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 com.google.common.base.Stopwatch;
  23 import io.atomix.storage.journal.Indexed;
  24 import io.atomix.storage.journal.JournalSerdes;
  25 import io.atomix.storage.journal.SegmentedJournal;
  26 import io.atomix.storage.journal.SegmentedJournalWriter;
  27 import io.atomix.storage.journal.StorageLevel;
  28 import java.io.File;
  29 import java.util.ArrayList;
  30 import java.util.List;
  31 import java.util.Optional;
  32 import java.util.concurrent.TimeUnit;
  33 import java.util.function.Consumer;
  34 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  35 import org.opendaylight.controller.cluster.reporting.MetricsReporter;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38 import scala.concurrent.Future;
  39 import scala.concurrent.Promise;
  40
  41 /**
  42  * This actor handles a single PersistentActor's journal. The journal is split into two {@link SegmentedJournal}s:
  43  * <ul>
  44  *     <li>A memory-mapped data journal, containing actual data entries</li>
  45  *     <li>A simple file journal, containing sequence numbers of last deleted entry</li>
  46  * </ul>
  47  *
  48  * <p>
  49  * This is a conscious design decision to minimize the amount of data that is being stored in the data journal while
  50  * speeding up normal operations. Since the SegmentedJournal is an append-only linear log and Akka requires the ability
  51  * to delete persistence entries, we need ability to mark a subset of a SegmentedJournal as deleted. While we could
  52  * treat such delete requests as normal events, this leads to a mismatch between SegmentedJournal indices (as exposed by
  53  * {@link Indexed}) and Akka sequence numbers -- requiring us to potentially perform costly deserialization to find the
  54  * index corresponding to a particular sequence number, or maintain moderately-complex logic and data structures to
  55  * perform that mapping in sub-linear time complexity.
  56  *
  57  * <p>
  58  * Split-file approach allows us to treat sequence numbers and indices as equivalent, without maintaining any explicit
  59  * mapping information. The only additional information we need to maintain is the last deleted sequence number.
  60  *
  61  * @author Robert Varga
  62  */
  63 final class SegmentedJournalActor extends AbstractActor {
  64     abstract static class AsyncMessage<T> {
  65         final Promise<T> promise = Promise.apply();
  66     }
  67
  68     private static final class ReadHighestSequenceNr extends AsyncMessage<Long> {
  69         private final long fromSequenceNr;
  70
  71         ReadHighestSequenceNr(final long fromSequenceNr) {
  72             this.fromSequenceNr = fromSequenceNr;
  73         }
  74
  75         @Override
  76         public String toString() {
  77             return MoreObjects.toStringHelper(this).add("fromSequenceNr", fromSequenceNr).toString();
  78         }
  79     }
  80
  81     static final class ReplayMessages extends AsyncMessage<Void> {
  82         private final long fromSequenceNr;
  83         final long toSequenceNr;
  84         final long max;
  85         final Consumer<PersistentRepr> replayCallback;
  86
  87         ReplayMessages(final long fromSequenceNr,
  88                 final long toSequenceNr, final long max, final Consumer<PersistentRepr> replayCallback) {
  89             this.fromSequenceNr = fromSequenceNr;
  90             this.toSequenceNr = toSequenceNr;
  91             this.max = max;
  92             this.replayCallback = requireNonNull(replayCallback);
  93         }
  94
  95         @Override
  96         public String toString() {
  97             return MoreObjects.toStringHelper(this).add("fromSequenceNr", fromSequenceNr)
  98                     .add("toSequenceNr", toSequenceNr).add("max", max).toString();
  99         }
 100     }
 101
 102     static final class WriteMessages {
 103         private final List<AtomicWrite> requests = new ArrayList<>();
 104         private final List<Promise<Optional<Exception>>> results = new ArrayList<>();
 105
 106         Future<Optional<Exception>> add(final AtomicWrite write) {
 107             final Promise<Optional<Exception>> promise = Promise.apply();
 108             requests.add(write);
 109             results.add(promise);
 110             return promise.future();
 111         }
 112
 113         int size() {
 114             return requests.size();
 115         }
 116
 117         AtomicWrite getRequest(final int index) {
 118             return requests.get(index);
 119         }
 120
 121         void setFailure(final int index, final Exception cause) {
 122             results.get(index).success(Optional.of(cause));
 123
 124         }
 125
 126         void setSuccess(final int index) {
 127             results.get(index).success(Optional.empty());
 128         }
 129
 130         @Override
 131         public String toString() {
 132             return MoreObjects.toStringHelper(this).add("requests", requests).toString();
 133         }
 134     }
 135
 136     private static final class DeleteMessagesTo extends AsyncMessage<Void> {
 137         final long toSequenceNr;
 138
 139         DeleteMessagesTo(final long toSequenceNr) {
 140             this.toSequenceNr = toSequenceNr;
 141         }
 142
 143         @Override
 144         public String toString() {
 145             return MoreObjects.toStringHelper(this).add("toSequenceNr", toSequenceNr).toString();
 146         }
 147     }
 148
 149     private static final Logger LOG = LoggerFactory.getLogger(SegmentedJournalActor.class);
 150     private static final JournalSerdes DELETE_NAMESPACE = JournalSerdes.builder()
 151         .register(new LongSerdes(), Long.class)
 152         .build();
 153     private static final int DELETE_SEGMENT_SIZE = 64 * 1024;
 154
 155     private final String persistenceId;
 156     private final StorageLevel storage;
 157     private final int maxSegmentSize;
 158     private final int maxEntrySize;
 159     private final File directory;
 160
 161     // Tracks the time it took us to write a batch of messages
 162     private Timer batchWriteTime;
 163     // Tracks the number of individual messages written
 164     private Meter messageWriteCount;
 165     // Tracks the size distribution of messages
 166     private Histogram messageSize;
 167
 168     private DataJournal dataJournal;
 169     private SegmentedJournal<Long> deleteJournal;
 170     private long lastDelete;
 171
 172     SegmentedJournalActor(final String persistenceId, final File directory, final StorageLevel storage,
 173             final int maxEntrySize, final int maxSegmentSize) {
 174         this.persistenceId = requireNonNull(persistenceId);
 175         this.directory = requireNonNull(directory);
 176         this.storage = requireNonNull(storage);
 177         this.maxEntrySize = maxEntrySize;
 178         this.maxSegmentSize = maxSegmentSize;
 179     }
 180
 181     static Props props(final String persistenceId, final File directory, final StorageLevel storage,
 182             final int maxEntrySize, final int maxSegmentSize) {
 183         return Props.create(SegmentedJournalActor.class, requireNonNull(persistenceId), directory, storage,
 184             maxEntrySize, maxSegmentSize);
 185     }
 186
 187     @Override
 188     public Receive createReceive() {
 189         return receiveBuilder()
 190                 .match(DeleteMessagesTo.class, this::handleDeleteMessagesTo)
 191                 .match(ReadHighestSequenceNr.class, this::handleReadHighestSequenceNr)
 192                 .match(ReplayMessages.class, this::handleReplayMessages)
 193                 .match(WriteMessages.class, this::handleWriteMessages)
 194                 .matchAny(this::handleUnknown)
 195                 .build();
 196     }
 197
 198     @Override
 199     public void preStart() throws Exception {
 200         LOG.debug("{}: actor starting", persistenceId);
 201         super.preStart();
 202
 203         final MetricRegistry registry = MetricsReporter.getInstance(MeteringBehavior.DOMAIN).getMetricsRegistry();
 204         final String actorName = self().path().parent().toStringWithoutAddress() + '/' + directory.getName();
 205
 206         batchWriteTime = registry.timer(MetricRegistry.name(actorName, "batchWriteTime"));
 207         messageWriteCount = registry.meter(MetricRegistry.name(actorName, "messageWriteCount"));
 208         messageSize = registry.histogram(MetricRegistry.name(actorName, "messageSize"));
 209     }
 210
 211     @Override
 212     public void postStop() throws Exception {
 213         LOG.debug("{}: actor stopping", persistenceId);
 214         if (dataJournal != null) {
 215             dataJournal.close();
 216             LOG.debug("{}: data journal closed", persistenceId);
 217             dataJournal = null;
 218         }
 219         if (deleteJournal != null) {
 220             deleteJournal.close();
 221             LOG.debug("{}: delete journal closed", persistenceId);
 222             deleteJournal = null;
 223         }
 224         LOG.debug("{}: actor stopped", persistenceId);
 225         super.postStop();
 226     }
 227
 228     static AsyncMessage<Void> deleteMessagesTo(final long toSequenceNr) {
 229         return new DeleteMessagesTo(toSequenceNr);
 230     }
 231
 232     static AsyncMessage<Long> readHighestSequenceNr(final long fromSequenceNr) {
 233         return new ReadHighestSequenceNr(fromSequenceNr);
 234     }
 235
 236     static AsyncMessage<Void> replayMessages(final long fromSequenceNr, final long toSequenceNr, final long max,
 237             final Consumer<PersistentRepr> replayCallback) {
 238         return new ReplayMessages(fromSequenceNr, toSequenceNr, max, replayCallback);
 239     }
 240
 241     private void handleDeleteMessagesTo(final DeleteMessagesTo message) {
 242         ensureOpen();
 243
 244         LOG.debug("{}: delete messages {}", persistenceId, message);
 245         final long to = Long.min(dataJournal.lastWrittenSequenceNr(), message.toSequenceNr);
 246         LOG.debug("{}: adjusted delete to {}", persistenceId, to);
 247
 248         if (lastDelete < to) {
 249             LOG.debug("{}: deleting entries up to {}", persistenceId, to);
 250
 251             lastDelete = to;
 252             final SegmentedJournalWriter<Long> deleteWriter = deleteJournal.writer();
 253             final Indexed<Long> entry = deleteWriter.append(lastDelete);
 254             deleteWriter.commit(entry.index());
 255             dataJournal.deleteTo(lastDelete);
 256
 257             LOG.debug("{}: compaction started", persistenceId);
 258             dataJournal.compactTo(lastDelete);
 259             deleteJournal.compact(entry.index());
 260             LOG.debug("{}: compaction finished", persistenceId);
 261         } else {
 262             LOG.debug("{}: entries up to {} already deleted", persistenceId, lastDelete);
 263         }
 264
 265         message.promise.success(null);
 266     }
 267
 268     private void handleReadHighestSequenceNr(final ReadHighestSequenceNr message) {
 269         LOG.debug("{}: looking for highest sequence on {}", persistenceId, message);
 270         final Long sequence;
 271         if (directory.isDirectory()) {
 272             ensureOpen();
 273             sequence = dataJournal.lastWrittenSequenceNr();
 274         } else {
 275             sequence = 0L;
 276         }
 277
 278         LOG.debug("{}: highest sequence is {}", message, sequence);
 279         message.promise.success(sequence);
 280     }
 281
 282     private void handleReplayMessages(final ReplayMessages message) {
 283         LOG.debug("{}: replaying messages {}", persistenceId, message);
 284         ensureOpen();
 285
 286         final long from = Long.max(lastDelete + 1, message.fromSequenceNr);
 287         LOG.debug("{}: adjusted fromSequenceNr to {}", persistenceId, from);
 288
 289         dataJournal.handleReplayMessages(message, from);
 290     }
 291
 292     private void handleWriteMessages(final WriteMessages message) {
 293         ensureOpen();
 294
 295         final Stopwatch sw = Stopwatch.createStarted();
 296         final long start = dataJournal.lastWrittenSequenceNr();
 297         final long bytes = dataJournal.handleWriteMessages(message);
 298         sw.stop();
 299
 300         batchWriteTime.update(sw.elapsed(TimeUnit.NANOSECONDS), TimeUnit.NANOSECONDS);
 301         messageWriteCount.mark(dataJournal.lastWrittenSequenceNr() - start);
 302
 303         // log message after statistics are updated
 304         LOG.debug("{}: write of {} bytes completed in {}", persistenceId, bytes, sw);
 305     }
 306
 307     private void handleUnknown(final Object message) {
 308         LOG.error("{}: Received unknown message {}", persistenceId, message);
 309     }
 310
 311     private void ensureOpen() {
 312         if (dataJournal != null) {
 313             verifyNotNull(deleteJournal);
 314             return;
 315         }
 316
 317         final Stopwatch sw = Stopwatch.createStarted();
 318         deleteJournal = SegmentedJournal.<Long>builder().withDirectory(directory).withName("delete")
 319                 .withNamespace(DELETE_NAMESPACE).withMaxSegmentSize(DELETE_SEGMENT_SIZE).build();
 320         final Indexed<Long> lastEntry = deleteJournal.writer().getLastEntry();
 321         lastDelete = lastEntry == null ? 0 : lastEntry.entry();
 322
 323         dataJournal = new DataJournalV0(persistenceId, messageSize, context().system(), storage, directory,
 324             maxEntrySize, maxSegmentSize);
 325         dataJournal.deleteTo(lastDelete);
 326         LOG.debug("{}: journal open in {} with last index {}, deleted to {}", persistenceId, sw,
 327             dataJournal.lastWrittenSequenceNr(), lastDelete);
 328     }
 329 }