opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/AbstractFrontendHistory.java

   1 /*
   2  * Copyright (c) 2016 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.cluster.datastore;
   9
  10 import com.google.common.base.MoreObjects;
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.collect.ImmutableMap;
  13 import com.google.common.collect.Range;
  14 import com.google.common.collect.RangeSet;
  15 import com.google.common.primitives.UnsignedLong;
  16 import java.util.HashMap;
  17 import java.util.Map;
  18 import java.util.Optional;
  19 import javax.annotation.Nullable;
  20 import org.opendaylight.controller.cluster.access.commands.AbstractReadTransactionRequest;
  21 import org.opendaylight.controller.cluster.access.commands.ClosedTransactionException;
  22 import org.opendaylight.controller.cluster.access.commands.CommitLocalTransactionRequest;
  23 import org.opendaylight.controller.cluster.access.commands.DeadTransactionException;
  24 import org.opendaylight.controller.cluster.access.commands.LocalHistorySuccess;
  25 import org.opendaylight.controller.cluster.access.commands.OutOfOrderRequestException;
  26 import org.opendaylight.controller.cluster.access.commands.TransactionPurgeRequest;
  27 import org.opendaylight.controller.cluster.access.commands.TransactionPurgeResponse;
  28 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  29 import org.opendaylight.controller.cluster.access.commands.TransactionSuccess;
  30 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
  31 import org.opendaylight.controller.cluster.access.concepts.RequestEnvelope;
  32 import org.opendaylight.controller.cluster.access.concepts.RequestException;
  33 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  34 import org.opendaylight.yangtools.concepts.Identifiable;
  35 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38
  39 /**
  40  * Abstract class for providing logical tracking of frontend local histories. This class is specialized for
  41  * standalone transactions and chained transactions.
  42  *
  43  * @author Robert Varga
  44  */
  45 abstract class AbstractFrontendHistory implements Identifiable<LocalHistoryIdentifier> {
  46     private static final Logger LOG = LoggerFactory.getLogger(AbstractFrontendHistory.class);
  47
  48     private final Map<TransactionIdentifier, FrontendTransaction> transactions = new HashMap<>();
  49     private final RangeSet<UnsignedLong> purgedTransactions;
  50     private final String persistenceId;
  51     private final ShardDataTree tree;
  52
  53     /**
  54      * Transactions closed by the previous leader. Boolean indicates whether the transaction was committed (true) or
  55      * aborted (false). We only ever shrink these.
  56      */
  57     private Map<UnsignedLong, Boolean> closedTransactions;
  58
  59     AbstractFrontendHistory(final String persistenceId, final ShardDataTree tree,
  60         final Map<UnsignedLong, Boolean> closedTransactions, final RangeSet<UnsignedLong> purgedTransactions) {
  61         this.persistenceId = Preconditions.checkNotNull(persistenceId);
  62         this.tree = Preconditions.checkNotNull(tree);
  63         this.closedTransactions = Preconditions.checkNotNull(closedTransactions);
  64         this.purgedTransactions = Preconditions.checkNotNull(purgedTransactions);
  65     }
  66
  67     final String persistenceId() {
  68         return persistenceId;
  69     }
  70
  71     final long readTime() {
  72         return tree.ticker().read();
  73     }
  74
  75     final @Nullable TransactionSuccess<?> handleTransactionRequest(final TransactionRequest<?> request,
  76             final RequestEnvelope envelope, final long now) throws RequestException {
  77         final TransactionIdentifier id = request.getTarget();
  78         final UnsignedLong ul = UnsignedLong.fromLongBits(id.getTransactionId());
  79
  80         if (request instanceof TransactionPurgeRequest) {
  81             if (purgedTransactions.contains(ul)) {
  82                 // Retransmitted purge request: nothing to do
  83                 LOG.debug("{}: transaction {} already purged", persistenceId, id);
  84                 return new TransactionPurgeResponse(id, request.getSequence());
  85             }
  86
  87             // We perform two lookups instead of a straight remove, because once the map becomes empty we switch it
  88             // to an ImmutableMap, which does not allow remove().
  89             if (closedTransactions.containsKey(ul)) {
  90                 tree.purgeTransaction(id, () -> {
  91                     closedTransactions.remove(ul);
  92                     if (closedTransactions.isEmpty()) {
  93                         closedTransactions = ImmutableMap.of();
  94                     }
  95
  96                     purgedTransactions.add(Range.singleton(ul));
  97                     LOG.debug("{}: finished purging inherited transaction {}", persistenceId(), id);
  98                     envelope.sendSuccess(new TransactionPurgeResponse(id, request.getSequence()), readTime() - now);
  99                 });
 100                 return null;
 101             }
 102
 103             final FrontendTransaction tx = transactions.get(id);
 104             if (tx == null) {
 105                 // This should never happen because the purge callback removes the transaction and puts it into
 106                 // purged transactions in one go. If it does, we warn about the situation and
 107                 LOG.warn("{}: transaction {} not tracked in {}, but not present in active transactions", persistenceId,
 108                     id, purgedTransactions);
 109                 purgedTransactions.add(Range.singleton(ul));
 110                 return new TransactionPurgeResponse(id, request.getSequence());
 111             }
 112
 113             tree.purgeTransaction(id, () -> {
 114                 purgedTransactions.add(Range.singleton(ul));
 115                 transactions.remove(id);
 116                 LOG.debug("{}: finished purging transaction {}", persistenceId(), id);
 117                 envelope.sendSuccess(new TransactionPurgeResponse(id, request.getSequence()), readTime() - now);
 118             });
 119             return null;
 120         }
 121
 122         if (purgedTransactions.contains(ul)) {
 123             LOG.warn("{}: Request {} is contained purged transactions {}", persistenceId, request, purgedTransactions);
 124             throw new DeadTransactionException(purgedTransactions);
 125         }
 126         final Boolean closed = closedTransactions.get(ul);
 127         if (closed != null) {
 128             final boolean successful = closed.booleanValue();
 129             LOG.debug("{}: Request {} refers to a {} transaction", persistenceId, request, successful ? "successful"
 130                     : "failed");
 131             throw new ClosedTransactionException(successful);
 132         }
 133
 134         FrontendTransaction tx = transactions.get(id);
 135         if (tx == null) {
 136             // The transaction does not exist and we are about to create it, check sequence number
 137             if (request.getSequence() != 0) {
 138                 LOG.debug("{}: no transaction state present, unexpected request {}", persistenceId(), request);
 139                 throw new OutOfOrderRequestException(0);
 140             }
 141
 142             tx = createTransaction(request, id);
 143             transactions.put(id, tx);
 144         } else {
 145             final Optional<TransactionSuccess<?>> maybeReplay = tx.replaySequence(request.getSequence());
 146             if (maybeReplay.isPresent()) {
 147                 final TransactionSuccess<?> replay = maybeReplay.get();
 148                 LOG.debug("{}: envelope {} replaying response {}", persistenceId(), envelope, replay);
 149                 return replay;
 150             }
 151         }
 152
 153         return tx.handleRequest(request, envelope, now);
 154     }
 155
 156     void destroy(final long sequence, final RequestEnvelope envelope, final long now) {
 157         LOG.debug("{}: closing history {}", persistenceId(), getIdentifier());
 158         tree.closeTransactionChain(getIdentifier(), () -> {
 159             envelope.sendSuccess(new LocalHistorySuccess(getIdentifier(), sequence), readTime() - now);
 160         });
 161     }
 162
 163     void purge(final long sequence, final RequestEnvelope envelope, final long now) {
 164         LOG.debug("{}: purging history {}", persistenceId(), getIdentifier());
 165         tree.purgeTransactionChain(getIdentifier(), () -> {
 166             envelope.sendSuccess(new LocalHistorySuccess(getIdentifier(), sequence), readTime() - now);
 167         });
 168     }
 169
 170     private FrontendTransaction createTransaction(final TransactionRequest<?> request, final TransactionIdentifier id)
 171             throws RequestException {
 172         if (request instanceof CommitLocalTransactionRequest) {
 173             LOG.debug("{}: allocating new ready transaction {}", persistenceId(), id);
 174             tree.getStats().incrementReadWriteTransactionCount();
 175             return createReadyTransaction(id, ((CommitLocalTransactionRequest) request).getModification());
 176         }
 177         if (request instanceof AbstractReadTransactionRequest) {
 178             if (((AbstractReadTransactionRequest<?>) request).isSnapshotOnly()) {
 179                 LOG.debug("{}: allocating new open snapshot {}", persistenceId(), id);
 180                 tree.getStats().incrementReadOnlyTransactionCount();
 181                 return createOpenSnapshot(id);
 182             }
 183         }
 184
 185         LOG.debug("{}: allocating new open transaction {}", persistenceId(), id);
 186         tree.getStats().incrementReadWriteTransactionCount();
 187         return createOpenTransaction(id);
 188     }
 189
 190     abstract FrontendTransaction createOpenSnapshot(TransactionIdentifier id) throws RequestException;
 191
 192     abstract FrontendTransaction createOpenTransaction(TransactionIdentifier id) throws RequestException;
 193
 194     abstract FrontendTransaction createReadyTransaction(TransactionIdentifier id, DataTreeModification mod)
 195         throws RequestException;
 196
 197     abstract ShardDataTreeCohort createFailedCohort(TransactionIdentifier id, DataTreeModification mod,
 198             Exception failure);
 199
 200     abstract ShardDataTreeCohort createReadyCohort(TransactionIdentifier id, DataTreeModification mod);
 201
 202     @Override
 203     public String toString() {
 204         return MoreObjects.toStringHelper(this).omitNullValues().add("identifier", getIdentifier())
 205                 .add("persistenceId", persistenceId).add("transactions", transactions).toString();
 206     }
 207 }