Make sure we purge transaction on abort
[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / main / java / org / opendaylight / controller / cluster / datastore / Shard.java
index d9483d7b2b61915295eef094fc8c8570f0b63eaa..897527764c18b2ae26061b014ac22e5e24ab4de5 100644 (file)
@@ -5,15 +5,16 @@
  * 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;
 
 import akka.actor.ActorRef;
 import akka.actor.ActorSelection;
 import akka.actor.Cancellable;
+import akka.actor.ExtendedActorSystem;
 import akka.actor.Props;
 import akka.actor.Status;
 import akka.actor.Status.Failure;
+import akka.serialization.JavaSerializer;
 import akka.serialization.Serialization;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Optional;
@@ -29,13 +30,14 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
-import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
+import org.eclipse.jdt.annotation.NonNull;
+import org.eclipse.jdt.annotation.Nullable;
 import org.opendaylight.controller.cluster.access.ABIVersion;
 import org.opendaylight.controller.cluster.access.commands.ConnectClientRequest;
 import org.opendaylight.controller.cluster.access.commands.ConnectClientSuccess;
 import org.opendaylight.controller.cluster.access.commands.LocalHistoryRequest;
 import org.opendaylight.controller.cluster.access.commands.NotLeaderException;
+import org.opendaylight.controller.cluster.access.commands.OutOfSequenceEnvelopeException;
 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
 import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
 import org.opendaylight.controller.cluster.access.concepts.FrontendIdentifier;
@@ -57,6 +59,7 @@ import org.opendaylight.controller.cluster.common.actor.MessageTracker.Error;
 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
+import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardDataTreeListenerInfoMXBeanImpl;
 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardMBeanFactory;
 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
@@ -74,13 +77,13 @@ import org.opendaylight.controller.cluster.datastore.messages.OnDemandShardState
 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
 import org.opendaylight.controller.cluster.datastore.messages.PersistAbortTransactionPayload;
 import org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction;
-import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
 import org.opendaylight.controller.cluster.datastore.persisted.AbortTransactionPayload;
 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot;
 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot.ShardSnapshot;
+import org.opendaylight.controller.cluster.messaging.MessageAssembler;
 import org.opendaylight.controller.cluster.messaging.MessageSlicer;
 import org.opendaylight.controller.cluster.messaging.SliceOptions;
 import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
@@ -98,12 +101,11 @@ import org.opendaylight.controller.cluster.raft.messages.RequestLeadership;
 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
 import org.opendaylight.yangtools.concepts.Identifier;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
-import org.opendaylight.yangtools.yang.data.api.schema.tree.TipProducingDataTree;
 import org.opendaylight.yangtools.yang.data.api.schema.tree.TreeType;
 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 import org.opendaylight.yangtools.yang.model.api.SchemaContextProvider;
-import scala.concurrent.duration.Duration;
 import scala.concurrent.duration.FiniteDuration;
 
 /**
@@ -157,8 +159,12 @@ public class Shard extends RaftActor {
     /// The name of this shard
     private final String name;
 
+    private final String shardName;
+
     private final ShardStats shardMBean;
 
+    private final ShardDataTreeListenerInfoMXBeanImpl listenerInfoMXBean;
+
     private DatastoreContext datastoreContext;
 
     private final ShardCommitCoordinator commitCoordinator;
@@ -176,8 +182,6 @@ public class Shard extends RaftActor {
     private final ShardSnapshotCohort snapshotCohort;
 
     private final DataTreeChangeListenerSupport treeChangeSupport = new DataTreeChangeListenerSupport(this);
-    private final DataChangeListenerSupport changeSupport = new DataChangeListenerSupport(this);
-
 
     private ShardSnapshot restoreFromSnapshot;
 
@@ -190,11 +194,14 @@ public class Shard extends RaftActor {
     private final MessageSlicer responseMessageSlicer;
     private final Dispatchers dispatchers;
 
+    private final MessageAssembler requestMessageAssembler;
+
     protected Shard(final AbstractBuilder<?, ?> builder) {
         super(builder.getId().toString(), builder.getPeerAddresses(),
                 Optional.of(builder.getDatastoreContext().getShardRaftConfig()), DataStoreVersions.CURRENT_VERSION);
 
         this.name = builder.getId().toString();
+        this.shardName = builder.getId().getShardName();
         this.datastoreContext = builder.getDatastoreContext();
         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
         this.frontendMetadata = new FrontendMetadata(name);
@@ -205,15 +212,12 @@ public class Shard extends RaftActor {
 
         ShardDataTreeChangeListenerPublisherActorProxy treeChangeListenerPublisher =
                 new ShardDataTreeChangeListenerPublisherActorProxy(getContext(), name + "-DTCL-publisher", name);
-        ShardDataChangeListenerPublisherActorProxy dataChangeListenerPublisher =
-                new ShardDataChangeListenerPublisherActorProxy(getContext(), name + "-DCL-publisher", name);
         if (builder.getDataTree() != null) {
             store = new ShardDataTree(this, builder.getSchemaContext(), builder.getDataTree(),
-                    treeChangeListenerPublisher, dataChangeListenerPublisher, name, frontendMetadata);
+                    treeChangeListenerPublisher, name, frontendMetadata);
         } else {
             store = new ShardDataTree(this, builder.getSchemaContext(), builder.getTreeType(),
-                    builder.getDatastoreContext().getStoreRoot(), treeChangeListenerPublisher,
-                    dataChangeListenerPublisher, name, frontendMetadata);
+                    builder.getDatastoreContext().getStoreRoot(), treeChangeListenerPublisher, name, frontendMetadata);
         }
 
         shardMBean = ShardMBeanFactory.getShardStatsMBean(name, datastoreContext.getDataStoreMXBeanType(), this);
@@ -246,6 +250,15 @@ public class Shard extends RaftActor {
                 .messageSliceSize(datastoreContext.getMaximumMessageSliceSize())
                 .fileBackedStreamFactory(getRaftActorContext().getFileBackedOutputStreamFactory())
                 .expireStateAfterInactivity(2, TimeUnit.MINUTES).build();
+
+        requestMessageAssembler = MessageAssembler.builder().logContext(this.name)
+                .fileBackedStreamFactory(getRaftActorContext().getFileBackedOutputStreamFactory())
+                .assembledMessageCallback((message, sender) -> self().tell(message, sender))
+                .expireStateAfterInactivity(datastoreContext.getRequestTimeout(), TimeUnit.NANOSECONDS).build();
+
+        listenerInfoMXBean = new ShardDataTreeListenerInfoMXBeanImpl(name, datastoreContext.getDataStoreMXBeanType(),
+                self());
+        listenerInfoMXBean.register();
     }
 
     private void setTransactionCommitTimeout() {
@@ -274,6 +287,7 @@ public class Shard extends RaftActor {
         commitCoordinator.abortPendingTransactions("Transaction aborted due to shutdown.", this);
 
         shardMBean.unregisterMBean();
+        listenerInfoMXBean.unregister();
     }
 
     @Override
@@ -300,6 +314,8 @@ public class Shard extends RaftActor {
 
             if (message instanceof RequestEnvelope) {
                 handleRequestEnvelope((RequestEnvelope)message);
+            } else if (MessageAssembler.isHandledMessage(message)) {
+                handleRequestAssemblerMessage(message);
             } else if (message instanceof ConnectClientRequest) {
                 handleConnectClient((ConnectClientRequest)message);
             } else if (CreateTransaction.isSerializedType(message)) {
@@ -318,8 +334,6 @@ public class Shard extends RaftActor {
                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
             } else if (CloseTransactionChain.isSerializedType(message)) {
                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
-            } else if (message instanceof RegisterChangeListener) {
-                changeSupport.onMessage((RegisterChangeListener) message, isLeader(), hasLeader());
             } else if (message instanceof RegisterDataTreeChangeListener) {
                 treeChangeSupport.onMessage((RegisterDataTreeChangeListener) message, isLeader(), hasLeader());
             } else if (message instanceof UpdateSchemaContext) {
@@ -328,8 +342,7 @@ public class Shard extends RaftActor {
                 PeerAddressResolved resolved = (PeerAddressResolved) message;
                 setPeerAddress(resolved.getPeerId(), resolved.getPeerAddress());
             } else if (TX_COMMIT_TIMEOUT_CHECK_MESSAGE.equals(message)) {
-                store.checkForExpiredTransactions(transactionCommitTimeout);
-                commitCoordinator.checkForExpiredTransactions(transactionCommitTimeout, this);
+                commitTimeoutCheck();
             } else if (message instanceof DatastoreContext) {
                 onDatastoreContext((DatastoreContext)message);
             } else if (message instanceof RegisterRoleChangeListener) {
@@ -350,7 +363,9 @@ public class Shard extends RaftActor {
                         (DataTreeCohortActorRegistry.CohortRegistryCommand) message);
             } else if (message instanceof PersistAbortTransactionPayload) {
                 final TransactionIdentifier txId = ((PersistAbortTransactionPayload) message).getTransactionId();
-                persistPayload(txId, AbortTransactionPayload.create(txId), true);
+                persistPayload(txId, AbortTransactionPayload.create(
+                        txId, datastoreContext.getInitialPayloadSerializedBufferCapacity()), true);
+                store.purgeTransaction(txId, null);
             } else if (message instanceof MakeLeaderLocal) {
                 onMakeLeaderLocal();
             } else if (RESUME_NEXT_PENDING_TRANSACTION.equals(message)) {
@@ -361,6 +376,13 @@ public class Shard extends RaftActor {
         }
     }
 
+    private void handleRequestAssemblerMessage(final Object message) {
+        dispatchers.getDispatcher(DispatcherType.Serialization).execute(() -> {
+            JavaSerializer.currentSystem().value_$eq((ExtendedActorSystem) context().system());
+            requestMessageAssembler.handleMessage(message, self());
+        });
+    }
+
     @SuppressWarnings("checkstyle:IllegalCatch")
     private void handleRequestEnvelope(final RequestEnvelope envelope) {
         final long now = ticker().read();
@@ -373,9 +395,7 @@ public class Shard extends RaftActor {
                         responseMessageSlicer.slice(SliceOptions.builder().identifier(success.getTarget())
                             .message(envelope.newSuccessEnvelope(success, executionTimeNanos))
                             .sendTo(envelope.getMessage().getReplyTo()).replyTo(self())
-                            .onFailureCallback(t -> {
-                                LOG.warn("Error slicing response {}", success, t);
-                            }).build()));
+                            .onFailureCallback(t -> LOG.warn("Error slicing response {}", success, t)).build()));
                 } else {
                     envelope.sendSuccess(success, executionTimeNanos);
                 }
@@ -390,6 +410,30 @@ public class Shard extends RaftActor {
         }
     }
 
+    private void commitTimeoutCheck() {
+        store.checkForExpiredTransactions(transactionCommitTimeout, this::updateAccess);
+        commitCoordinator.checkForExpiredTransactions(transactionCommitTimeout, this);
+        requestMessageAssembler.checkExpiredAssembledMessageState();
+    }
+
+    private Optional<Long> updateAccess(final SimpleShardDataTreeCohort cohort) {
+        final FrontendIdentifier frontend = cohort.getIdentifier().getHistoryId().getClientId().getFrontendId();
+        final LeaderFrontendState state = knownFrontends.get(frontend);
+        if (state == null) {
+            // Not tell-based protocol, do nothing
+            return Optional.absent();
+        }
+
+        if (isIsolatedLeader()) {
+            // We are isolated and no new request can come through until we emerge from it. We are still updating
+            // liveness of frontend when we see it attempting to communicate. Use the last access timer.
+            return Optional.of(state.getLastSeenTicks());
+        }
+
+        // If this frontend has freshly connected, give it some time to catch up before killing its transactions.
+        return Optional.of(state.getLastConnectTicks());
+    }
+
     private void onMakeLeaderLocal() {
         LOG.debug("{}: onMakeLeaderLocal received", persistenceId());
         if (isLeader()) {
@@ -417,16 +461,18 @@ public class Shard extends RaftActor {
     }
 
     // Acquire our frontend tracking handle and verify generation matches
-    private LeaderFrontendState getFrontend(final ClientIdentifier clientId) throws RequestException {
+    private @Nullable LeaderFrontendState findFrontend(final ClientIdentifier clientId) throws RequestException {
         final LeaderFrontendState existing = knownFrontends.get(clientId.getFrontendId());
         if (existing != null) {
             final int cmp = Long.compareUnsigned(existing.getIdentifier().getGeneration(), clientId.getGeneration());
             if (cmp == 0) {
+                existing.touch();
                 return existing;
             }
             if (cmp > 0) {
                 LOG.debug("{}: rejecting request from outdated client {}", persistenceId(), clientId);
-                throw new RetiredGenerationException(existing.getIdentifier().getGeneration());
+                throw new RetiredGenerationException(clientId.getGeneration(),
+                    existing.getIdentifier().getGeneration());
             }
 
             LOG.info("{}: retiring state {}, outdated by request from client {}", persistenceId(), existing, clientId);
@@ -436,13 +482,20 @@ public class Shard extends RaftActor {
             LOG.debug("{}: client {} is not yet known", persistenceId(), clientId);
         }
 
-        final LeaderFrontendState ret = new LeaderFrontendState(persistenceId(), clientId, store);
-        knownFrontends.put(clientId.getFrontendId(), ret);
-        LOG.debug("{}: created state {} for client {}", persistenceId(), ret, clientId);
-        return ret;
+        return null;
     }
 
-    private static @Nonnull ABIVersion selectVersion(final ConnectClientRequest message) {
+    private LeaderFrontendState getFrontend(final ClientIdentifier clientId) throws RequestException {
+        final LeaderFrontendState ret = findFrontend(clientId);
+        if (ret != null) {
+            return ret;
+        }
+
+        // TODO: a dedicated exception would be better, but this is technically true, too
+        throw new OutOfSequenceEnvelopeException(0);
+    }
+
+    private static @NonNull ABIVersion selectVersion(final ConnectClientRequest message) {
         final Range<ABIVersion> clientRange = Range.closed(message.getMinVersion(), message.getMaxVersion());
         for (ABIVersion v : SUPPORTED_ABIVERSIONS) {
             if (clientRange.contains(v)) {
@@ -458,6 +511,12 @@ public class Shard extends RaftActor {
     @SuppressWarnings("checkstyle:IllegalCatch")
     private void handleConnectClient(final ConnectClientRequest message) {
         try {
+            final ClientIdentifier clientId = message.getTarget();
+            final LeaderFrontendState existing = findFrontend(clientId);
+            if (existing != null) {
+                existing.touch();
+            }
+
             if (!isLeader() || !isLeaderActive()) {
                 LOG.info("{}: not currently leader, rejecting request {}. isLeader: {}, isLeaderActive: {},"
                                 + "isLeadershipTransferInProgress: {}.",
@@ -466,7 +525,15 @@ public class Shard extends RaftActor {
             }
 
             final ABIVersion selectedVersion = selectVersion(message);
-            final LeaderFrontendState frontend = getFrontend(message.getTarget());
+            final LeaderFrontendState frontend;
+            if (existing == null) {
+                frontend = new LeaderFrontendState(persistenceId(), clientId, store);
+                knownFrontends.put(clientId.getFrontendId(), frontend);
+                LOG.debug("{}: created state {} for client {}", persistenceId(), frontend, clientId);
+            } else {
+                frontend = existing;
+            }
+
             frontend.reconnect();
             message.getReplyTo().tell(new ConnectClientSuccess(message.getTarget(), message.getSequence(), getSelf(),
                 ImmutableList.of(), store.getDataTree(), CLIENT_MAX_MESSAGES).toVersion(selectedVersion),
@@ -518,6 +585,10 @@ public class Shard extends RaftActor {
         return roleChangeNotifier;
     }
 
+    String getShardName() {
+        return shardName;
+    }
+
     @Override
     protected LeaderStateChanged newLeaderStateChanged(final String memberId, final String leaderId,
             final short leaderPayloadVersion) {
@@ -609,7 +680,7 @@ public class Shard extends RaftActor {
             ActorSelection leader = getLeader();
             if (!isLeaderActive || leader == null) {
                 messageRetrySupport.addMessageToRetry(batched, getSender(),
-                        "Could not commit transaction " + batched.getTransactionId());
+                        "Could not process BatchedModifications " + batched.getTransactionId());
             } else {
                 // If this is not the first batch and leadership changed in between batched messages,
                 // we need to reconstruct previous BatchedModifications from the transaction
@@ -662,7 +733,7 @@ public class Shard extends RaftActor {
             ActorSelection leader = getLeader();
             if (!isLeaderActive || leader == null) {
                 messageRetrySupport.addMessageToRetry(message, getSender(),
-                        "Could not commit transaction " + message.getTransactionId());
+                        "Could not process ready local transaction " + message.getTransactionId());
             } else {
                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
@@ -681,12 +752,13 @@ public class Shard extends RaftActor {
             ActorSelection leader = getLeader();
             if (!isLeaderActive || leader == null) {
                 messageRetrySupport.addMessageToRetry(forwardedReady, getSender(),
-                        "Could not commit transaction " + forwardedReady.getTransactionId());
+                        "Could not process forwarded ready transaction " + forwardedReady.getTransactionId());
             } else {
                 LOG.debug("{}: Forwarding ForwardedReadyTransaction to leader {}", persistenceId(), leader);
 
                 ReadyLocalTransaction readyLocal = new ReadyLocalTransaction(forwardedReady.getTransactionId(),
-                        forwardedReady.getTransaction().getSnapshot(), forwardedReady.isDoImmediateCommit());
+                        forwardedReady.getTransaction().getSnapshot(), forwardedReady.isDoImmediateCommit(),
+                        forwardedReady.getParticipatingShardNames());
                 readyLocal.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
                 leader.forward(readyLocal, getContext());
             }
@@ -713,9 +785,16 @@ public class Shard extends RaftActor {
     }
 
     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
-        final LocalHistoryIdentifier id = closeTransactionChain.getIdentifier();
-        store.closeTransactionChain(id, null);
-        store.purgeTransactionChain(id, null);
+        if (isLeader()) {
+            final LocalHistoryIdentifier id = closeTransactionChain.getIdentifier();
+            // FIXME: CONTROLLER-1628: stage purge once no transactions are present
+            store.closeTransactionChain(id, null);
+            store.purgeTransactionChain(id, null);
+        } else if (getLeader() != null) {
+            getLeader().forward(closeTransactionChain, getContext());
+        } else {
+            LOG.warn("{}: Could not close transaction {}", persistenceId(), closeTransactionChain.getIdentifier());
+        }
     }
 
     @SuppressWarnings("checkstyle:IllegalCatch")
@@ -763,10 +842,12 @@ public class Shard extends RaftActor {
     }
 
     @Override
-    @Nonnull
     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
-        return new ShardRecoveryCoordinator(store,
-            restoreFromSnapshot != null ? restoreFromSnapshot.getSnapshot() : null, persistenceId(), LOG);
+        if (restoreFromSnapshot == null) {
+            return ShardRecoveryCoordinator.create(store, persistenceId(), LOG);
+        }
+
+        return ShardRecoveryCoordinator.forSnapshot(store, persistenceId(), LOG, restoreFromSnapshot.getSnapshot());
     }
 
     @Override
@@ -780,7 +861,7 @@ public class Shard extends RaftActor {
         if (txCommitTimeoutCheckSchedule == null) {
             // Schedule a message to be periodically sent to check if the current in-progress
             // transaction should be expired and aborted.
-            FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
+            FiniteDuration period = FiniteDuration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
                     period, period, getSelf(),
                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
@@ -804,7 +885,6 @@ public class Shard extends RaftActor {
     protected void onStateChanged() {
         boolean isLeader = isLeader();
         boolean hasLeader = hasLeader();
-        changeSupport.onLeadershipChange(isLeader, hasLeader);
         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 
         // If this actor is no longer the leader close all the transaction chains
@@ -835,6 +915,8 @@ public class Shard extends RaftActor {
                 knownFrontends = ImmutableMap.of();
             }
 
+            requestMessageAssembler.close();
+
             if (!hasLeader()) {
                 // No leader anywhere, nothing else to do
                 return;
@@ -851,6 +933,8 @@ public class Shard extends RaftActor {
                             messagesToForward.size(), leader);
 
                     for (Object message : messagesToForward) {
+                        LOG.debug("{}: Forwarding pending transaction message {}", persistenceId(), message);
+
                         leader.tell(message, self());
                     }
                 }
@@ -903,9 +987,8 @@ public class Shard extends RaftActor {
     }
 
     @Override
-    protected OnDemandRaftState.AbstractBuilder<?> newOnDemandRaftStateBuilder() {
+    protected OnDemandRaftState.AbstractBuilder<?, ?> newOnDemandRaftStateBuilder() {
         return OnDemandShardState.newBuilder().treeChangeListenerActors(treeChangeSupport.getListenerActors())
-                .dataChangeListenerActors(changeSupport.getListenerActors())
                 .commitCohortActors(store.getCohortActors());
     }
 
@@ -944,7 +1027,7 @@ public class Shard extends RaftActor {
         private DatastoreContext datastoreContext;
         private SchemaContextProvider schemaContextProvider;
         private DatastoreSnapshot.ShardSnapshot restoreFromSnapshot;
-        private TipProducingDataTree dataTree;
+        private DataTree dataTree;
         private volatile boolean sealed;
 
         protected AbstractBuilder(final Class<S> shardClass) {
@@ -978,9 +1061,9 @@ public class Shard extends RaftActor {
             return self();
         }
 
-        public T schemaContextProvider(final SchemaContextProvider schemaContextProvider) {
+        public T schemaContextProvider(final SchemaContextProvider newSchemaContextProvider) {
             checkSealed();
-            this.schemaContextProvider = Preconditions.checkNotNull(schemaContextProvider);
+            this.schemaContextProvider = Preconditions.checkNotNull(newSchemaContextProvider);
             return self();
         }
 
@@ -990,7 +1073,7 @@ public class Shard extends RaftActor {
             return self();
         }
 
-        public T dataTree(final TipProducingDataTree newDataTree) {
+        public T dataTree(final DataTree newDataTree) {
             checkSealed();
             this.dataTree = newDataTree;
             return self();
@@ -1016,7 +1099,7 @@ public class Shard extends RaftActor {
             return restoreFromSnapshot;
         }
 
-        public TipProducingDataTree getDataTree() {
+        public DataTree getDataTree() {
             return dataTree;
         }
 
@@ -1047,7 +1130,7 @@ public class Shard extends RaftActor {
     }
 
     public static class Builder extends AbstractBuilder<Builder, Shard> {
-        private Builder() {
+        Builder() {
             super(Shard.class);
         }
     }