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.StorageLevel;
  24 import io.atomix.storage.journal.Indexed;
  25 import io.atomix.storage.journal.SegmentedJournal;
  26 import io.atomix.storage.journal.SegmentedJournalWriter;
  27 import io.atomix.utils.serializer.Namespace;
  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 Namespace DELETE_NAMESPACE = Namespace.builder().register(Long.class).build();
 151     private static final int DELETE_SEGMENT_SIZE = 64 * 1024;
 152
 153     private final String persistenceId;
 154     private final StorageLevel storage;
 155     private final int maxSegmentSize;
 156     private final int maxEntrySize;
 157     private final File directory;
 158
 159     // Tracks the time it took us to write a batch of messages
 160     private Timer batchWriteTime;
 161     // Tracks the number of individual messages written
 162     private Meter messageWriteCount;
 163     // Tracks the size distribution of messages
 164     private Histogram messageSize;
 165
 166     private DataJournal dataJournal;
 167     private SegmentedJournal<Long> deleteJournal;
 168     private long lastDelete;
 169
 170     SegmentedJournalActor(final String persistenceId, final File directory, final StorageLevel storage,
 171             final int maxEntrySize, final int maxSegmentSize) {
 172         this.persistenceId = requireNonNull(persistenceId);
 173         this.directory = requireNonNull(directory);
 174         this.storage = requireNonNull(storage);
 175         this.maxEntrySize = maxEntrySize;
 176         this.maxSegmentSize = maxSegmentSize;
 177     }
 178
 179     static Props props(final String persistenceId, final File directory, final StorageLevel storage,
 180             final int maxEntrySize, final int maxSegmentSize) {
 181         return Props.create(SegmentedJournalActor.class, requireNonNull(persistenceId), directory, storage,
 182             maxEntrySize, maxSegmentSize);
 183     }
 184
 185     @Override
 186     public Receive createReceive() {
 187         return receiveBuilder()
 188                 .match(DeleteMessagesTo.class, this::handleDeleteMessagesTo)
 189                 .match(ReadHighestSequenceNr.class, this::handleReadHighestSequenceNr)
 190                 .match(ReplayMessages.class, this::handleReplayMessages)
 191                 .match(WriteMessages.class, this::handleWriteMessages)
 192                 .matchAny(this::handleUnknown)
 193                 .build();
 194     }
 195
 196     @Override
 197     public void preStart() throws Exception {
 198         LOG.debug("{}: actor starting", persistenceId);
 199         super.preStart();
 200
 201         final MetricRegistry registry = MetricsReporter.getInstance(MeteringBehavior.DOMAIN).getMetricsRegistry();
 202         final String actorName = self().path().parent().toStringWithoutAddress() + '/' + directory.getName();
 203
 204         batchWriteTime = registry.timer(MetricRegistry.name(actorName, "batchWriteTime"));
 205         messageWriteCount = registry.meter(MetricRegistry.name(actorName, "messageWriteCount"));
 206         messageSize = registry.histogram(MetricRegistry.name(actorName, "messageSize"));
 207     }
 208
 209     @Override
 210     public void postStop() throws Exception {
 211         LOG.debug("{}: actor stopping", persistenceId);
 212         if (dataJournal != null) {
 213             dataJournal.close();
 214             LOG.debug("{}: data journal closed", persistenceId);
 215             dataJournal = null;
 216         }
 217         if (deleteJournal != null) {
 218             deleteJournal.close();
 219             LOG.debug("{}: delete journal closed", persistenceId);
 220             deleteJournal = null;
 221         }
 222         LOG.debug("{}: actor stopped", persistenceId);
 223         super.postStop();
 224     }
 225
 226     static AsyncMessage<Void> deleteMessagesTo(final long toSequenceNr) {
 227         return new DeleteMessagesTo(toSequenceNr);
 228     }
 229
 230     static AsyncMessage<Long> readHighestSequenceNr(final long fromSequenceNr) {
 231         return new ReadHighestSequenceNr(fromSequenceNr);
 232     }
 233
 234     static AsyncMessage<Void> replayMessages(final long fromSequenceNr, final long toSequenceNr, final long max,
 235             final Consumer<PersistentRepr> replayCallback) {
 236         return new ReplayMessages(fromSequenceNr, toSequenceNr, max, replayCallback);
 237     }
 238
 239     private void handleDeleteMessagesTo(final DeleteMessagesTo message) {
 240         ensureOpen();
 241
 242         LOG.debug("{}: delete messages {}", persistenceId, message);
 243         final long to = Long.min(dataJournal.lastWrittenSequenceNr(), message.toSequenceNr);
 244         LOG.debug("{}: adjusted delete to {}", persistenceId, to);
 245
 246         if (lastDelete < to) {
 247             LOG.debug("{}: deleting entries up to {}", persistenceId, to);
 248
 249             lastDelete = to;
 250             final SegmentedJournalWriter<Long> deleteWriter = deleteJournal.writer();
 251             final Indexed<Long> entry = deleteWriter.append(lastDelete);
 252             deleteWriter.commit(entry.index());
 253             dataJournal.deleteTo(lastDelete);
 254
 255             LOG.debug("{}: compaction started", persistenceId);
 256             dataJournal.compactTo(lastDelete);
 257             deleteJournal.compact(entry.index());
 258             LOG.debug("{}: compaction finished", persistenceId);
 259         } else {
 260             LOG.debug("{}: entries up to {} already deleted", persistenceId, lastDelete);
 261         }
 262
 263         message.promise.success(null);
 264     }
 265
 266     private void handleReadHighestSequenceNr(final ReadHighestSequenceNr message) {
 267         LOG.debug("{}: looking for highest sequence on {}", persistenceId, message);
 268         final Long sequence;
 269         if (directory.isDirectory()) {
 270             ensureOpen();
 271             sequence = dataJournal.lastWrittenSequenceNr();
 272         } else {
 273             sequence = 0L;
 274         }
 275
 276         LOG.debug("{}: highest sequence is {}", message, sequence);
 277         message.promise.success(sequence);
 278     }
 279
 280     private void handleReplayMessages(final ReplayMessages message) {
 281         LOG.debug("{}: replaying messages {}", persistenceId, message);
 282         ensureOpen();
 283
 284         final long from = Long.max(lastDelete + 1, message.fromSequenceNr);
 285         LOG.debug("{}: adjusted fromSequenceNr to {}", persistenceId, from);
 286
 287         dataJournal.handleReplayMessages(message, from);
 288     }
 289
 290     private void handleWriteMessages(final WriteMessages message) {
 291         ensureOpen();
 292
 293         final Stopwatch sw = Stopwatch.createStarted();
 294         final long start = dataJournal.lastWrittenSequenceNr();
 295         final long bytes = dataJournal.handleWriteMessages(message);
 296         sw.stop();
 297
 298         batchWriteTime.update(sw.elapsed(TimeUnit.NANOSECONDS), TimeUnit.NANOSECONDS);
 299         messageWriteCount.mark(dataJournal.lastWrittenSequenceNr() - start);
 300
 301         // log message after statistics are updated
 302         LOG.debug("{}: write of {} bytes completed in {}", persistenceId, bytes, sw);
 303     }
 304
 305     private void handleUnknown(final Object message) {
 306         LOG.error("{}: Received unknown message {}", persistenceId, message);
 307     }
 308
 309     private void ensureOpen() {
 310         if (dataJournal != null) {
 311             verifyNotNull(deleteJournal);
 312             return;
 313         }
 314
 315         final Stopwatch sw = Stopwatch.createStarted();
 316         deleteJournal = SegmentedJournal.<Long>builder().withDirectory(directory).withName("delete")
 317                 .withNamespace(DELETE_NAMESPACE).withMaxSegmentSize(DELETE_SEGMENT_SIZE).build();
 318         final Indexed<Long> lastEntry = deleteJournal.writer().getLastEntry();
 319         lastDelete = lastEntry == null ? 0 : lastEntry.entry();
 320
 321         dataJournal = new DataJournalV0(persistenceId, messageSize, context().system(), storage, directory,
 322             maxEntrySize, maxSegmentSize);
 323         dataJournal.deleteTo(lastDelete);
 324         LOG.debug("{}: journal open in {} with last index {}, deleted to {}", persistenceId, sw,
 325             dataJournal.lastWrittenSequenceNr(), lastDelete);
 326     }
 327 }