaMsg) { - String shardName = shardReplicaMsg.getShardName(); + private ShardManagerSnapshot updateShardManagerSnapshot(List shardList) { + currentSnapshot = new ShardManagerSnapshot(shardList); + return currentSnapshot; + } - // verify the local shard replica is available in the controller node - if (!localShards.containsKey(shardName)) { - String msg = String.format("Local shard %s does not", shardName); - LOG.debug ("{}: {}", persistenceId(), msg); - getSender().tell(new akka.actor.Status.Failure(new IllegalArgumentException(msg)), getSelf()); - return; + private void applyShardManagerSnapshot(ShardManagerSnapshot snapshot) { + currentSnapshot = snapshot; + + LOG.debug ("{}: onSnapshotOffer: {}", persistenceId(), currentSnapshot); + + String currentMember = cluster.getCurrentMemberName(); + Set configuredShardList = + new HashSet<>(configuration.getMemberShardNames(currentMember)); + for (String shard : currentSnapshot.getShardList()) { + if (!configuredShardList.contains(shard)) { + // add the current member as a replica for the shard + LOG.debug ("{}: adding shard {}", persistenceId(), shard); + configuration.addMemberReplicaForShard(shard, currentMember); + } else { + configuredShardList.remove(shard); + } + } + for (String shard : configuredShardList) { + // remove the member as a replica for the shard + LOG.debug ("{}: removing shard {}", persistenceId(), shard); + configuration.removeMemberReplicaForShard(shard, currentMember); + } + } + + private void onSaveSnapshotSuccess (SaveSnapshotSuccess successMessage) { + LOG.debug ("{} saved ShardManager snapshot successfully. Deleting the prev snapshot if available", + persistenceId()); + deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(), (successMessage.metadata().timestamp() - 1))); + } + + private static class ForwardedAddServerReply { + ShardInformation shardInfo; + AddServerReply addServerReply; + String leaderPath; + boolean removeShardOnFailure; + + ForwardedAddServerReply(ShardInformation shardInfo, AddServerReply addServerReply, String leaderPath, + boolean removeShardOnFailure) { + this.shardInfo = shardInfo; + this.addServerReply = addServerReply; + this.leaderPath = leaderPath; + this.removeShardOnFailure = removeShardOnFailure; + } + } + + private static class ForwardedAddServerFailure { + String shardName; + String failureMessage; + Throwable failure; + boolean removeShardOnFailure; + + ForwardedAddServerFailure(String shardName, String failureMessage, Throwable failure, + boolean removeShardOnFailure) { + this.shardName = shardName; + this.failureMessage = failureMessage; + this.failure = failure; + this.removeShardOnFailure = removeShardOnFailure; } - // call RemoveShard for the shardName - getSender().tell(new akka.actor.Status.Success(true), getSelf()); - return; } @VisibleForTesting @@ -987,28 +1267,34 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { private short leaderVersion; private DatastoreContext datastoreContext; - private final ShardPropsCreator shardPropsCreator; + private Shard.AbstractBuilder builder; private final ShardPeerAddressResolver addressResolver; + private boolean isActiveMember = true; private ShardInformation(String shardName, ShardIdentifier shardId, Map initialPeerAddresses, DatastoreContext datastoreContext, - ShardPropsCreator shardPropsCreator, ShardPeerAddressResolver addressResolver) { + Shard.AbstractBuilder builder, ShardPeerAddressResolver addressResolver) { this.shardName = shardName; this.shardId = shardId; this.initialPeerAddresses = initialPeerAddresses; this.datastoreContext = datastoreContext; - this.shardPropsCreator = shardPropsCreator; + this.builder = builder; this.addressResolver = addressResolver; } Props newProps(SchemaContext schemaContext) { - return shardPropsCreator.newProps(shardId, initialPeerAddresses, datastoreContext, schemaContext); + Preconditions.checkNotNull(builder); + Props props = builder.id(shardId).peerAddresses(initialPeerAddresses).datastoreContext(datastoreContext). + schemaContext(schemaContext).props(); + builder = null; + return props; } String getShardName() { return shardName; } + @Nullable ActorRef getActor(){ return actor; } @@ -1174,6 +1460,10 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { void setLeaderAvailable(boolean leaderAvailable) { this.leaderAvailable = leaderAvailable; + + if(leaderAvailable) { + notifyOnShardInitializedCallbacks(); + } } short getLeaderVersion() { @@ -1183,31 +1473,13 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { void setLeaderVersion(short leaderVersion) { this.leaderVersion = leaderVersion; } - } - - private static class ShardManagerCreator implements Creator { - private static final long serialVersionUID = 1L; - - final ClusterWrapper cluster; - final Configuration configuration; - final DatastoreContextFactory datastoreContextFactory; - private final CountDownLatch waitTillReadyCountdownLatch; - private final PrimaryShardInfoFutureCache primaryShardInfoCache; - ShardManagerCreator(ClusterWrapper cluster, Configuration configuration, - DatastoreContextFactory datastoreContextFactory, CountDownLatch waitTillReadyCountdownLatch, - PrimaryShardInfoFutureCache primaryShardInfoCache) { - this.cluster = cluster; - this.configuration = configuration; - this.datastoreContextFactory = datastoreContextFactory; - this.waitTillReadyCountdownLatch = waitTillReadyCountdownLatch; - this.primaryShardInfoCache = primaryShardInfoCache; + boolean isActiveMember() { + return isActiveMember; } - @Override - public ShardManager create() throws Exception { - return new ShardManager(cluster, configuration, datastoreContextFactory, waitTillReadyCountdownLatch, - primaryShardInfoCache); + void setActiveMember(boolean isActiveMember) { + this.isActiveMember = isActiveMember; } } @@ -1280,6 +1552,256 @@ public class ShardManager extends AbstractUntypedPersistentActorWithMetering { return modules; } } + + public static Builder builder() { + return new Builder(); + } + + public static abstract class AbstractBuilder> { + private ClusterWrapper cluster; + private Configuration configuration; + private DatastoreContextFactory datastoreContextFactory; + private CountDownLatch waitTillReadyCountdownLatch; + private PrimaryShardInfoFutureCache primaryShardInfoCache; + private DatastoreSnapshot restoreFromSnapshot; + + private volatile boolean sealed; + + @SuppressWarnings("unchecked") + private T self() { + return (T) this; + } + + protected void checkSealed() { + Preconditions.checkState(!sealed, "Builder is already sealed - further modifications are not allowed"); + } + + public T cluster(ClusterWrapper cluster) { + checkSealed(); + this.cluster = cluster; + return self(); + } + + public T configuration(Configuration configuration) { + checkSealed(); + this.configuration = configuration; + return self(); + } + + public T datastoreContextFactory(DatastoreContextFactory datastoreContextFactory) { + checkSealed(); + this.datastoreContextFactory = datastoreContextFactory; + return self(); + } + + public T waitTillReadyCountdownLatch(CountDownLatch waitTillReadyCountdownLatch) { + checkSealed(); + this.waitTillReadyCountdownLatch = waitTillReadyCountdownLatch; + return self(); + } + + public T primaryShardInfoCache(PrimaryShardInfoFutureCache primaryShardInfoCache) { + checkSealed(); + this.primaryShardInfoCache = primaryShardInfoCache; + return self(); + } + + public T restoreFromSnapshot(DatastoreSnapshot restoreFromSnapshot) { + checkSealed(); + this.restoreFromSnapshot = restoreFromSnapshot; + return self(); + } + + protected void verify() { + sealed = true; + Preconditions.checkNotNull(cluster, "cluster should not be null"); + Preconditions.checkNotNull(configuration, "configuration should not be null"); + Preconditions.checkNotNull(datastoreContextFactory, "datastoreContextFactory should not be null"); + Preconditions.checkNotNull(waitTillReadyCountdownLatch, "waitTillReadyCountdownLatch should not be null"); + Preconditions.checkNotNull(primaryShardInfoCache, "primaryShardInfoCache should not be null"); + } + + public Props props() { + verify(); + return Props.create(ShardManager.class, this); + } + } + + public static class Builder extends AbstractBuilder { + } + + private void findPrimary(final String shardName, final FindPrimaryResponseHandler handler) { + Timeout findPrimaryTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext(). + getShardInitializationTimeout().duration().$times(2)); + + + Future futureObj = ask(getSelf(), new FindPrimary(shardName, true), findPrimaryTimeout); + futureObj.onComplete(new OnComplete() { + @Override + public void onComplete(Throwable failure, Object response) { + if (failure != null) { + handler.onFailure(failure); + } else { + if(response instanceof RemotePrimaryShardFound) { + handler.onRemotePrimaryShardFound((RemotePrimaryShardFound) response); + } else if(response instanceof LocalPrimaryShardFound) { + handler.onLocalPrimaryFound((LocalPrimaryShardFound) response); + } else { + handler.onUnknownResponse(response); + } + } + } + }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client)); + } + + /** + * The FindPrimaryResponseHandler provides specific callback methods which are invoked when a response to the + * a remote or local find primary message is processed + */ + private static interface FindPrimaryResponseHandler { + /** + * Invoked when a Failure message is received as a response + * + * @param failure + */ + void onFailure(Throwable failure); + + /** + * Invoked when a RemotePrimaryShardFound response is received + * + * @param response + */ + void onRemotePrimaryShardFound(RemotePrimaryShardFound response); + + /** + * Invoked when a LocalPrimaryShardFound response is received + * @param response + */ + void onLocalPrimaryFound(LocalPrimaryShardFound response); + + /** + * Invoked when an unknown response is received. This is another type of failure. + * + * @param response + */ + void onUnknownResponse(Object response); + } + + /** + * The AutoFindPrimaryFailureResponseHandler automatically processes Failure responses when finding a primary + * replica and sends a wrapped Failure response to some targetActor + */ + private static abstract class AutoFindPrimaryFailureResponseHandler implements FindPrimaryResponseHandler { + private final ActorRef targetActor; + private final String shardName; + private final String persistenceId; + private final ActorRef shardManagerActor; + + /** + * @param targetActor The actor to whom the Failure response should be sent when a FindPrimary failure occurs + * @param shardName The name of the shard for which the primary replica had to be found + * @param persistenceId The persistenceId for the ShardManager + * @param shardManagerActor The ShardManager actor which triggered the call to FindPrimary + */ + protected AutoFindPrimaryFailureResponseHandler(ActorRef targetActor, String shardName, String persistenceId, ActorRef shardManagerActor){ + this.targetActor = Preconditions.checkNotNull(targetActor); + this.shardName = Preconditions.checkNotNull(shardName); + this.persistenceId = Preconditions.checkNotNull(persistenceId); + this.shardManagerActor = Preconditions.checkNotNull(shardManagerActor); + } + + public ActorRef getTargetActor() { + return targetActor; + } + + public String getShardName() { + return shardName; + } + + @Override + public void onFailure(Throwable failure) { + LOG.debug ("{}: Received failure from FindPrimary for shard {}", persistenceId, shardName, failure); + targetActor.tell(new akka.actor.Status.Failure(new RuntimeException( + String.format("Failed to find leader for shard %s", shardName), failure)), shardManagerActor); + } + + @Override + public void onUnknownResponse(Object response) { + String msg = String.format("Failed to find leader for shard %s: received response: %s", + shardName, response); + LOG.debug ("{}: {}", persistenceId, msg); + targetActor.tell(new akka.actor.Status.Failure(response instanceof Throwable ? (Throwable) response : + new RuntimeException(msg)), shardManagerActor); + } + } + + + /** + * The PrimaryShardFoundForContext is a DTO which puts together a message (aka 'Context' message) which needs to be + * forwarded to the primary replica of a shard and the message (aka 'PrimaryShardFound' message) that is received + * as a successful response to find primary. + */ + private static class PrimaryShardFoundForContext { + private final String shardName; + private final Object contextMessage; + private final RemotePrimaryShardFound remotePrimaryShardFound; + private final LocalPrimaryShardFound localPrimaryShardFound; + + public PrimaryShardFoundForContext(@Nonnull String shardName, @Nonnull Object contextMessage, + @Nonnull Object primaryFoundMessage) { + this.shardName = Preconditions.checkNotNull(shardName); + this.contextMessage = Preconditions.checkNotNull(contextMessage); + Preconditions.checkNotNull(primaryFoundMessage); + this.remotePrimaryShardFound = (primaryFoundMessage instanceof RemotePrimaryShardFound) ? + (RemotePrimaryShardFound) primaryFoundMessage : null; + this.localPrimaryShardFound = (primaryFoundMessage instanceof LocalPrimaryShardFound) ? + (LocalPrimaryShardFound) primaryFoundMessage : null; + } + + @Nonnull + String getPrimaryPath(){ + if(remotePrimaryShardFound != null) { + return remotePrimaryShardFound.getPrimaryPath(); + } + return localPrimaryShardFound.getPrimaryPath(); + } + + @Nonnull + Object getContextMessage() { + return contextMessage; + } + + @Nullable + RemotePrimaryShardFound getRemotePrimaryShardFound() { + return remotePrimaryShardFound; + } + + @Nonnull + String getShardName() { + return shardName; + } + } + + /** + * The WrappedShardResponse class wraps a response from a Shard. + */ + private static class WrappedShardResponse { + private final String shardName; + private final Object response; + + private WrappedShardResponse(String shardName, Object response) { + this.shardName = shardName; + this.response = response; + } + + String getShardName() { + return shardName; + } + + Object getResponse() { + return response; + } + } }