--- /dev/null
+/*
+ * Copyright (c) 2016 Cisco Systems, Inc. and others. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.cluster.datastore;
+
+import com.google.common.base.MoreObjects;
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Range;
+import com.google.common.collect.RangeSet;
+import com.google.common.collect.TreeRangeSet;
+import com.google.common.primitives.UnsignedLong;
+import java.util.HashMap;
+import java.util.Map;
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.NotThreadSafe;
+import org.opendaylight.controller.cluster.access.commands.CreateLocalHistoryRequest;
+import org.opendaylight.controller.cluster.access.commands.DeadHistoryException;
+import org.opendaylight.controller.cluster.access.commands.DestroyLocalHistoryRequest;
+import org.opendaylight.controller.cluster.access.commands.LocalHistoryRequest;
+import org.opendaylight.controller.cluster.access.commands.LocalHistorySuccess;
+import org.opendaylight.controller.cluster.access.commands.OutOfOrderRequestException;
+import org.opendaylight.controller.cluster.access.commands.PurgeLocalHistoryRequest;
+import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
+import org.opendaylight.controller.cluster.access.commands.TransactionSuccess;
+import org.opendaylight.controller.cluster.access.commands.UnknownHistoryException;
+import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
+import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
+import org.opendaylight.controller.cluster.access.concepts.RequestEnvelope;
+import org.opendaylight.controller.cluster.access.concepts.RequestException;
+import org.opendaylight.controller.cluster.access.concepts.UnsupportedRequestException;
+import org.opendaylight.yangtools.concepts.Identifiable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Frontend state as observed by the shard leader. This class is responsible for tracking generations and sequencing
+ * in the frontend/backend conversation.
+ *
+ * @author Robert Varga
+ */
+@NotThreadSafe
+final class LeaderFrontendState implements Identifiable<ClientIdentifier> {
+ private static final Logger LOG = LoggerFactory.getLogger(LeaderFrontendState.class);
+
+ // Histories which have not been purged
+ private final Map<LocalHistoryIdentifier, LocalFrontendHistory> localHistories = new HashMap<>();
+
+ // RangeSet performs automatic merging, hence we keep minimal state tracking information
+ private final RangeSet<UnsignedLong> purgedHistories = TreeRangeSet.create();
+
+ // Used for all standalone transactions
+ private final AbstractFrontendHistory standaloneHistory;
+ private final ShardDataTree tree;
+ private final ClientIdentifier clientId;
+ private final String persistenceId;
+
+ private long expectedTxSequence;
+ private Long lastSeenHistory = null;
+
+
+ // TODO: explicit failover notification
+ // Record the ActorRef for the originating actor and when we switch to being a leader send a notification
+ // to the frontend client -- that way it can immediately start sending requests
+
+ // TODO: add statistics:
+ // - number of requests processed
+ // - number of histories processed
+ // - per-RequestException throw counters
+
+ LeaderFrontendState(final String persistenceId, final ClientIdentifier clientId, final ShardDataTree tree) {
+ this.persistenceId = Preconditions.checkNotNull(persistenceId);
+ this.clientId = Preconditions.checkNotNull(clientId);
+ this.tree = Preconditions.checkNotNull(tree);
+ standaloneHistory = new StandaloneFrontendHistory(persistenceId, clientId, tree);
+ }
+
+ @Override
+ public ClientIdentifier getIdentifier() {
+ return clientId;
+ }
+
+ private void checkRequestSequence(final RequestEnvelope envelope) throws OutOfOrderRequestException {
+ if (expectedTxSequence != envelope.getTxSequence()) {
+ throw new OutOfOrderRequestException(expectedTxSequence);
+ }
+ }
+
+ private void expectNextRequest() {
+ expectedTxSequence++;
+ }
+
+ @Nullable LocalHistorySuccess handleLocalHistoryRequest(final LocalHistoryRequest<?> request,
+ final RequestEnvelope envelope) throws RequestException {
+ checkRequestSequence(envelope);
+
+ try {
+ if (request instanceof CreateLocalHistoryRequest) {
+ return handleCreateHistory((CreateLocalHistoryRequest) request);
+ } else if (request instanceof DestroyLocalHistoryRequest) {
+ return handleDestroyHistory((DestroyLocalHistoryRequest) request);
+ } else if (request instanceof PurgeLocalHistoryRequest) {
+ return handlePurgeHistory((PurgeLocalHistoryRequest)request);
+ } else {
+ throw new UnsupportedRequestException(request);
+ }
+ } finally {
+ expectNextRequest();
+ }
+ }
+
+ private LocalHistorySuccess handleCreateHistory(final CreateLocalHistoryRequest request) throws RequestException {
+ final LocalHistoryIdentifier id = request.getTarget();
+ final AbstractFrontendHistory existing = localHistories.get(id);
+ if (existing != null) {
+ // History already exists: report success
+ LOG.debug("{}: history {} already exists", persistenceId, id);
+ return new LocalHistorySuccess(id, request.getSequence());
+ }
+
+ // We have not found the history. Before we create it we need to check history ID sequencing so that we do not
+ // end up resurrecting a purged history.
+ if (purgedHistories.contains(UnsignedLong.fromLongBits(id.getHistoryId()))) {
+ LOG.debug("{}: rejecting purged request {}", persistenceId, request);
+ throw new DeadHistoryException(lastSeenHistory.longValue());
+ }
+
+ // Update last history we have seen
+ if (lastSeenHistory != null && Long.compareUnsigned(lastSeenHistory, id.getHistoryId()) < 0) {
+ lastSeenHistory = id.getHistoryId();
+ }
+
+ localHistories.put(id, new LocalFrontendHistory(persistenceId, tree.ensureTransactionChain(id)));
+ LOG.debug("{}: created history {}", persistenceId, id);
+ return new LocalHistorySuccess(id, request.getSequence());
+ }
+
+ private LocalHistorySuccess handleDestroyHistory(final DestroyLocalHistoryRequest request) throws RequestException {
+ final LocalHistoryIdentifier id = request.getTarget();
+ final LocalFrontendHistory existing = localHistories.get(id);
+ if (existing == null) {
+ // History does not exist: report success
+ LOG.debug("{}: history {} does not exist, nothing to destroy", persistenceId, id);
+ return new LocalHistorySuccess(id, request.getSequence());
+ }
+
+ return existing.destroy(request.getSequence());
+ }
+
+ private LocalHistorySuccess handlePurgeHistory(final PurgeLocalHistoryRequest request) throws RequestException {
+ final LocalHistoryIdentifier id = request.getTarget();
+ final LocalFrontendHistory existing = localHistories.remove(id);
+ if (existing != null) {
+ purgedHistories.add(Range.singleton(UnsignedLong.fromLongBits(id.getHistoryId())));
+
+ if (!existing.isDestroyed()) {
+ LOG.warn("{}: purging undestroyed history {}", persistenceId, id);
+ existing.destroy(request.getSequence());
+ }
+
+ // FIXME: record a PURGE tombstone in the journal
+
+ LOG.debug("{}: purged history {}", persistenceId, id);
+ } else {
+ LOG.debug("{}: history {} has already been purged", persistenceId, id);
+ }
+
+ return new LocalHistorySuccess(id, request.getSequence());
+ }
+
+ @Nullable TransactionSuccess<?> handleTransactionRequest(final TransactionRequest<?> request,
+ final RequestEnvelope envelope) throws RequestException {
+ checkRequestSequence(envelope);
+
+ try {
+ final LocalHistoryIdentifier lhId = request.getTarget().getHistoryId();
+ final AbstractFrontendHistory history;
+
+ if (lhId.getHistoryId() != 0) {
+ history = localHistories.get(lhId);
+ if (history == null) {
+ LOG.debug("{}: rejecting unknown history request {}", persistenceId, request);
+ throw new UnknownHistoryException(lastSeenHistory);
+ }
+ } else {
+ history = standaloneHistory;
+ }
+
+ return history.handleTransactionRequest(request, envelope);
+ } finally {
+ expectNextRequest();
+ }
+ }
+
+ void reconnect() {
+ expectedTxSequence = 0;
+ }
+
+ void retire() {
+ // FIXME: flush all state
+ }
+
+ @Override
+ public String toString() {
+ return MoreObjects.toStringHelper(LeaderFrontendState.class).add("clientId", clientId)
+ .add("purgedHistories", purgedHistories).toString();
+ }
+}
Code Review / controller.git / blobdiff