Skip to content

Commit

Permalink
feat: consensus can use birth rounds to determine ancient status (#17907
Browse files Browse the repository at this point in the history 
)

Signed-off-by: Lazar Petrovic <[email protected]>
Signed-off-by: Timo Brandstätter <[email protected]>
Co-authored-by: Timo Brandstätter <[email protected]>
  • Loading branch information
@lpetrovic05 @timo0
lpetrovic05 and timo0 authored Feb 21, 2025
1 parent 007b529 commit acd08f7
Show file tree
Hide file tree
Showing 42 changed files with 624 additions and 699 deletions.
40 changes: 19 additions & 21 deletions platform-sdk/swirlds-platform-core/src/main/java/com/swirlds/platform/ConsensusImpl.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,7 @@
import com.swirlds.platform.internal.EventImpl;
import com.swirlds.platform.metrics.ConsensusMetrics;
import com.swirlds.platform.roster.RosterUtils;
import com.swirlds.platform.system.events.EventConstants;
import com.swirlds.platform.util.MarkerFileWriter;
import edu.umd.cs.findbugs.annotations.NonNull;
import edu.umd.cs.findbugs.annotations.Nullable;
Expand Down Expand Up @@ -221,11 +222,12 @@ public ConsensusImpl(
this.rosterTotalWeight = RosterUtils.computeTotalWeight(roster);
this.rosterIndicesMap = RosterUtils.toIndicesMap(roster);

this.rounds = new ConsensusRounds(config, roster);
this.ancientMode = platformContext
.getConfiguration()
.getConfigData(EventConfig.class)
.getAncientMode();
this.rounds = new ConsensusRounds(config, ancientMode, roster);

this.noSuperMajorityLogger = new RateLimitedLogger(logger, platformContext.getTime(), Duration.ofMinutes(1));
this.noJudgeLogger = new RateLimitedLogger(logger, platformContext.getTime(), Duration.ofMinutes(1));
this.coinRoundLogger = new RateLimitedLogger(logger, platformContext.getTime(), Duration.ofMinutes(1));
Expand Down Expand Up @@ -345,7 +347,7 @@ && round(insertedEvent.getOtherParent()) == ConsensusConstants.ROUND_NEGATIVE_IN
continue;
}

if (insertedEvent.isConsensus() || rounds.isAncient(insertedEvent)) {
if (insertedEvent.isConsensus() || ancient(insertedEvent)) {
insertedEvent.clearMetadata();

// all events that are consensus or ancient have a round of -infinity
Expand Down Expand Up @@ -443,8 +445,7 @@ private boolean checkInitJudges(@NonNull final EventImpl event) {
initJudges.judgeFound(event);
logger.info(
STARTUP.getMarker(),
"Found init judge %s, num remaining: {}"
.formatted(event.getBaseEvent().getDescriptor()),
"Found init judge %s, num remaining: {}".formatted(event.shortString()),
initJudges::numMissingJudges);
if (!initJudges.allJudgesFound()) {
return false;
Expand All @@ -463,6 +464,12 @@ private boolean checkInitJudges(@NonNull final EventImpl event) {
e.setConsensus(true);
e.setRecTimes(null);
});
// This value is normally updated when a round gets decided, but since we are starting from
// a snapshot, we need to set it here.
rounds.setConsensusRelevantGeneration(initJudges.getJudges().stream()
.map(EventImpl::getGeneration)
.min(Long::compareTo)
.orElse(EventConstants.FIRST_GENERATION));
initJudges = null;

return true;
Expand Down Expand Up @@ -636,8 +643,8 @@ private void logVote(
logger.debug(
CONSENSUS_VOTING.getMarker(),
"Witness {} voted on {}. vote:{} type:{} diff:{}",
votingWitness,
candidateWitness.getWitness(),
votingWitness.shortString(),
candidateWitness.getWitness().shortString(),
votingWitness.getVote(candidateWitness),
votingType,
diff);
Expand Down Expand Up @@ -697,7 +704,7 @@ private List<EventImpl> getStronglySeenInPreviousRound(final EventImpl event) {
// Check for no judges or super majority conditions.
checkJudges(judges, decidedRoundNumber);

// update the round and generation values since fame has been decided for a new round
// update the round and ancient threshold values since fame has been decided for a new round
rounds.currentElectionDecided();

// all events that reach consensus during this method call, in consensus order
Expand All @@ -723,18 +730,8 @@ private List<EventImpl> getStronglySeenInPreviousRound(final EventImpl event) {
}
}

// Future work: prior to enabling a birth round based ancient mode, we need to use real values for
// previousRoundNonAncient and previousRoundNonExpired. This is currently a place holder.
final long previousRoundNonAncient = ConsensusConstants.ROUND_FIRST;
final long previousRoundNonExpired = ConsensusConstants.ROUND_FIRST;

final long nonAncientThreshold = ancientMode.selectIndicator(
rounds.getMinGenerationNonAncient(),
Math.max(previousRoundNonAncient, decidedRoundNumber - config.roundsNonAncient() + 1));

final long nonExpiredThreshold = ancientMode.selectIndicator(
rounds.getMinRoundGeneration(),
Math.max(previousRoundNonExpired, decidedRoundNumber - config.roundsExpired() + 1));
final long nonAncientThreshold = rounds.getAncientThreshold();
final long nonExpiredThreshold = rounds.getExpiredThreshold();

return new ConsensusRound(
roster,
Expand Down Expand Up @@ -862,7 +859,7 @@ private void setConsensusOrder(@NonNull final Collection<EventImpl> events) {
}

private boolean nonConsensusNonAncient(@NonNull final EventImpl e) {
return !e.isConsensus() && !rounds.isAncient(e);
return !e.isConsensus() && !ancient(e);
}

private @Nullable EventImpl timedStronglySeeP(@Nullable final EventImpl x, final long m) {
Expand Down Expand Up @@ -918,11 +915,12 @@ private boolean witness(@NonNull final EventImpl x) {

/**
* Check if the event is ancient
*
* @param x the event to check
* @return true if the event is ancient
*/
private boolean ancient(@Nullable final EventImpl x) {
return x == null || x.getGeneration() < rounds.getMinGenerationNonAncient();
return x == null || x.getAgeValue(ancientMode) < rounds.getAncientThreshold();
}

/**
Expand Down
4 changes: 3 additions & 1 deletion ...lds-platform-core/src/main/java/com/swirlds/platform/cli/GenesisPlatformStateCommand.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@
import com.swirlds.config.api.ConfigurationBuilder;
import com.swirlds.platform.config.DefaultConfiguration;
import com.swirlds.platform.consensus.SyntheticSnapshot;
import com.swirlds.platform.eventhandling.EventConfig;
import com.swirlds.platform.state.PlatformStateAccessor;
import com.swirlds.platform.state.service.PlatformStateFacade;
import com.swirlds.platform.state.service.WritableRosterStore;
Expand Down Expand Up @@ -70,7 +71,8 @@ public Integer call() throws IOException, ExecutionException, InterruptedExcepti
stateFacade.bulkUpdateOf(reservedSignedState.get().getState(), v -> {
System.out.printf("Replacing platform data %n");
v.setRound(PlatformStateAccessor.GENESIS_ROUND);
v.setSnapshot(SyntheticSnapshot.getGenesisSnapshot());
v.setSnapshot(SyntheticSnapshot.getGenesisSnapshot(
configuration.getConfigData(EventConfig.class).getAncientMode()));

// FUTURE WORK: remove once the AddressBook setters are deprecated and the fields are nullified.
// For now, we have to keep these calls to ensure RosterRetriever won't fall back to using these values.
Expand Down
2 changes: 1 addition & 1 deletion ...-core/src/main/java/com/swirlds/platform/components/consensus/DefaultConsensusEngine.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -113,7 +113,7 @@ public List<ConsensusRound> addEvent(@NonNull final PlatformEvent event) {
*/
@Override
public void outOfBandSnapshotUpdate(@NonNull final ConsensusSnapshot snapshot) {
final long ancientThreshold = snapshot.getMinimumGenerationNonAncient(roundsNonAncient);
final long ancientThreshold = snapshot.getAncientThreshold(roundsNonAncient);
final EventWindow eventWindow =
new EventWindow(snapshot.round(), ancientThreshold, ancientThreshold, ancientMode);

Expand Down
97 changes: 47 additions & 50 deletions ...k/swirlds-platform-core/src/main/java/com/swirlds/platform/consensus/ConsensusRounds.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
import com.hedera.hapi.node.state.roster.Roster;
import com.hedera.hapi.node.state.roster.RosterEntry;
import com.swirlds.logging.legacy.LogMarker;
import com.swirlds.platform.event.AncientMode;
import com.swirlds.platform.internal.EventImpl;
import com.swirlds.platform.roster.RosterUtils;
import com.swirlds.platform.state.MinimumJudgeInfo;
Expand All @@ -25,6 +26,8 @@ public class ConsensusRounds {
private static final Logger logger = LogManager.getLogger(ConsensusRounds.class);
/** consensus configuration */
private final ConsensusConfig config;
/** the ancient mode currently in use */
private final AncientMode ancientMode;
/** stores the minimum judge ancient identifier for all decided and non-expired rounds */
private final SequentialRingBuffer<MinimumJudgeInfo> minimumJudgeStorage;
/** a derivative of the only roster currently in use, until roster changes are implemented */
Expand All @@ -33,12 +36,21 @@ public class ConsensusRounds {
private long maxRoundCreated = ConsensusConstants.ROUND_UNDEFINED;
/** The round we are currently voting on */
private final RoundElections roundElections = new RoundElections();
/** the minimum generation of all the judges that are not ancient */
private long minGenNonAncient = EventConstants.FIRST_GENERATION;
/** the current threshold below which all events are ancient */
private long ancientThreshold = EventConstants.ANCIENT_THRESHOLD_UNDEFINED;
/**
* the minimum generation of all the judges in the latest decided round. events with a lower generation than this do
* not affect any consensus calculations
*/
private long consensusRelevantGeneration = EventConstants.GENERATION_UNDEFINED;

/** Constructs an empty object */
public ConsensusRounds(@NonNull final ConsensusConfig config, @NonNull final Roster roster) {
public ConsensusRounds(
@NonNull final ConsensusConfig config,
@NonNull final AncientMode ancientMode,
@NonNull final Roster roster) {
this.config = Objects.requireNonNull(config);
this.ancientMode = Objects.requireNonNull(ancientMode);
this.minimumJudgeStorage =
new SequentialRingBuffer<>(ConsensusConstants.ROUND_FIRST, config.roundsExpired() * 2);
this.rosterEntryMap = RosterUtils.toMap(Objects.requireNonNull(roster));
Expand All @@ -50,7 +62,8 @@ public void reset() {
minimumJudgeStorage.reset(ConsensusConstants.ROUND_FIRST);
maxRoundCreated = ConsensusConstants.ROUND_UNDEFINED;
roundElections.reset();
updateMinGenNonAncient();
updateAncientThreshold();
consensusRelevantGeneration = EventConstants.GENERATION_UNDEFINED;
}

/**
Expand Down Expand Up @@ -105,9 +118,16 @@ public void recalculating() {
* @return true if its older
*/
public boolean isOlderThanDecidedRoundGeneration(@NonNull final EventImpl event) {
return isAnyRoundDecided() // if no round has been decided, it can't be older
&& minimumJudgeStorage.get(getLastRoundDecided()).minimumJudgeAncientThreshold()
> event.getGeneration();
return consensusRelevantGeneration > event.getGeneration();
}

/**
* Setter for the {@link #consensusRelevantGeneration} field. This is used when loading consensus from a snapshot.
*
* @param consensusRelevantGeneration the value to set
*/
public void setConsensusRelevantGeneration(final long consensusRelevantGeneration) {
this.consensusRelevantGeneration = consensusRelevantGeneration;
}

/**
Expand All @@ -121,11 +141,12 @@ private boolean isAnyRoundDecided() {
* Notifies the instance that the current elections have been decided. This will start the next election.
*/
public void currentElectionDecided() {
minimumJudgeStorage.add(roundElections.getRound(), roundElections.createMinimumJudgeInfo());
minimumJudgeStorage.add(roundElections.getRound(), roundElections.createMinimumJudgeInfo(ancientMode));
consensusRelevantGeneration = roundElections.getMinGeneration();
roundElections.startNextElection();
// Delete the oldest rounds with round number which is expired
minimumJudgeStorage.removeOlderThan(getFameDecidedBelow() - config.roundsExpired());
updateMinGenNonAncient();
updateAncientThreshold();
}

/**
Expand Down Expand Up @@ -179,7 +200,7 @@ public void loadFromMinimumJudge(@NonNull final List<MinimumJudgeInfo> minimumJu
minimumJudgeStorage.add(minimumJudgeInfo.round(), minimumJudgeInfo);
}
roundElections.setRound(minimumJudgeStorage.getLatest().round() + 1);
updateMinGenNonAncient();
updateAncientThreshold();
}

/**
Expand Down Expand Up @@ -216,62 +237,38 @@ public long getMaxRound() {
}

/**
* @return The minimum judge generation number from the oldest non-expired round, if we have expired any rounds.
* Else this returns {@link EventConstants#FIRST_GENERATION}.
* Similar to {@link #getAncientThreshold()} but for expired rounds.
*
* @return the threshold for expired rounds
*/
public long getMinRoundGeneration() {
public long getExpiredThreshold() {
final MinimumJudgeInfo info = minimumJudgeStorage.get(minimumJudgeStorage.minIndex());
return info == null ? EventConstants.FIRST_GENERATION : info.minimumJudgeAncientThreshold();
return info == null ? EventConstants.ANCIENT_THRESHOLD_UNDEFINED : info.minimumJudgeAncientThreshold();
}

/**
* Update the oldest non-ancient round generation
*
* <p>Executed only on consensus thread.
* Update the current ancient threshold based on the latest round decided.
*/
private void updateMinGenNonAncient() {
if (getFameDecidedBelow() == ConsensusConstants.ROUND_FIRST) {
private void updateAncientThreshold() {
if (!isAnyRoundDecided()) {
// if no round has been decided, no events are ancient yet
minGenNonAncient = EventConstants.FIRST_GENERATION;
ancientThreshold = EventConstants.ANCIENT_THRESHOLD_UNDEFINED;
return;
}
final long nonAncientRound =
RoundCalculationUtils.getOldestNonAncientRound(config.roundsNonAncient(), getLastRoundDecided());
final MinimumJudgeInfo info = minimumJudgeStorage.get(nonAncientRound);
minGenNonAncient = info.minimumJudgeAncientThreshold();
ancientThreshold = info.minimumJudgeAncientThreshold();
}

/**
* Return the minimum generation of all the famous witnesses that are not in ancient rounds.
* Returns the threshold of all the judges that are not in ancient rounds. This is either a generation value or a
* birth round value, depending on the ancient mode configured. If no judges are ancient, returns
* {@link EventConstants#FIRST_GENERATION} or {@link ConsensusConstants#ROUND_FIRST} depending on the ancient mode.
*
* <p>Define gen(R) to be the minimum generation of all the events that were famous witnesses in
* round R.
*
* <p>If round R is the most recent round for which we have decided the fame of all the
* witnesses, then any event with a generation less than gen(R - {@code Settings.state.roundsExpired}) is called an
* “expired” event. And any non-expired event with a generation less than gen(R -
* {@code Settings.state.roundsNonAncient} + 1) is an “ancient” event. If the event failed to achieve consensus
* before becoming ancient, then it is “stale”. So every non-expired event with a generation before gen(R -
* {@code Settings.state.roundsNonAncient} + 1) is either stale or consensus, not both.
*
* <p>Expired events can be removed from memory unless they are needed for an old signed state
* that is still being used for something (such as still in the process of being written to disk).
*
* @return The minimum generation of all the judges that are not ancient. If no judges are ancient, returns
* {@link EventConstants#FIRST_GENERATION}.
*/
public long getMinGenerationNonAncient() {
return minGenNonAncient;
}

/**
* Checks if the supplied event is ancient or not. An event is ancient if its generation is smaller than the round
* generation of the oldest non-ancient round.
*
* @param event the event to check
* @return true if the event is ancient, false otherwise
* @return the threshold
*/
public boolean isAncient(@NonNull final EventImpl event) {
return event.getGeneration() < getMinGenerationNonAncient();
public long getAncientThreshold() {
return ancientThreshold;
}
}
6 changes: 3 additions & 3 deletions ...swirlds-platform-core/src/main/java/com/swirlds/platform/consensus/ConsensusSnapshot.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -113,9 +113,9 @@ public long nextConsensusNumber() {
* @param roundsNonAncient the number of non-ancient rounds
* @return minimum non-ancient generation
*/
public long getMinimumGenerationNonAncient(final int roundsNonAncient) {
return RoundCalculationUtils.getMinGenNonAncient(
roundsNonAncient, round, this::getMinimumJudgeAncientThreshold);
public long getAncientThreshold(final int roundsNonAncient) {
final long oldestNonAncientRound = RoundCalculationUtils.getOldestNonAncientRound(roundsNonAncient, round);
return getMinimumJudgeAncientThreshold(oldestNonAncientRound);
}

/**
Expand Down
21 changes: 0 additions & 21 deletions ...lds-platform-core/src/main/java/com/swirlds/platform/consensus/RoundCalculationUtils.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,6 @@
package com.swirlds.platform.consensus;

import com.swirlds.platform.system.events.EventConstants;
import java.util.function.LongUnaryOperator;

/**
* Utilities for calculating round numbers
Expand All @@ -25,24 +24,4 @@ public static long getOldestNonAncientRound(final int roundsNonAncient, final lo
// if no rounds are ancient yet, then the oldest non-ancient round is the first round ever
return Math.max(lastRoundDecided - roundsNonAncient + 1, EventConstants.MINIMUM_ROUND_CREATED);
}

/**
* Returns the minimum generation below which all events are ancient
*
* @param roundsNonAncient
* the number of non-ancient rounds
* @param lastRoundDecided
* the last round that has fame decided
* @param roundGenerationProvider
* returns a round generation number for a given round number
* @return minimum non-ancient generation
*/
public static long getMinGenNonAncient(
final int roundsNonAncient, final long lastRoundDecided, final LongUnaryOperator roundGenerationProvider) {
// if a round generation is not defined for the oldest round, it will be EventConstants.GENERATION_UNDEFINED,
// which is -1. in this case we will return FIRST_GENERATION, which is 0
return Math.max(
roundGenerationProvider.applyAsLong(getOldestNonAncientRound(roundsNonAncient, lastRoundDecided)),
EventConstants.FIRST_GENERATION);
}
}
Loading

0 comments on commit acd08f7

Please sign in to comment.