Interface WanConsumer.ConflictResolver

Enclosing class:

WanConsumer

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public static interface WanConsumer.ConflictResolver

Strategy for resolving conflicts when both local and remote clusters have concurrent writes to the same key.

Since:

2.0

Method Summary

Modifier and Type	Method	Description
static @NonNull WanConsumer.ConflictResolver	lastWriteWins()	Last-write-wins: keep the value with the later timestamp.
static @NonNull WanConsumer.ConflictResolver	localWins()	Always keep the local value (ignore remote writes on conflict).
static @NonNull WanConsumer.ConflictResolver	remoteWins()	Always accept the remote value (overwrite local on conflict).
byte @Nullable []	resolve(@NonNull String key, byte @Nullable [] localValue, byte @Nullable [] remoteValue, long localTimestamp, long remoteTimestamp)	Resolve a conflict between local and remote values.

Method Details

resolve

byte @Nullable [] resolve(@NonNull String key,
 byte @Nullable [] localValue,
 byte @Nullable [] remoteValue,
 long localTimestamp,
 long remoteTimestamp)

Resolve a conflict between local and remote values.

Parameters:

key - the conflicting key

localValue - the local value (may be null)

remoteValue - the remote value (may be null)

localTimestamp - epoch millis when local value was written

remoteTimestamp - epoch millis when remote value was written

Returns:

the resolved value to keep (null to delete the key)

lastWriteWins

static @NonNull WanConsumer.ConflictResolver lastWriteWins()

Last-write-wins: keep the value with the later timestamp. On tie, remote wins (bias toward convergence).

Returns:

a LWW conflict resolver

localWins

static @NonNull WanConsumer.ConflictResolver localWins()

Always keep the local value (ignore remote writes on conflict).

Returns:

a local-wins conflict resolver

remoteWins

static @NonNull WanConsumer.ConflictResolver remoteWins()

Always accept the remote value (overwrite local on conflict).

Returns:

a remote-wins conflict resolver