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.IncrementTransactionSequenceRequest;
  25 import org.opendaylight.controller.cluster.access.commands.LocalHistorySuccess;
  26 import org.opendaylight.controller.cluster.access.commands.OutOfOrderRequestException;
  27 import org.opendaylight.controller.cluster.access.commands.TransactionPurgeRequest;
  28 import org.opendaylight.controller.cluster.access.commands.TransactionPurgeResponse;
  29 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  30 import org.opendaylight.controller.cluster.access.commands.TransactionSuccess;
  31 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
  32 import org.opendaylight.controller.cluster.access.concepts.RequestEnvelope;
  33 import org.opendaylight.controller.cluster.access.concepts.RequestException;
  34 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  35 import org.opendaylight.yangtools.concepts.Identifiable;
  36 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  37 import org.slf4j.Logger;
  38 import org.slf4j.LoggerFactory;
  39
  40 /**
  41  * Abstract class for providing logical tracking of frontend local histories. This class is specialized for
  42  * standalone transactions and chained transactions.
  43  *
  44  * @author Robert Varga
  45  */
  46 abstract class AbstractFrontendHistory implements Identifiable<LocalHistoryIdentifier> {
  47     private static final Logger LOG = LoggerFactory.getLogger(AbstractFrontendHistory.class);
  48
  49     private final Map<TransactionIdentifier, FrontendTransaction> transactions = new HashMap<>();
  50     private final RangeSet<UnsignedLong> purgedTransactions;
  51     private final String persistenceId;
  52     private final ShardDataTree tree;
  53
  54     /**
  55      * Transactions closed by the previous leader. Boolean indicates whether the transaction was committed (true) or
  56      * aborted (false). We only ever shrink these.
  57      */
  58     private Map<UnsignedLong, Boolean> closedTransactions;
  59
  60     AbstractFrontendHistory(final String persistenceId, final ShardDataTree tree,
  61         final Map<UnsignedLong, Boolean> closedTransactions, final RangeSet<UnsignedLong> purgedTransactions) {
  62         this.persistenceId = Preconditions.checkNotNull(persistenceId);
  63         this.tree = Preconditions.checkNotNull(tree);
  64         this.closedTransactions = Preconditions.checkNotNull(closedTransactions);
  65         this.purgedTransactions = Preconditions.checkNotNull(purgedTransactions);
  66     }
  67
  68     final String persistenceId() {
  69         return persistenceId;
  70     }
  71
  72     final long readTime() {
  73         return tree.ticker().read();
  74     }
  75
  76     final @Nullable TransactionSuccess<?> handleTransactionRequest(final TransactionRequest<?> request,
  77             final RequestEnvelope envelope, final long now) throws RequestException {
  78         final TransactionIdentifier id = request.getTarget();
  79         final UnsignedLong ul = UnsignedLong.fromLongBits(id.getTransactionId());
  80
  81         if (request instanceof TransactionPurgeRequest) {
  82             if (purgedTransactions.contains(ul)) {
  83                 // Retransmitted purge request: nothing to do
  84                 LOG.debug("{}: transaction {} already purged", persistenceId, id);
  85                 return new TransactionPurgeResponse(id, request.getSequence());
  86             }
  87
  88             // We perform two lookups instead of a straight remove, because once the map becomes empty we switch it
  89             // to an ImmutableMap, which does not allow remove().
  90             if (closedTransactions.containsKey(ul)) {
  91                 tree.purgeTransaction(id, () -> {
  92                     closedTransactions.remove(ul);
  93                     if (closedTransactions.isEmpty()) {
  94                         closedTransactions = ImmutableMap.of();
  95                     }
  96
  97                     purgedTransactions.add(Range.singleton(ul));
  98                     LOG.debug("{}: finished purging inherited transaction {}", persistenceId(), id);
  99                     envelope.sendSuccess(new TransactionPurgeResponse(id, request.getSequence()), readTime() - now);
 100                 });
 101                 return null;
 102             }
 103
 104             final FrontendTransaction tx = transactions.get(id);
 105             if (tx == null) {
 106                 // This should never happen because the purge callback removes the transaction and puts it into
 107                 // purged transactions in one go. If it does, we warn about the situation and
 108                 LOG.warn("{}: transaction {} not tracked in {}, but not present in active transactions", persistenceId,
 109                     id, purgedTransactions);
 110                 purgedTransactions.add(Range.singleton(ul));
 111                 return new TransactionPurgeResponse(id, request.getSequence());
 112             }
 113
 114             tree.purgeTransaction(id, () -> {
 115                 purgedTransactions.add(Range.singleton(ul));
 116                 transactions.remove(id);
 117                 LOG.debug("{}: finished purging transaction {}", persistenceId(), id);
 118                 envelope.sendSuccess(new TransactionPurgeResponse(id, request.getSequence()), readTime() - now);
 119             });
 120             return null;
 121         }
 122
 123         if (purgedTransactions.contains(ul)) {
 124             LOG.warn("{}: Request {} is contained purged transactions {}", persistenceId, request, purgedTransactions);
 125             throw new DeadTransactionException(purgedTransactions);
 126         }
 127         final Boolean closed = closedTransactions.get(ul);
 128         if (closed != null) {
 129             final boolean successful = closed.booleanValue();
 130             LOG.debug("{}: Request {} refers to a {} transaction", persistenceId, request, successful ? "successful"
 131                     : "failed");
 132             throw new ClosedTransactionException(successful);
 133         }
 134
 135         FrontendTransaction tx = transactions.get(id);
 136         if (tx == null) {
 137             // The transaction does not exist and we are about to create it, check sequence number
 138             if (request.getSequence() != 0) {
 139                 LOG.warn("{}: no transaction state present, unexpected request {}", persistenceId(), request);
 140                 throw new OutOfOrderRequestException(0);
 141             }
 142
 143             tx = createTransaction(request, id);
 144             transactions.put(id, tx);
 145         } else if (!(request instanceof IncrementTransactionSequenceRequest)) {
 146             final Optional<TransactionSuccess<?>> maybeReplay = tx.replaySequence(request.getSequence());
 147             if (maybeReplay.isPresent()) {
 148                 final TransactionSuccess<?> replay = maybeReplay.get();
 149                 LOG.debug("{}: envelope {} replaying response {}", persistenceId(), envelope, replay);
 150                 return replay;
 151             }
 152         }
 153
 154         return tx.handleRequest(request, envelope, now);
 155     }
 156
 157     void destroy(final long sequence, final RequestEnvelope envelope, final long now) {
 158         LOG.debug("{}: closing history {}", persistenceId(), getIdentifier());
 159         tree.closeTransactionChain(getIdentifier(), () -> {
 160             envelope.sendSuccess(new LocalHistorySuccess(getIdentifier(), sequence), readTime() - now);
 161         });
 162     }
 163
 164     void purge(final long sequence, final RequestEnvelope envelope, final long now) {
 165         LOG.debug("{}: purging history {}", persistenceId(), getIdentifier());
 166         tree.purgeTransactionChain(getIdentifier(), () -> {
 167             envelope.sendSuccess(new LocalHistorySuccess(getIdentifier(), sequence), readTime() - now);
 168         });
 169     }
 170
 171     private FrontendTransaction createTransaction(final TransactionRequest<?> request, final TransactionIdentifier id)
 172             throws RequestException {
 173         if (request instanceof CommitLocalTransactionRequest) {
 174             LOG.debug("{}: allocating new ready transaction {}", persistenceId(), id);
 175             tree.getStats().incrementReadWriteTransactionCount();
 176             return createReadyTransaction(id, ((CommitLocalTransactionRequest) request).getModification());
 177         }
 178         if (request instanceof AbstractReadTransactionRequest) {
 179             if (((AbstractReadTransactionRequest<?>) request).isSnapshotOnly()) {
 180                 LOG.debug("{}: allocating new open snapshot {}", persistenceId(), id);
 181                 tree.getStats().incrementReadOnlyTransactionCount();
 182                 return createOpenSnapshot(id);
 183             }
 184         }
 185
 186         LOG.debug("{}: allocating new open transaction {}", persistenceId(), id);
 187         tree.getStats().incrementReadWriteTransactionCount();
 188         return createOpenTransaction(id);
 189     }
 190
 191     abstract FrontendTransaction createOpenSnapshot(TransactionIdentifier id) throws RequestException;
 192
 193     abstract FrontendTransaction createOpenTransaction(TransactionIdentifier id) throws RequestException;
 194
 195     abstract FrontendTransaction createReadyTransaction(TransactionIdentifier id, DataTreeModification mod)
 196         throws RequestException;
 197
 198     abstract ShardDataTreeCohort createFailedCohort(TransactionIdentifier id, DataTreeModification mod,
 199             Exception failure);
 200
 201     abstract ShardDataTreeCohort createReadyCohort(TransactionIdentifier id, DataTreeModification mod);
 202
 203     @Override
 204     public String toString() {
 205         return MoreObjects.toStringHelper(this).omitNullValues().add("identifier", getIdentifier())
 206                 .add("persistenceId", persistenceId).add("transactions", transactions).toString();
 207     }
 208 }