opendaylight/md-sal/sal-akka-segmented-journal/src/main/java/org/opendaylight/controller/akka/segjournal/SegmentedJournalActor.java

   1 /*
   2  * Copyright (c) 2019 Pantheon Technologies, s.r.o. 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.akka.segjournal;
   9
  10 import static com.google.common.base.Verify.verifyNotNull;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import akka.actor.AbstractActor;
  14 import akka.actor.Props;
  15 import akka.persistence.AtomicWrite;
  16 import akka.persistence.PersistentRepr;
  17 import com.codahale.metrics.Histogram;
  18 import com.codahale.metrics.Meter;
  19 import com.codahale.metrics.MetricRegistry;
  20 import com.codahale.metrics.Timer;
  21 import com.google.common.base.MoreObjects;
  22 import io.atomix.storage.StorageLevel;
  23 import io.atomix.storage.journal.Indexed;
  24 import io.atomix.storage.journal.SegmentedJournal;
  25 import io.atomix.storage.journal.SegmentedJournalWriter;
  26 import io.atomix.utils.serializer.Namespace;
  27 import java.io.File;
  28 import java.util.ArrayList;
  29 import java.util.List;
  30 import java.util.Optional;
  31 import java.util.concurrent.TimeUnit;
  32 import java.util.function.Consumer;
  33 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  34 import org.opendaylight.controller.cluster.reporting.MetricsReporter;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37 import scala.concurrent.Future;
  38 import scala.concurrent.Promise;
  39
  40 /**
  41  * This actor handles a single PersistentActor's journal. The journal is split into two {@link SegmentedJournal}s:
  42  * <ul>
  43  *     <li>A memory-mapped data journal, containing actual data entries</li>
  44  *     <li>A simple file journal, containing sequence numbers of last deleted entry</li>
  45  * </ul>
  46  *
  47  * <p>
  48  * This is a conscious design decision to minimize the amount of data that is being stored in the data journal while
  49  * speeding up normal operations. Since the SegmentedJournal is an append-only linear log and Akka requires the ability
  50  * to delete persistence entries, we need ability to mark a subset of a SegmentedJournal as deleted. While we could
  51  * treat such delete requests as normal events, this leads to a mismatch between SegmentedJournal indices (as exposed by
  52  * {@link Indexed}) and Akka sequence numbers -- requiring us to potentially perform costly deserialization to find the
  53  * index corresponding to a particular sequence number, or maintain moderately-complex logic and data structures to
  54  * perform that mapping in sub-linear time complexity.
  55  *
  56  * <p>
  57  * Split-file approach allows us to treat sequence numbers and indices as equivalent, without maintaining any explicit
  58  * mapping information. The only additional information we need to maintain is the last deleted sequence number.
  59  *
  60  * @author Robert Varga
  61  */
  62 final class SegmentedJournalActor extends AbstractActor {
  63     abstract static class AsyncMessage<T> {
  64         final Promise<T> promise = Promise.apply();
  65     }
  66
  67     private static final class ReadHighestSequenceNr extends AsyncMessage<Long> {
  68         private final long fromSequenceNr;
  69
  70         ReadHighestSequenceNr(final long fromSequenceNr) {
  71             this.fromSequenceNr = fromSequenceNr;
  72         }
  73
  74         @Override
  75         public String toString() {
  76             return MoreObjects.toStringHelper(this).add("fromSequenceNr", fromSequenceNr).toString();
  77         }
  78     }
  79
  80     static final class ReplayMessages extends AsyncMessage<Void> {
  81         private final long fromSequenceNr;
  82         final long toSequenceNr;
  83         final long max;
  84         final Consumer<PersistentRepr> replayCallback;
  85
  86         ReplayMessages(final long fromSequenceNr,
  87                 final long toSequenceNr, final long max, final Consumer<PersistentRepr> replayCallback) {
  88             this.fromSequenceNr = fromSequenceNr;
  89             this.toSequenceNr = toSequenceNr;
  90             this.max = max;
  91             this.replayCallback = requireNonNull(replayCallback);
  92         }
  93
  94         @Override
  95         public String toString() {
  96             return MoreObjects.toStringHelper(this).add("fromSequenceNr", fromSequenceNr)
  97                     .add("toSequenceNr", toSequenceNr).add("max", max).toString();
  98         }
  99     }
 100
 101     static final class WriteMessages {
 102         private final List<AtomicWrite> requests = new ArrayList<>();
 103         private final List<Promise<Optional<Exception>>> results = new ArrayList<>();
 104
 105         Future<Optional<Exception>> add(final AtomicWrite write) {
 106             final Promise<Optional<Exception>> promise = Promise.apply();
 107             requests.add(write);
 108             results.add(promise);
 109             return promise.future();
 110         }
 111
 112         int size() {
 113             return requests.size();
 114         }
 115
 116         AtomicWrite getRequest(final int index) {
 117             return requests.get(index);
 118         }
 119
 120         void setFailure(final int index, final Exception cause) {
 121             results.get(index).success(Optional.of(cause));
 122
 123         }
 124
 125         void setSuccess(final int index) {
 126             results.get(index).success(Optional.empty());
 127         }
 128
 129         @Override
 130         public String toString() {
 131             return MoreObjects.toStringHelper(this).add("requests", requests).toString();
 132         }
 133     }
 134
 135     private static final class DeleteMessagesTo extends AsyncMessage<Void> {
 136         final long toSequenceNr;
 137
 138         DeleteMessagesTo(final long toSequenceNr) {
 139             this.toSequenceNr = toSequenceNr;
 140         }
 141
 142         @Override
 143         public String toString() {
 144             return MoreObjects.toStringHelper(this).add("toSequenceNr", toSequenceNr).toString();
 145         }
 146     }
 147
 148     private static final Logger LOG = LoggerFactory.getLogger(SegmentedJournalActor.class);
 149     private static final Namespace DELETE_NAMESPACE = Namespace.builder().register(Long.class).build();
 150     private static final int DELETE_SEGMENT_SIZE = 64 * 1024;
 151
 152     private final String persistenceId;
 153     private final StorageLevel storage;
 154     private final int maxSegmentSize;
 155     private final int maxEntrySize;
 156     private final File directory;
 157
 158     // Tracks the time it took us to write a batch of messages
 159     private Timer batchWriteTime;
 160     // Tracks the number of individual messages written
 161     private Meter messageWriteCount;
 162     // Tracks the size distribution of messages
 163     private Histogram messageSize;
 164
 165     private DataJournal dataJournal;
 166     private SegmentedJournal<Long> deleteJournal;
 167     private long lastDelete;
 168
 169     SegmentedJournalActor(final String persistenceId, final File directory, final StorageLevel storage,
 170             final int maxEntrySize, final int maxSegmentSize) {
 171         this.persistenceId = requireNonNull(persistenceId);
 172         this.directory = requireNonNull(directory);
 173         this.storage = requireNonNull(storage);
 174         this.maxEntrySize = maxEntrySize;
 175         this.maxSegmentSize = maxSegmentSize;
 176     }
 177
 178     static Props props(final String persistenceId, final File directory, final StorageLevel storage,
 179             final int maxEntrySize, final int maxSegmentSize) {
 180         return Props.create(SegmentedJournalActor.class, requireNonNull(persistenceId), directory, storage,
 181             maxEntrySize, maxSegmentSize);
 182     }
 183
 184     @Override
 185     public Receive createReceive() {
 186         return receiveBuilder()
 187                 .match(DeleteMessagesTo.class, this::handleDeleteMessagesTo)
 188                 .match(ReadHighestSequenceNr.class, this::handleReadHighestSequenceNr)
 189                 .match(ReplayMessages.class, this::handleReplayMessages)
 190                 .match(WriteMessages.class, this::handleWriteMessages)
 191                 .matchAny(this::handleUnknown)
 192                 .build();
 193     }
 194
 195     @Override
 196     public void preStart() throws Exception {
 197         LOG.debug("{}: actor starting", persistenceId);
 198         super.preStart();
 199
 200         final MetricRegistry registry = MetricsReporter.getInstance(MeteringBehavior.DOMAIN).getMetricsRegistry();
 201         final String actorName = self().path().parent().toStringWithoutAddress() + '/' + directory.getName();
 202
 203         batchWriteTime = registry.timer(MetricRegistry.name(actorName, "batchWriteTime"));
 204         messageWriteCount = registry.meter(MetricRegistry.name(actorName, "messageWriteCount"));
 205         messageSize = registry.histogram(MetricRegistry.name(actorName, "messageSize"));
 206     }
 207
 208     @Override
 209     public void postStop() throws Exception {
 210         LOG.debug("{}: actor stopping", persistenceId);
 211         if (dataJournal != null) {
 212             dataJournal.close();
 213             LOG.debug("{}: data journal closed", persistenceId);
 214             dataJournal = null;
 215         }
 216         if (deleteJournal != null) {
 217             deleteJournal.close();
 218             LOG.debug("{}: delete journal closed", persistenceId);
 219             deleteJournal = null;
 220         }
 221         LOG.debug("{}: actor stopped", persistenceId);
 222         super.postStop();
 223     }
 224
 225     static AsyncMessage<Void> deleteMessagesTo(final long toSequenceNr) {
 226         return new DeleteMessagesTo(toSequenceNr);
 227     }
 228
 229     static AsyncMessage<Long> readHighestSequenceNr(final long fromSequenceNr) {
 230         return new ReadHighestSequenceNr(fromSequenceNr);
 231     }
 232
 233     static AsyncMessage<Void> replayMessages(final long fromSequenceNr, final long toSequenceNr, final long max,
 234             final Consumer<PersistentRepr> replayCallback) {
 235         return new ReplayMessages(fromSequenceNr, toSequenceNr, max, replayCallback);
 236     }
 237
 238     private void handleDeleteMessagesTo(final DeleteMessagesTo message) {
 239         ensureOpen();
 240
 241         LOG.debug("{}: delete messages {}", persistenceId, message);
 242         final long to = Long.min(dataJournal.lastWrittenSequenceNr(), message.toSequenceNr);
 243         LOG.debug("{}: adjusted delete to {}", persistenceId, to);
 244
 245         if (lastDelete < to) {
 246             LOG.debug("{}: deleting entries up to {}", persistenceId, to);
 247
 248             lastDelete = to;
 249             final SegmentedJournalWriter<Long> deleteWriter = deleteJournal.writer();
 250             final Indexed<Long> entry = deleteWriter.append(lastDelete);
 251             deleteWriter.commit(entry.index());
 252             dataJournal.deleteTo(lastDelete);
 253
 254             LOG.debug("{}: compaction started", persistenceId);
 255             dataJournal.compactTo(lastDelete);
 256             deleteJournal.compact(entry.index());
 257             LOG.debug("{}: compaction finished", persistenceId);
 258         } else {
 259             LOG.debug("{}: entries up to {} already deleted", persistenceId, lastDelete);
 260         }
 261
 262         message.promise.success(null);
 263     }
 264
 265     private void handleReadHighestSequenceNr(final ReadHighestSequenceNr message) {
 266         LOG.debug("{}: looking for highest sequence on {}", persistenceId, message);
 267         final Long sequence;
 268         if (directory.isDirectory()) {
 269             ensureOpen();
 270             sequence = dataJournal.lastWrittenSequenceNr();
 271         } else {
 272             sequence = 0L;
 273         }
 274
 275         LOG.debug("{}: highest sequence is {}", message, sequence);
 276         message.promise.success(sequence);
 277     }
 278
 279     private void handleReplayMessages(final ReplayMessages message) {
 280         LOG.debug("{}: replaying messages {}", persistenceId, message);
 281         ensureOpen();
 282
 283         final long from = Long.max(lastDelete + 1, message.fromSequenceNr);
 284         LOG.debug("{}: adjusted fromSequenceNr to {}", persistenceId, from);
 285
 286         dataJournal.handleReplayMessages(message, from);
 287     }
 288
 289     private void handleWriteMessages(final WriteMessages message) {
 290         ensureOpen();
 291
 292         final long startTicks = System.nanoTime();
 293         final long start = dataJournal.lastWrittenSequenceNr();
 294
 295         dataJournal.handleWriteMessages(message);
 296
 297         batchWriteTime.update(System.nanoTime() - startTicks, TimeUnit.NANOSECONDS);
 298         messageWriteCount.mark(dataJournal.lastWrittenSequenceNr() - start);
 299     }
 300
 301     private void handleUnknown(final Object message) {
 302         LOG.error("{}: Received unknown message {}", persistenceId, message);
 303     }
 304
 305     private void ensureOpen() {
 306         if (dataJournal != null) {
 307             verifyNotNull(deleteJournal);
 308             return;
 309         }
 310
 311         deleteJournal = SegmentedJournal.<Long>builder().withDirectory(directory).withName("delete")
 312                 .withNamespace(DELETE_NAMESPACE).withMaxSegmentSize(DELETE_SEGMENT_SIZE).build();
 313         final Indexed<Long> lastEntry = deleteJournal.writer().getLastEntry();
 314         lastDelete = lastEntry == null ? 0 : lastEntry.entry();
 315
 316         dataJournal = new DataJournalV0(persistenceId, messageSize, context().system(), storage, directory,
 317             maxEntrySize, maxSegmentSize);
 318         dataJournal.deleteTo(lastDelete);
 319         LOG.debug("{}: journal open with last index {}, deleted to {}", persistenceId,
 320             dataJournal.lastWrittenSequenceNr(), lastDelete);
 321     }
 322 }