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%2FShardDataTree.java;h=5a59b0d16328082d1d2c4cf98186544c1efa849d;hp=be2e6d47fbc776ee58efef233b3a4c73c8e50865;hb=d19cf96d390ffcdba8b1f64a6dd3f3749ecc5872;hpb=43aab07cdbc80eda69e84a26085afe1b37f4002e diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardDataTree.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardDataTree.java index be2e6d47fb..5a59b0d163 100644 --- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardDataTree.java +++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ShardDataTree.java @@ -7,68 +7,204 @@ */ package org.opendaylight.controller.cluster.datastore; -import com.google.common.base.Optional; -import com.google.common.base.Preconditions; -import com.google.common.base.Strings; -import java.util.AbstractMap.SimpleEntry; +import static com.google.common.base.Preconditions.checkState; +import static com.google.common.base.Verify.verify; +import static com.google.common.base.Verify.verifyNotNull; +import static java.util.Objects.requireNonNull; + +import akka.actor.ActorRef; +import akka.util.Timeout; +import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.MoreObjects; +import com.google.common.base.Stopwatch; +import com.google.common.collect.ImmutableList; +import com.google.common.collect.ImmutableMap; +import com.google.common.collect.ImmutableMap.Builder; +import com.google.common.collect.Iterables; +import com.google.common.primitives.UnsignedLong; +import com.google.common.util.concurrent.FutureCallback; +import edu.umd.cs.findbugs.annotations.SuppressFBWarnings; +import java.io.File; +import java.io.IOException; +import java.util.ArrayDeque; +import java.util.ArrayList; +import java.util.Collection; +import java.util.Collections; +import java.util.Deque; import java.util.HashMap; +import java.util.Iterator; import java.util.Map; import java.util.Map.Entry; -import javax.annotation.concurrent.NotThreadSafe; -import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker.DataChangeScope; -import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener; -import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener; -import org.opendaylight.controller.md.sal.dom.store.impl.DataChangeListenerRegistration; -import org.opendaylight.controller.md.sal.dom.store.impl.ResolveDataChangeEventsTask; -import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerTree; +import java.util.Optional; +import java.util.OptionalLong; +import java.util.Queue; +import java.util.SortedSet; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.TimeoutException; +import java.util.function.Consumer; +import java.util.function.Function; +import java.util.function.UnaryOperator; +import org.eclipse.jdt.annotation.NonNull; +import org.eclipse.jdt.annotation.Nullable; +import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier; +import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier; +import org.opendaylight.controller.cluster.datastore.DataTreeCohortActorRegistry.CohortRegistryCommand; +import org.opendaylight.controller.cluster.datastore.ShardDataTreeCohort.State; +import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats; +import org.opendaylight.controller.cluster.datastore.node.utils.transformer.ReusableNormalizedNodePruner; +import org.opendaylight.controller.cluster.datastore.persisted.AbortTransactionPayload; +import org.opendaylight.controller.cluster.datastore.persisted.AbstractIdentifiablePayload; +import org.opendaylight.controller.cluster.datastore.persisted.CloseLocalHistoryPayload; +import org.opendaylight.controller.cluster.datastore.persisted.CommitTransactionPayload; +import org.opendaylight.controller.cluster.datastore.persisted.CreateLocalHistoryPayload; +import org.opendaylight.controller.cluster.datastore.persisted.DataTreeCandidateInputOutput.DataTreeCandidateWithVersion; +import org.opendaylight.controller.cluster.datastore.persisted.MetadataShardDataTreeSnapshot; +import org.opendaylight.controller.cluster.datastore.persisted.PayloadVersion; +import org.opendaylight.controller.cluster.datastore.persisted.PurgeLocalHistoryPayload; +import org.opendaylight.controller.cluster.datastore.persisted.PurgeTransactionPayload; +import org.opendaylight.controller.cluster.datastore.persisted.ShardDataTreeSnapshot; +import org.opendaylight.controller.cluster.datastore.persisted.ShardDataTreeSnapshotMetadata; +import org.opendaylight.controller.cluster.datastore.persisted.ShardSnapshotState; +import org.opendaylight.controller.cluster.datastore.utils.DataTreeModificationOutput; +import org.opendaylight.controller.cluster.datastore.utils.PruningDataTreeModification; +import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload; +import org.opendaylight.mdsal.common.api.OptimisticLockFailedException; +import org.opendaylight.mdsal.common.api.TransactionCommitFailedException; +import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener; +import org.opendaylight.yangtools.concepts.Identifier; import org.opendaylight.yangtools.concepts.ListenerRegistration; import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier; import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode; +import org.opendaylight.yangtools.yang.data.api.schema.tree.ConflictingModificationAppliedException; +import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree; import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate; import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateTip; import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidates; +import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeConfiguration; import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification; import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot; +import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeTip; 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.data.codec.binfmt.NormalizedNodeStreamVersion; import org.opendaylight.yangtools.yang.data.impl.schema.tree.InMemoryDataTreeFactory; +import org.opendaylight.yangtools.yang.data.util.DataSchemaContextTree; import org.opendaylight.yangtools.yang.model.api.SchemaContext; import org.slf4j.Logger; import org.slf4j.LoggerFactory; +import scala.concurrent.duration.FiniteDuration; /** - * Internal shard state, similar to a DOMStore, but optimized for use in the actor system, - * e.g. it does not expose public interfaces and assumes it is only ever called from a - * single thread. + * Internal shard state, similar to a DOMStore, but optimized for use in the actor system, e.g. it does not expose + * public interfaces and assumes it is only ever called from a single thread. * - * This class is not part of the API contract and is subject to change at any time. + *

+ * This class is not part of the API contract and is subject to change at any time. It is NOT thread-safe. */ -@NotThreadSafe public class ShardDataTree extends ShardDataTreeTransactionParent { + private static final class CommitEntry { + final SimpleShardDataTreeCohort cohort; + long lastAccess; + + CommitEntry(final SimpleShardDataTreeCohort cohort, final long now) { + this.cohort = requireNonNull(cohort); + lastAccess = now; + } + + @Override + public String toString() { + return "CommitEntry [tx=" + cohort.getIdentifier() + ", state=" + cohort.getState() + "]"; + } + } + + private static final Timeout COMMIT_STEP_TIMEOUT = new Timeout(FiniteDuration.create(5, TimeUnit.SECONDS)); private static final Logger LOG = LoggerFactory.getLogger(ShardDataTree.class); - private static final YangInstanceIdentifier ROOT_PATH = YangInstanceIdentifier.builder().build(); - private static final ShardDataTreeNotificationManager MANAGER = new ShardDataTreeNotificationManager(); - private final Map transactionChains = new HashMap<>(); - private final ShardDataTreeChangePublisher treeChangePublisher = new ShardDataTreeChangePublisher(); - private final ListenerTree listenerTree = ListenerTree.create(); - private final TipProducingDataTree dataTree; + + /** + * Process this many transactions in a single batched run. If we exceed this limit, we need to schedule later + * execution to finish up the batch. This is necessary in case of a long list of transactions which progress + * immediately through their preCommit phase -- if that happens, their completion eats up stack frames and could + * result in StackOverflowError. + */ + private static final int MAX_TRANSACTION_BATCH = 100; + + private final Map transactionChains = new HashMap<>(); + private final DataTreeCohortActorRegistry cohortRegistry = new DataTreeCohortActorRegistry(); + private final Deque pendingTransactions = new ArrayDeque<>(); + private final Queue pendingCommits = new ArrayDeque<>(); + private final Queue pendingFinishCommits = new ArrayDeque<>(); + + /** + * Callbacks that need to be invoked once a payload is replicated. + */ + private final Map replicationCallbacks = new HashMap<>(); + + private final ShardDataTreeChangeListenerPublisher treeChangeListenerPublisher; + private final Collection> metadata; + private final DataTree dataTree; + private final String logContext; + private final Shard shard; + private Runnable runOnPendingTransactionsComplete; + + /** + * Optimistic {@link DataTreeCandidate} preparation. Since our DataTree implementation is a + * {@link DataTree}, each {@link DataTreeCandidate} is also a {@link DataTreeTip}, e.g. another + * candidate can be prepared on top of it. They still need to be committed in sequence. Here we track the current + * tip of the data tree, which is the last DataTreeCandidate we have in flight, or the DataTree itself. + */ + private DataTreeTip tip; + private SchemaContext schemaContext; + private DataSchemaContextTree dataSchemaContext; - public ShardDataTree(final SchemaContext schemaContext, final TreeType treeType) { - dataTree = InMemoryDataTreeFactory.getInstance().create(treeType); + private int currentTransactionBatch; + + ShardDataTree(final Shard shard, final SchemaContext schemaContext, final DataTree dataTree, + final ShardDataTreeChangeListenerPublisher treeChangeListenerPublisher, + final String logContext, + final ShardDataTreeMetadata... metadata) { + this.dataTree = requireNonNull(dataTree); updateSchemaContext(schemaContext); + + this.shard = requireNonNull(shard); + this.treeChangeListenerPublisher = requireNonNull(treeChangeListenerPublisher); + this.logContext = requireNonNull(logContext); + this.metadata = ImmutableList.copyOf(metadata); + tip = dataTree; } - /** - * @deprecated Use {@link #ShardDataTree(SchemaContext, TreeType)} instead. - */ - @Deprecated - public ShardDataTree(final SchemaContext schemaContext) { - this(schemaContext, TreeType.OPERATIONAL); + ShardDataTree(final Shard shard, final SchemaContext schemaContext, final TreeType treeType, + final YangInstanceIdentifier root, + final ShardDataTreeChangeListenerPublisher treeChangeListenerPublisher, + final String logContext, + final ShardDataTreeMetadata... metadata) { + this(shard, schemaContext, createDataTree(treeType, root), treeChangeListenerPublisher, logContext, metadata); + } + + private static DataTree createDataTree(final TreeType treeType, final YangInstanceIdentifier root) { + final DataTreeConfiguration baseConfig = DataTreeConfiguration.getDefault(treeType); + return new InMemoryDataTreeFactory().create(new DataTreeConfiguration.Builder(baseConfig.getTreeType()) + .setMandatoryNodesValidation(baseConfig.isMandatoryNodesValidationEnabled()) + .setUniqueIndexes(baseConfig.isUniqueIndexEnabled()) + .setRootPath(root) + .build()); + } + + @VisibleForTesting + public ShardDataTree(final Shard shard, final SchemaContext schemaContext, final TreeType treeType) { + this(shard, schemaContext, treeType, YangInstanceIdentifier.empty(), + new DefaultShardDataTreeChangeListenerPublisher(""), ""); + } + + final String logContext() { + return logContext; + } + + final long readTime() { + return shard.ticker().read(); } - public TipProducingDataTree getDataTree() { + public DataTree getDataTree() { return dataTree; } @@ -76,154 +212,1121 @@ public class ShardDataTree extends ShardDataTreeTransactionParent { return schemaContext; } - void updateSchemaContext(final SchemaContext schemaContext) { - Preconditions.checkNotNull(schemaContext); - this.schemaContext = schemaContext; - dataTree.setSchemaContext(schemaContext); + void updateSchemaContext(final SchemaContext newSchemaContext) { + dataTree.setSchemaContext(newSchemaContext); + this.schemaContext = requireNonNull(newSchemaContext); + this.dataSchemaContext = DataSchemaContextTree.from(newSchemaContext); } - private ShardDataTreeTransactionChain ensureTransactionChain(final String chainId) { - ShardDataTreeTransactionChain chain = transactionChains.get(chainId); - if (chain == null) { - chain = new ShardDataTreeTransactionChain(chainId, this); - transactionChains.put(chainId, chain); + void resetTransactionBatch() { + currentTransactionBatch = 0; + } + + /** + * Take a snapshot of current state for later recovery. + * + * @return A state snapshot + */ + @NonNull ShardDataTreeSnapshot takeStateSnapshot() { + final NormalizedNode rootNode = dataTree.takeSnapshot().readNode(YangInstanceIdentifier.empty()).get(); + final Builder>, ShardDataTreeSnapshotMetadata> metaBuilder = + ImmutableMap.builder(); + + for (ShardDataTreeMetadata m : metadata) { + final ShardDataTreeSnapshotMetadata meta = m.toSnapshot(); + if (meta != null) { + metaBuilder.put(meta.getType(), meta); + } } - return chain; + return new MetadataShardDataTreeSnapshot(rootNode, metaBuilder.build()); } - ReadOnlyShardDataTreeTransaction newReadOnlyTransaction(final String txId, final String chainId) { - if (Strings.isNullOrEmpty(chainId)) { - return new ReadOnlyShardDataTreeTransaction(txId, dataTree.takeSnapshot()); + private boolean anyPendingTransactions() { + return !pendingTransactions.isEmpty() || !pendingCommits.isEmpty() || !pendingFinishCommits.isEmpty(); + } + + private void applySnapshot(final @NonNull ShardDataTreeSnapshot snapshot, + final UnaryOperator wrapper) throws DataValidationFailedException { + final Stopwatch elapsed = Stopwatch.createStarted(); + + if (anyPendingTransactions()) { + LOG.warn("{}: applying state snapshot with pending transactions", logContext); } - return ensureTransactionChain(chainId).newReadOnlyTransaction(txId); + final Map>, ShardDataTreeSnapshotMetadata> snapshotMeta; + if (snapshot instanceof MetadataShardDataTreeSnapshot) { + snapshotMeta = ((MetadataShardDataTreeSnapshot) snapshot).getMetadata(); + } else { + snapshotMeta = ImmutableMap.of(); + } + + for (ShardDataTreeMetadata m : metadata) { + final ShardDataTreeSnapshotMetadata s = snapshotMeta.get(m.getSupportedType()); + if (s != null) { + m.applySnapshot(s); + } else { + m.reset(); + } + } + + final DataTreeModification unwrapped = dataTree.takeSnapshot().newModification(); + final DataTreeModification mod = wrapper.apply(unwrapped); + // delete everything first + mod.delete(YangInstanceIdentifier.empty()); + + final Optional> maybeNode = snapshot.getRootNode(); + if (maybeNode.isPresent()) { + // Add everything from the remote node back + mod.write(YangInstanceIdentifier.empty(), maybeNode.get()); + } + mod.ready(); + + dataTree.validate(unwrapped); + DataTreeCandidateTip candidate = dataTree.prepare(unwrapped); + dataTree.commit(candidate); + notifyListeners(candidate); + + LOG.debug("{}: state snapshot applied in {}", logContext, elapsed); } - ReadWriteShardDataTreeTransaction newReadWriteTransaction(final String txId, final String chainId) { - if (Strings.isNullOrEmpty(chainId)) { - return new ReadWriteShardDataTreeTransaction(ShardDataTree.this, txId, dataTree.takeSnapshot() - .newModification()); + /** + * Apply a snapshot coming from the leader. This method assumes the leader and follower SchemaContexts match and + * does not perform any pruning. + * + * @param snapshot Snapshot that needs to be applied + * @throws DataValidationFailedException when the snapshot fails to apply + */ + void applySnapshot(final @NonNull ShardDataTreeSnapshot snapshot) throws DataValidationFailedException { + // TODO: we should be taking ShardSnapshotState here and performing forward-compatibility translation + applySnapshot(snapshot, UnaryOperator.identity()); + } + + /** + * Apply a snapshot coming from recovery. This method does not assume the SchemaContexts match and performs data + * pruning in an attempt to adjust the state to our current SchemaContext. + * + * @param snapshot Snapshot that needs to be applied + * @throws DataValidationFailedException when the snapshot fails to apply + */ + void applyRecoverySnapshot(final @NonNull ShardSnapshotState snapshot) throws DataValidationFailedException { + // TODO: we should be able to reuse the pruner, provided we are not reentrant + final ReusableNormalizedNodePruner pruner = ReusableNormalizedNodePruner.forDataSchemaContext( + dataSchemaContext); + if (snapshot.needsMigration()) { + final ReusableNormalizedNodePruner uintPruner = pruner.withUintAdaption(); + applySnapshot(snapshot.getSnapshot(), + delegate -> new PruningDataTreeModification.Proactive(delegate, dataTree, uintPruner)); + } else { + applySnapshot(snapshot.getSnapshot(), + delegate -> new PruningDataTreeModification.Reactive(delegate, dataTree, pruner)); + } + } + + @SuppressWarnings("checkstyle:IllegalCatch") + private void applyRecoveryCandidate(final CommitTransactionPayload payload) throws IOException { + final Entry entry = payload.getCandidate(); + final DataTreeModification unwrapped = dataTree.takeSnapshot().newModification(); + final PruningDataTreeModification mod = createPruningModification(unwrapped, + NormalizedNodeStreamVersion.MAGNESIUM.compareTo(entry.getValue().getVersion()) > 0); + + DataTreeCandidates.applyToModification(mod, entry.getValue().getCandidate()); + mod.ready(); + LOG.trace("{}: Applying recovery modification {}", logContext, unwrapped); + + try { + dataTree.validate(unwrapped); + dataTree.commit(dataTree.prepare(unwrapped)); + } catch (Exception e) { + File file = new File(System.getProperty("karaf.data", "."), + "failed-recovery-payload-" + logContext + ".out"); + DataTreeModificationOutput.toFile(file, unwrapped); + throw new IllegalStateException(String.format( + "%s: Failed to apply recovery payload. Modification data was written to file %s", + logContext, file), e); } - return ensureTransactionChain(chainId).newReadWriteTransaction(txId); + allMetadataCommittedTransaction(entry.getKey()); } - public void notifyListeners(final DataTreeCandidate candidate) { - LOG.debug("Notifying listeners on candidate {}", candidate); + private PruningDataTreeModification createPruningModification(final DataTreeModification unwrapped, + final boolean uintAdapting) { + // TODO: we should be able to reuse the pruner, provided we are not reentrant + final ReusableNormalizedNodePruner pruner = ReusableNormalizedNodePruner.forDataSchemaContext( + dataSchemaContext); + return uintAdapting ? new PruningDataTreeModification.Proactive(unwrapped, dataTree, pruner.withUintAdaption()) + : new PruningDataTreeModification.Reactive(unwrapped, dataTree, pruner); + } + + /** + * Apply a payload coming from recovery. This method does not assume the SchemaContexts match and performs data + * pruning in an attempt to adjust the state to our current SchemaContext. + * + * @param payload Payload + * @throws IOException when the snapshot fails to deserialize + * @throws DataValidationFailedException when the snapshot fails to apply + */ + void applyRecoveryPayload(final @NonNull Payload payload) throws IOException { + if (payload instanceof CommitTransactionPayload) { + applyRecoveryCandidate((CommitTransactionPayload) payload); + } else if (payload instanceof AbortTransactionPayload) { + allMetadataAbortedTransaction(((AbortTransactionPayload) payload).getIdentifier()); + } else if (payload instanceof PurgeTransactionPayload) { + allMetadataPurgedTransaction(((PurgeTransactionPayload) payload).getIdentifier()); + } else if (payload instanceof CreateLocalHistoryPayload) { + allMetadataCreatedLocalHistory(((CreateLocalHistoryPayload) payload).getIdentifier()); + } else if (payload instanceof CloseLocalHistoryPayload) { + allMetadataClosedLocalHistory(((CloseLocalHistoryPayload) payload).getIdentifier()); + } else if (payload instanceof PurgeLocalHistoryPayload) { + allMetadataPurgedLocalHistory(((PurgeLocalHistoryPayload) payload).getIdentifier()); + } else { + LOG.debug("{}: ignoring unhandled payload {}", logContext, payload); + } + } + + private void applyReplicatedCandidate(final CommitTransactionPayload payload) + throws DataValidationFailedException, IOException { + final Entry entry = payload.getCandidate(); + final TransactionIdentifier identifier = entry.getKey(); + LOG.debug("{}: Applying foreign transaction {}", logContext, identifier); + + final DataTreeModification mod = dataTree.takeSnapshot().newModification(); + // TODO: check version here, which will enable us to perform forward-compatibility transformations + DataTreeCandidates.applyToModification(mod, entry.getValue().getCandidate()); + mod.ready(); + + LOG.trace("{}: Applying foreign modification {}", logContext, mod); + dataTree.validate(mod); + final DataTreeCandidate candidate = dataTree.prepare(mod); + dataTree.commit(candidate); + + allMetadataCommittedTransaction(identifier); + notifyListeners(candidate); + } + + /** + * Apply a payload coming from the leader, which could actually be us. This method assumes the leader and follower + * SchemaContexts match and does not perform any pruning. + * + * @param identifier Payload identifier as returned from RaftActor + * @param payload Payload + * @throws IOException when the snapshot fails to deserialize + * @throws DataValidationFailedException when the snapshot fails to apply + */ + void applyReplicatedPayload(final Identifier identifier, final Payload payload) throws IOException, + DataValidationFailedException { + /* + * This is a bit more involved than it needs to be due to to the fact we do not want to be touching the payload + * if we are the leader and it has originated with us. + * + * The identifier will only ever be non-null when we were the leader which achieved consensus. Unfortunately, + * though, this may not be the case anymore, as we are being called some time afterwards and we may not be + * acting in that capacity anymore. + * + * In any case, we know that this is an entry coming from replication, hence we can be sure we will not observe + * pre-Boron state -- which limits the number of options here. + */ + if (payload instanceof CommitTransactionPayload) { + if (identifier == null) { + applyReplicatedCandidate((CommitTransactionPayload) payload); + } else { + verify(identifier instanceof TransactionIdentifier); + payloadReplicationComplete((TransactionIdentifier) identifier); + } + } else if (payload instanceof AbortTransactionPayload) { + if (identifier != null) { + payloadReplicationComplete((AbortTransactionPayload) payload); + } + allMetadataAbortedTransaction(((AbortTransactionPayload) payload).getIdentifier()); + } else if (payload instanceof PurgeTransactionPayload) { + if (identifier != null) { + payloadReplicationComplete((PurgeTransactionPayload) payload); + } + allMetadataPurgedTransaction(((PurgeTransactionPayload) payload).getIdentifier()); + } else if (payload instanceof CloseLocalHistoryPayload) { + if (identifier != null) { + payloadReplicationComplete((CloseLocalHistoryPayload) payload); + } + allMetadataClosedLocalHistory(((CloseLocalHistoryPayload) payload).getIdentifier()); + } else if (payload instanceof CreateLocalHistoryPayload) { + if (identifier != null) { + payloadReplicationComplete((CreateLocalHistoryPayload)payload); + } + allMetadataCreatedLocalHistory(((CreateLocalHistoryPayload) payload).getIdentifier()); + } else if (payload instanceof PurgeLocalHistoryPayload) { + if (identifier != null) { + payloadReplicationComplete((PurgeLocalHistoryPayload)payload); + } + allMetadataPurgedLocalHistory(((PurgeLocalHistoryPayload) payload).getIdentifier()); + } else { + LOG.warn("{}: ignoring unhandled identifier {} payload {}", logContext, identifier, payload); + } + } - // DataTreeChanges first, as they are more light-weight - treeChangePublisher.publishChanges(candidate); + private void replicatePayload(final Identifier id, final Payload payload, final @Nullable Runnable callback) { + if (callback != null) { + replicationCallbacks.put(payload, callback); + } + shard.persistPayload(id, payload, true); + } + + private void payloadReplicationComplete(final AbstractIdentifiablePayload payload) { + final Runnable callback = replicationCallbacks.remove(payload); + if (callback != null) { + LOG.debug("{}: replication of {} completed, invoking {}", logContext, payload.getIdentifier(), callback); + callback.run(); + } else { + LOG.debug("{}: replication of {} has no callback", logContext, payload.getIdentifier()); + } + } + + private void payloadReplicationComplete(final TransactionIdentifier txId) { + final CommitEntry current = pendingFinishCommits.peek(); + if (current == null) { + LOG.warn("{}: No outstanding transactions, ignoring consensus on transaction {}", logContext, txId); + allMetadataCommittedTransaction(txId); + return; + } + + if (!current.cohort.getIdentifier().equals(txId)) { + LOG.debug("{}: Head of pendingFinishCommits queue is {}, ignoring consensus on transaction {}", logContext, + current.cohort.getIdentifier(), txId); + allMetadataCommittedTransaction(txId); + return; + } + + finishCommit(current.cohort); + } + + private void allMetadataAbortedTransaction(final TransactionIdentifier txId) { + for (ShardDataTreeMetadata m : metadata) { + m.onTransactionAborted(txId); + } + } + + private void allMetadataCommittedTransaction(final TransactionIdentifier txId) { + for (ShardDataTreeMetadata m : metadata) { + m.onTransactionCommitted(txId); + } + } + + private void allMetadataPurgedTransaction(final TransactionIdentifier txId) { + for (ShardDataTreeMetadata m : metadata) { + m.onTransactionPurged(txId); + } + } + + private void allMetadataCreatedLocalHistory(final LocalHistoryIdentifier historyId) { + for (ShardDataTreeMetadata m : metadata) { + m.onHistoryCreated(historyId); + } + } + + private void allMetadataClosedLocalHistory(final LocalHistoryIdentifier historyId) { + for (ShardDataTreeMetadata m : metadata) { + m.onHistoryClosed(historyId); + } + } + + private void allMetadataPurgedLocalHistory(final LocalHistoryIdentifier historyId) { + for (ShardDataTreeMetadata m : metadata) { + m.onHistoryPurged(historyId); + } + } - // DataChanges second, as they are heavier - ResolveDataChangeEventsTask.create(candidate, listenerTree).resolve(MANAGER); + /** + * Create a transaction chain for specified history. Unlike {@link #ensureTransactionChain(LocalHistoryIdentifier)}, + * this method is used for re-establishing state when we are taking over + * + * @param historyId Local history identifier + * @param closed True if the chain should be created in closed state (i.e. pending purge) + * @return Transaction chain handle + */ + ShardDataTreeTransactionChain recreateTransactionChain(final LocalHistoryIdentifier historyId, + final boolean closed) { + final ShardDataTreeTransactionChain ret = new ShardDataTreeTransactionChain(historyId, this); + final ShardDataTreeTransactionChain existing = transactionChains.putIfAbsent(historyId, ret); + checkState(existing == null, "Attempted to recreate chain %s, but %s already exists", historyId, existing); + return ret; } - void notifyOfInitialData(DataChangeListenerRegistration>> listenerReg, Optional currentState) { + ShardDataTreeTransactionChain ensureTransactionChain(final LocalHistoryIdentifier historyId, + final @Nullable Runnable callback) { + ShardDataTreeTransactionChain chain = transactionChains.get(historyId); + if (chain == null) { + chain = new ShardDataTreeTransactionChain(historyId, this); + transactionChains.put(historyId, chain); + replicatePayload(historyId, CreateLocalHistoryPayload.create( + historyId, shard.getDatastoreContext().getInitialPayloadSerializedBufferCapacity()), callback); + } else if (callback != null) { + callback.run(); + } - if(currentState.isPresent()) { - ListenerTree localListenerTree = ListenerTree.create(); - localListenerTree.registerDataChangeListener(listenerReg.getPath(), listenerReg.getInstance(), - listenerReg.getScope()); + return chain; + } - ResolveDataChangeEventsTask.create(currentState.get(), localListenerTree).resolve(MANAGER); + ReadOnlyShardDataTreeTransaction newReadOnlyTransaction(final TransactionIdentifier txId) { + shard.getShardMBean().incrementReadOnlyTransactionCount(); + + if (txId.getHistoryId().getHistoryId() == 0) { + return new ReadOnlyShardDataTreeTransaction(this, txId, dataTree.takeSnapshot()); } + + return ensureTransactionChain(txId.getHistoryId(), null).newReadOnlyTransaction(txId); } - void notifyOfInitialData(final YangInstanceIdentifier path, final DOMDataTreeChangeListener listener, - final Optional currentState) { - if(currentState.isPresent()) { - ShardDataTreeChangePublisher localTreeChangePublisher = new ShardDataTreeChangePublisher(); - localTreeChangePublisher.registerTreeChangeListener(path, listener); - localTreeChangePublisher.publishChanges(currentState.get()); + ReadWriteShardDataTreeTransaction newReadWriteTransaction(final TransactionIdentifier txId) { + shard.getShardMBean().incrementReadWriteTransactionCount(); + + if (txId.getHistoryId().getHistoryId() == 0) { + return new ReadWriteShardDataTreeTransaction(ShardDataTree.this, txId, dataTree.takeSnapshot() + .newModification()); } + + return ensureTransactionChain(txId.getHistoryId(), null).newReadWriteTransaction(txId); } - void closeAllTransactionChains() { + @VisibleForTesting + public void notifyListeners(final DataTreeCandidate candidate) { + treeChangeListenerPublisher.publishChanges(candidate); + } + + /** + * Immediately purge all state relevant to leader. This includes all transaction chains and any scheduled + * replication callbacks. + */ + void purgeLeaderState() { for (ShardDataTreeTransactionChain chain : transactionChains.values()) { chain.close(); } transactionChains.clear(); + replicationCallbacks.clear(); } - void closeTransactionChain(final String transactionChainId) { - final ShardDataTreeTransactionChain chain = transactionChains.remove(transactionChainId); - if (chain != null) { - chain.close(); - } else { - LOG.debug("Closing non-existent transaction chain {}", transactionChainId); + /** + * Close a single transaction chain. + * + * @param id History identifier + * @param callback Callback to invoke upon completion, may be null + */ + void closeTransactionChain(final LocalHistoryIdentifier id, final @Nullable Runnable callback) { + if (commonCloseTransactionChain(id, callback)) { + replicatePayload(id, CloseLocalHistoryPayload.create(id, + shard.getDatastoreContext().getInitialPayloadSerializedBufferCapacity()), callback); } } - Entry>>, - Optional> registerChangeListener(final YangInstanceIdentifier path, - final AsyncDataChangeListener> listener, - final DataChangeScope scope) { - final DataChangeListenerRegistration>> reg = - listenerTree.registerDataChangeListener(path, listener, scope); - - return new SimpleEntry<>(reg, readCurrentData()); + /** + * Close a single transaction chain which is received through ask-based protocol. It does not keep a commit record. + * + * @param id History identifier + */ + void closeTransactionChain(final LocalHistoryIdentifier id) { + commonCloseTransactionChain(id, null); } - private Optional readCurrentData() { - final Optional> currentState = dataTree.takeSnapshot().readNode(ROOT_PATH); - return currentState.isPresent() ? Optional.of(DataTreeCandidates.fromNormalizedNode( - ROOT_PATH, currentState.get())) : Optional.absent(); + private boolean commonCloseTransactionChain(final LocalHistoryIdentifier id, final @Nullable Runnable callback) { + final ShardDataTreeTransactionChain chain = transactionChains.get(id); + if (chain == null) { + LOG.debug("{}: Closing non-existent transaction chain {}", logContext, id); + if (callback != null) { + callback.run(); + } + return false; + } + + chain.close(); + return true; } - public Entry, Optional> registerTreeChangeListener( - final YangInstanceIdentifier path, final DOMDataTreeChangeListener listener) { - final ListenerRegistration reg = treeChangePublisher.registerTreeChangeListener( - path, listener); + /** + * Purge a single transaction chain. + * + * @param id History identifier + * @param callback Callback to invoke upon completion, may be null + */ + void purgeTransactionChain(final LocalHistoryIdentifier id, final @Nullable Runnable callback) { + final ShardDataTreeTransactionChain chain = transactionChains.remove(id); + if (chain == null) { + LOG.debug("{}: Purging non-existent transaction chain {}", logContext, id); + if (callback != null) { + callback.run(); + } + return; + } - return new SimpleEntry<>(reg, readCurrentData()); + replicatePayload(id, PurgeLocalHistoryPayload.create( + id, shard.getDatastoreContext().getInitialPayloadSerializedBufferCapacity()), callback); } - void applyForeignCandidate(final String identifier, final DataTreeCandidate foreign) throws DataValidationFailedException { - LOG.debug("Applying foreign transaction {}", identifier); + Optional readCurrentData() { + return dataTree.takeSnapshot().readNode(YangInstanceIdentifier.empty()) + .map(state -> DataTreeCandidates.fromNormalizedNode(YangInstanceIdentifier.empty(), state)); + } - final DataTreeModification mod = dataTree.takeSnapshot().newModification(); - DataTreeCandidates.applyToModification(mod, foreign); - mod.ready(); + public void registerTreeChangeListener(final YangInstanceIdentifier path, final DOMDataTreeChangeListener listener, + final Optional initialState, + final Consumer> onRegistration) { + treeChangeListenerPublisher.registerTreeChangeListener(path, listener, initialState, onRegistration); + } - LOG.trace("Applying foreign modification {}", mod); - dataTree.validate(mod); - final DataTreeCandidate candidate = dataTree.prepare(mod); - dataTree.commit(candidate); - notifyListeners(candidate); + int getQueueSize() { + return pendingTransactions.size() + pendingCommits.size() + pendingFinishCommits.size(); } @Override - void abortTransaction(final AbstractShardDataTreeTransaction transaction) { - // Intentional no-op + void abortTransaction(final AbstractShardDataTreeTransaction transaction, final Runnable callback) { + final TransactionIdentifier id = transaction.getIdentifier(); + LOG.debug("{}: aborting transaction {}", logContext, id); + replicatePayload(id, AbortTransactionPayload.create( + id, shard.getDatastoreContext().getInitialPayloadSerializedBufferCapacity()), callback); } @Override - ShardDataTreeCohort finishTransaction(final ReadWriteShardDataTreeTransaction transaction) { + void abortFromTransactionActor(final AbstractShardDataTreeTransaction transaction) { + // No-op for free-standing transactions + + } + + @Override + ShardDataTreeCohort finishTransaction(final ReadWriteShardDataTreeTransaction transaction, + final Optional> participatingShardNames) { final DataTreeModification snapshot = transaction.getSnapshot(); + final TransactionIdentifier id = transaction.getIdentifier(); + LOG.debug("{}: readying transaction {}", logContext, id); snapshot.ready(); - return new SimpleShardDataTreeCohort(this, snapshot, transaction.getId()); + LOG.debug("{}: transaction {} ready", logContext, id); + + return createReadyCohort(transaction.getIdentifier(), snapshot, participatingShardNames); } - public Optional> readNode(YangInstanceIdentifier path) { + void purgeTransaction(final TransactionIdentifier id, final Runnable callback) { + LOG.debug("{}: purging transaction {}", logContext, id); + replicatePayload(id, PurgeTransactionPayload.create( + id, shard.getDatastoreContext().getInitialPayloadSerializedBufferCapacity()), callback); + } + + public Optional> readNode(final YangInstanceIdentifier path) { return dataTree.takeSnapshot().readNode(path); } - public DataTreeSnapshot takeSnapshot() { + DataTreeSnapshot takeSnapshot() { return dataTree.takeSnapshot(); } + @VisibleForTesting public DataTreeModification newModification() { return dataTree.takeSnapshot().newModification(); } - public DataTreeCandidate commit(DataTreeModification modification) throws DataValidationFailedException { - modification.ready(); - dataTree.validate(modification); - DataTreeCandidateTip candidate = dataTree.prepare(modification); - dataTree.commit(candidate); - return candidate; + public Collection getAndClearPendingTransactions() { + Collection ret = new ArrayList<>(getQueueSize()); + + for (CommitEntry entry: pendingFinishCommits) { + ret.add(entry.cohort); + } + + for (CommitEntry entry: pendingCommits) { + ret.add(entry.cohort); + } + + for (CommitEntry entry: pendingTransactions) { + ret.add(entry.cohort); + } + + pendingFinishCommits.clear(); + pendingCommits.clear(); + pendingTransactions.clear(); + tip = dataTree; + return ret; + } + + /** + * Called some time after {@link #processNextPendingTransaction()} decides to stop processing. + */ + void resumeNextPendingTransaction() { + LOG.debug("{}: attempting to resume transaction processing", logContext); + processNextPending(); + } + + @SuppressWarnings("checkstyle:IllegalCatch") + private void processNextPendingTransaction() { + ++currentTransactionBatch; + if (currentTransactionBatch > MAX_TRANSACTION_BATCH) { + LOG.debug("{}: Already processed {}, scheduling continuation", logContext, currentTransactionBatch); + shard.scheduleNextPendingTransaction(); + return; + } + + processNextPending(pendingTransactions, State.CAN_COMMIT_PENDING, entry -> { + final SimpleShardDataTreeCohort cohort = entry.cohort; + final DataTreeModification modification = cohort.getDataTreeModification(); + + LOG.debug("{}: Validating transaction {}", logContext, cohort.getIdentifier()); + Exception cause; + try { + tip.validate(modification); + LOG.debug("{}: Transaction {} validated", logContext, cohort.getIdentifier()); + cohort.successfulCanCommit(); + entry.lastAccess = readTime(); + return; + } catch (ConflictingModificationAppliedException e) { + LOG.warn("{}: Store Tx {}: Conflicting modification for path {}.", logContext, cohort.getIdentifier(), + e.getPath()); + cause = new OptimisticLockFailedException("Optimistic lock failed for path " + e.getPath(), e); + } catch (DataValidationFailedException e) { + LOG.warn("{}: Store Tx {}: Data validation failed for path {}.", logContext, cohort.getIdentifier(), + e.getPath(), e); + + // For debugging purposes, allow dumping of the modification. Coupled with the above + // precondition log, it should allow us to understand what went on. + LOG.debug("{}: Store Tx {}: modifications: {}", logContext, cohort.getIdentifier(), modification); + LOG.trace("{}: Current tree: {}", logContext, dataTree); + cause = new TransactionCommitFailedException("Data did not pass validation for path " + e.getPath(), e); + } catch (Exception e) { + LOG.warn("{}: Unexpected failure in validation phase", logContext, e); + cause = e; + } + + // Failure path: propagate the failure, remove the transaction from the queue and loop to the next one + pendingTransactions.poll().cohort.failedCanCommit(cause); + }); + } + + private void processNextPending() { + processNextPendingCommit(); + processNextPendingTransaction(); + } + + private void processNextPending(final Queue queue, final State allowedState, + final Consumer processor) { + while (!queue.isEmpty()) { + final CommitEntry entry = queue.peek(); + final SimpleShardDataTreeCohort cohort = entry.cohort; + + if (cohort.isFailed()) { + LOG.debug("{}: Removing failed transaction {}", logContext, cohort.getIdentifier()); + queue.remove(); + continue; + } + + if (cohort.getState() == allowedState) { + processor.accept(entry); + } + + break; + } + + maybeRunOperationOnPendingTransactionsComplete(); + } + + private void processNextPendingCommit() { + processNextPending(pendingCommits, State.COMMIT_PENDING, + entry -> startCommit(entry.cohort, entry.cohort.getCandidate())); + } + + private boolean peekNextPendingCommit() { + final CommitEntry first = pendingCommits.peek(); + return first != null && first.cohort.getState() == State.COMMIT_PENDING; + } + + void startCanCommit(final SimpleShardDataTreeCohort cohort) { + final CommitEntry head = pendingTransactions.peek(); + if (head == null) { + LOG.warn("{}: No transactions enqueued while attempting to start canCommit on {}", logContext, cohort); + return; + } + if (!cohort.equals(head.cohort)) { + // The tx isn't at the head of the queue so we can't start canCommit at this point. Here we check if this + // tx should be moved ahead of other tx's in the READY state in the pendingTransactions queue. If this tx + // has other participating shards, it could deadlock with other tx's accessing the same shards + // depending on the order the tx's are readied on each shard + // (see https://jira.opendaylight.org/browse/CONTROLLER-1836). Therefore, if the preceding participating + // shard names for a preceding pending tx, call it A, in the queue matches that of this tx, then this tx + // is allowed to be moved ahead of tx A in the queue so it is processed first to avoid potential deadlock + // if tx A is behind this tx in the pendingTransactions queue for a preceding shard. In other words, since + // canCommmit for this tx was requested before tx A, honor that request. If this tx is moved to the head of + // the queue as a result, then proceed with canCommit. + + Collection precedingShardNames = extractPrecedingShardNames(cohort.getParticipatingShardNames()); + if (precedingShardNames.isEmpty()) { + LOG.debug("{}: Tx {} is scheduled for canCommit step", logContext, cohort.getIdentifier()); + return; + } + + LOG.debug("{}: Evaluating tx {} for canCommit - preceding participating shard names {}", + logContext, cohort.getIdentifier(), precedingShardNames); + final Iterator iter = pendingTransactions.iterator(); + int index = -1; + int moveToIndex = -1; + while (iter.hasNext()) { + final CommitEntry entry = iter.next(); + ++index; + + if (cohort.equals(entry.cohort)) { + if (moveToIndex < 0) { + LOG.debug("{}: Not moving tx {} - cannot proceed with canCommit", + logContext, cohort.getIdentifier()); + return; + } + + LOG.debug("{}: Moving {} to index {} in the pendingTransactions queue", + logContext, cohort.getIdentifier(), moveToIndex); + iter.remove(); + insertEntry(pendingTransactions, entry, moveToIndex); + + if (!cohort.equals(pendingTransactions.peek().cohort)) { + LOG.debug("{}: Tx {} is not at the head of the queue - cannot proceed with canCommit", + logContext, cohort.getIdentifier()); + return; + } + + LOG.debug("{}: Tx {} is now at the head of the queue - proceeding with canCommit", + logContext, cohort.getIdentifier()); + break; + } + + if (entry.cohort.getState() != State.READY) { + LOG.debug("{}: Skipping pending transaction {} in state {}", + logContext, entry.cohort.getIdentifier(), entry.cohort.getState()); + continue; + } + + final Collection pendingPrecedingShardNames = extractPrecedingShardNames( + entry.cohort.getParticipatingShardNames()); + + if (precedingShardNames.equals(pendingPrecedingShardNames)) { + if (moveToIndex < 0) { + LOG.debug("{}: Preceding shard names {} for pending tx {} match - saving moveToIndex {}", + logContext, pendingPrecedingShardNames, entry.cohort.getIdentifier(), index); + moveToIndex = index; + } else { + LOG.debug( + "{}: Preceding shard names {} for pending tx {} match but moveToIndex already set to {}", + logContext, pendingPrecedingShardNames, entry.cohort.getIdentifier(), moveToIndex); + } + } else { + LOG.debug("{}: Preceding shard names {} for pending tx {} differ - skipping", + logContext, pendingPrecedingShardNames, entry.cohort.getIdentifier()); + } + } + } + + processNextPendingTransaction(); + } + + private static void insertEntry(final Deque queue, final CommitEntry entry, final int atIndex) { + if (atIndex == 0) { + queue.addFirst(entry); + return; + } + + LOG.trace("Inserting into Deque at index {}", atIndex); + + Deque tempStack = new ArrayDeque<>(atIndex); + for (int i = 0; i < atIndex; i++) { + tempStack.push(queue.poll()); + } + + queue.addFirst(entry); + + tempStack.forEach(queue::addFirst); + } + + private Collection extractPrecedingShardNames(final Optional> participatingShardNames) { + return participatingShardNames.map((Function, Collection>) + set -> set.headSet(shard.getShardName())).orElse(Collections.emptyList()); + } + + private void failPreCommit(final Throwable cause) { + shard.getShardMBean().incrementFailedTransactionsCount(); + pendingTransactions.poll().cohort.failedPreCommit(cause); + processNextPendingTransaction(); + } + + @SuppressWarnings("checkstyle:IllegalCatch") + void startPreCommit(final SimpleShardDataTreeCohort cohort) { + final CommitEntry entry = pendingTransactions.peek(); + checkState(entry != null, "Attempted to pre-commit of %s when no transactions pending", cohort); + + final SimpleShardDataTreeCohort current = entry.cohort; + verify(cohort.equals(current), "Attempted to pre-commit %s while %s is pending", cohort, current); + + final TransactionIdentifier currentId = current.getIdentifier(); + LOG.debug("{}: Preparing transaction {}", logContext, currentId); + + final DataTreeCandidateTip candidate; + try { + candidate = tip.prepare(cohort.getDataTreeModification()); + LOG.debug("{}: Transaction {} candidate ready", logContext, currentId); + } catch (DataValidationFailedException | RuntimeException e) { + failPreCommit(e); + return; + } + + cohort.userPreCommit(candidate, new FutureCallback() { + @Override + public void onSuccess(final Void noop) { + // Set the tip of the data tree. + tip = verifyNotNull(candidate); + + entry.lastAccess = readTime(); + + pendingTransactions.remove(); + pendingCommits.add(entry); + + LOG.debug("{}: Transaction {} prepared", logContext, currentId); + + cohort.successfulPreCommit(candidate); + + processNextPendingTransaction(); + } + + @Override + public void onFailure(final Throwable failure) { + failPreCommit(failure); + } + }); + } + + private void failCommit(final Exception cause) { + shard.getShardMBean().incrementFailedTransactionsCount(); + pendingFinishCommits.poll().cohort.failedCommit(cause); + processNextPending(); + } + + @SuppressWarnings("checkstyle:IllegalCatch") + private void finishCommit(final SimpleShardDataTreeCohort cohort) { + final TransactionIdentifier txId = cohort.getIdentifier(); + final DataTreeCandidate candidate = cohort.getCandidate(); + + LOG.debug("{}: Resuming commit of transaction {}", logContext, txId); + + if (tip == candidate) { + // All pending candidates have been committed, reset the tip to the data tree. + tip = dataTree; + } + + try { + dataTree.commit(candidate); + } catch (Exception e) { + LOG.error("{}: Failed to commit transaction {}", logContext, txId, e); + failCommit(e); + return; + } + + allMetadataCommittedTransaction(txId); + shard.getShardMBean().incrementCommittedTransactionCount(); + shard.getShardMBean().setLastCommittedTransactionTime(System.currentTimeMillis()); + + // FIXME: propagate journal index + pendingFinishCommits.poll().cohort.successfulCommit(UnsignedLong.ZERO, () -> { + LOG.trace("{}: Transaction {} committed, proceeding to notify", logContext, txId); + notifyListeners(candidate); + + processNextPending(); + }); + } + + void startCommit(final SimpleShardDataTreeCohort cohort, final DataTreeCandidate candidate) { + final CommitEntry entry = pendingCommits.peek(); + checkState(entry != null, "Attempted to start commit of %s when no transactions pending", cohort); + + final SimpleShardDataTreeCohort current = entry.cohort; + if (!cohort.equals(current)) { + LOG.debug("{}: Transaction {} scheduled for commit step", logContext, cohort.getIdentifier()); + return; + } + + LOG.debug("{}: Starting commit for transaction {}", logContext, current.getIdentifier()); + + final TransactionIdentifier txId = cohort.getIdentifier(); + final Payload payload; + try { + payload = CommitTransactionPayload.create(txId, candidate, PayloadVersion.current(), + shard.getDatastoreContext().getInitialPayloadSerializedBufferCapacity()); + } catch (IOException e) { + LOG.error("{}: Failed to encode transaction {} candidate {}", logContext, txId, candidate, e); + pendingCommits.poll().cohort.failedCommit(e); + processNextPending(); + return; + } + + // We process next transactions pending canCommit before we call persistPayload to possibly progress subsequent + // transactions to the COMMIT_PENDING state so the payloads can be batched for replication. This is done for + // single-shard transactions that immediately transition from canCommit to preCommit to commit. Note that + // if the next pending transaction is progressed to COMMIT_PENDING and this method (startCommit) is called, + // the next transaction will not attempt to replicate b/c the current transaction is still at the head of the + // pendingCommits queue. + processNextPendingTransaction(); + + // After processing next pending transactions, we can now remove the current transaction from pendingCommits. + // Note this must be done before the call to peekNextPendingCommit below so we check the next transaction + // in order to properly determine the batchHint flag for the call to persistPayload. + pendingCommits.remove(); + pendingFinishCommits.add(entry); + + // See if the next transaction is pending commit (ie in the COMMIT_PENDING state) so it can be batched with + // this transaction for replication. + boolean replicationBatchHint = peekNextPendingCommit(); + + // Once completed, we will continue via payloadReplicationComplete + shard.persistPayload(txId, payload, replicationBatchHint); + + entry.lastAccess = shard.ticker().read(); + + LOG.debug("{}: Transaction {} submitted to persistence", logContext, txId); + + // Process the next transaction pending commit, if any. If there is one it will be batched with this + // transaction for replication. + processNextPendingCommit(); + } + + Collection getCohortActors() { + return cohortRegistry.getCohortActors(); + } + + void processCohortRegistryCommand(final ActorRef sender, final CohortRegistryCommand message) { + cohortRegistry.process(sender, message); + } + + @Override + ShardDataTreeCohort createFailedCohort(final TransactionIdentifier txId, final DataTreeModification mod, + final Exception failure) { + final SimpleShardDataTreeCohort cohort = new SimpleShardDataTreeCohort(this, mod, txId, failure); + pendingTransactions.add(new CommitEntry(cohort, readTime())); + return cohort; + } + + @Override + ShardDataTreeCohort createReadyCohort(final TransactionIdentifier txId, final DataTreeModification mod, + final Optional> participatingShardNames) { + SimpleShardDataTreeCohort cohort = new SimpleShardDataTreeCohort(this, mod, txId, + cohortRegistry.createCohort(schemaContext, txId, shard::executeInSelf, + COMMIT_STEP_TIMEOUT), participatingShardNames); + pendingTransactions.add(new CommitEntry(cohort, readTime())); + return cohort; + } + + // Exposed for ShardCommitCoordinator so it does not have deal with local histories (it does not care), this mimics + // the newReadWriteTransaction() + ShardDataTreeCohort newReadyCohort(final TransactionIdentifier txId, final DataTreeModification mod, + final Optional> participatingShardNames) { + if (txId.getHistoryId().getHistoryId() == 0) { + return createReadyCohort(txId, mod, participatingShardNames); + } + + return ensureTransactionChain(txId.getHistoryId(), null).createReadyCohort(txId, mod, participatingShardNames); + } + + @SuppressFBWarnings(value = "DB_DUPLICATE_SWITCH_CLAUSES", justification = "See inline comments below.") + void checkForExpiredTransactions(final long transactionCommitTimeoutMillis, + final Function accessTimeUpdater) { + final long timeout = TimeUnit.MILLISECONDS.toNanos(transactionCommitTimeoutMillis); + final long now = readTime(); + + final Queue currentQueue = !pendingFinishCommits.isEmpty() ? pendingFinishCommits : + !pendingCommits.isEmpty() ? pendingCommits : pendingTransactions; + final CommitEntry currentTx = currentQueue.peek(); + if (currentTx == null) { + // Empty queue, no-op + return; + } + + long delta = now - currentTx.lastAccess; + if (delta < timeout) { + // Not expired yet, bail + return; + } + + final OptionalLong updateOpt = accessTimeUpdater.apply(currentTx.cohort); + if (updateOpt.isPresent()) { + final long newAccess = updateOpt.getAsLong(); + final long newDelta = now - newAccess; + if (newDelta < delta) { + LOG.debug("{}: Updated current transaction {} access time", logContext, + currentTx.cohort.getIdentifier()); + currentTx.lastAccess = newAccess; + delta = newDelta; + } + + if (delta < timeout) { + // Not expired yet, bail + return; + } + } + + final long deltaMillis = TimeUnit.NANOSECONDS.toMillis(delta); + final State state = currentTx.cohort.getState(); + + LOG.warn("{}: Current transaction {} has timed out after {} ms in state {}", logContext, + currentTx.cohort.getIdentifier(), deltaMillis, state); + boolean processNext = true; + final TimeoutException cohortFailure = new TimeoutException("Backend timeout in state " + state + " after " + + deltaMillis + "ms"); + + switch (state) { + case CAN_COMMIT_PENDING: + currentQueue.remove().cohort.failedCanCommit(cohortFailure); + break; + case CAN_COMMIT_COMPLETE: + // The suppression of the FindBugs "DB_DUPLICATE_SWITCH_CLAUSES" warning pertains to this clause + // whose code is duplicated with PRE_COMMIT_COMPLETE. The clauses aren't combined in case the code + // in PRE_COMMIT_COMPLETE is changed. + currentQueue.remove().cohort.reportFailure(cohortFailure); + break; + case PRE_COMMIT_PENDING: + currentQueue.remove().cohort.failedPreCommit(cohortFailure); + break; + case PRE_COMMIT_COMPLETE: + // FIXME: this is a legacy behavior problem. Three-phase commit protocol specifies that after we + // are ready we should commit the transaction, not abort it. Our current software stack does + // not allow us to do that consistently, because we persist at the time of commit, hence + // we can end up in a state where we have pre-committed a transaction, then a leader failover + // occurred ... the new leader does not see the pre-committed transaction and does not have + // a running timer. To fix this we really need two persistence events. + // + // The first one, done at pre-commit time will hold the transaction payload. When consensus + // is reached, we exit the pre-commit phase and start the pre-commit timer. Followers do not + // apply the state in this event. + // + // The second one, done at commit (or abort) time holds only the transaction identifier and + // signals to followers that the state should (or should not) be applied. + // + // In order to make the pre-commit timer working across failovers, though, we need + // a per-shard cluster-wide monotonic time, so a follower becoming the leader can accurately + // restart the timer. + currentQueue.remove().cohort.reportFailure(cohortFailure); + break; + case COMMIT_PENDING: + LOG.warn("{}: Transaction {} is still committing, cannot abort", logContext, + currentTx.cohort.getIdentifier()); + currentTx.lastAccess = now; + processNext = false; + return; + case READY: + currentQueue.remove().cohort.reportFailure(cohortFailure); + break; + case ABORTED: + case COMMITTED: + case FAILED: + default: + currentQueue.remove(); + } + + if (processNext) { + processNextPending(); + } + } + + boolean startAbort(final SimpleShardDataTreeCohort cohort) { + final Iterator it = Iterables.concat(pendingFinishCommits, pendingCommits, + pendingTransactions).iterator(); + if (!it.hasNext()) { + LOG.debug("{}: no open transaction while attempting to abort {}", logContext, cohort.getIdentifier()); + return true; + } + + // First entry is special, as it may already be committing + final CommitEntry first = it.next(); + if (cohort.equals(first.cohort)) { + if (cohort.getState() != State.COMMIT_PENDING) { + LOG.debug("{}: aborting head of queue {} in state {}", logContext, cohort.getIdentifier(), + cohort.getIdentifier()); + + it.remove(); + if (cohort.getCandidate() != null) { + rebaseTransactions(it, dataTree); + } + + processNextPending(); + return true; + } + + LOG.warn("{}: transaction {} is committing, skipping abort", logContext, cohort.getIdentifier()); + return false; + } + + DataTreeTip newTip = MoreObjects.firstNonNull(first.cohort.getCandidate(), dataTree); + while (it.hasNext()) { + final CommitEntry e = it.next(); + if (cohort.equals(e.cohort)) { + LOG.debug("{}: aborting queued transaction {}", logContext, cohort.getIdentifier()); + + it.remove(); + if (cohort.getCandidate() != null) { + rebaseTransactions(it, newTip); + } + + return true; + } else { + newTip = MoreObjects.firstNonNull(e.cohort.getCandidate(), newTip); + } + } + + LOG.debug("{}: aborted transaction {} not found in the queue", logContext, cohort.getIdentifier()); + return true; + } + + @SuppressWarnings("checkstyle:IllegalCatch") + private void rebaseTransactions(final Iterator iter, final @NonNull DataTreeTip newTip) { + tip = requireNonNull(newTip); + while (iter.hasNext()) { + final SimpleShardDataTreeCohort cohort = iter.next().cohort; + if (cohort.getState() == State.CAN_COMMIT_COMPLETE) { + LOG.debug("{}: Revalidating queued transaction {}", logContext, cohort.getIdentifier()); + + try { + tip.validate(cohort.getDataTreeModification()); + } catch (DataValidationFailedException | RuntimeException e) { + LOG.debug("{}: Failed to revalidate queued transaction {}", logContext, cohort.getIdentifier(), e); + cohort.reportFailure(e); + } + } else if (cohort.getState() == State.PRE_COMMIT_COMPLETE) { + LOG.debug("{}: Repreparing queued transaction {}", logContext, cohort.getIdentifier()); + + try { + tip.validate(cohort.getDataTreeModification()); + DataTreeCandidateTip candidate = tip.prepare(cohort.getDataTreeModification()); + + cohort.setNewCandidate(candidate); + tip = candidate; + } catch (RuntimeException | DataValidationFailedException e) { + LOG.debug("{}: Failed to reprepare queued transaction {}", logContext, cohort.getIdentifier(), e); + cohort.reportFailure(e); + } + } + } + } + + void setRunOnPendingTransactionsComplete(final Runnable operation) { + runOnPendingTransactionsComplete = operation; + maybeRunOperationOnPendingTransactionsComplete(); + } + + private void maybeRunOperationOnPendingTransactionsComplete() { + if (runOnPendingTransactionsComplete != null && !anyPendingTransactions()) { + LOG.debug("{}: Pending transactions complete - running operation {}", logContext, + runOnPendingTransactionsComplete); + + runOnPendingTransactionsComplete.run(); + runOnPendingTransactionsComplete = null; + } + } + + ShardStats getStats() { + return shard.getShardMBean(); + } + + Iterator cohortIterator() { + return Iterables.transform(Iterables.concat(pendingFinishCommits, pendingCommits, pendingTransactions), + e -> e.cohort).iterator(); + } + + void removeTransactionChain(final LocalHistoryIdentifier id) { + if (transactionChains.remove(id) != null) { + LOG.debug("{}: Removed transaction chain {}", logContext, id); + } } }