com.hazelcast.cache.impl.journal

Interface CacheEventJournal

All Superinterfaces:

EventJournal<InternalEventJournalCacheEvent>

All Known Implementing Classes:

RingbufferCacheEventJournalImpl

public interface CacheEventJournal
extends EventJournal<InternalEventJournalCacheEvent>

The event journal is a container for events related to a data structure. This interface provides methods for cache event journals. This includes events such as add, update, remove, evict and others. Each cache and partition has it's own event journal.

If a cache is destroyed or the migrated, the related event journal will be destroyed or migrated as well. In this sense, the event journal is co-located with the cache partition and it's replicas.

NOTE : Cache evictions are based on random samples which are then compared according to an eviction policy. This is done separately on the partition owner and the backup replica and can cause different entries to be evicted on the primary and backup replica. Because of this, the record store can contain different entries and the event journal can contain eviction/remove events for different entries on different replicas. This may cause some issues if the partition owner crashes and the backup replica is promoted to the partition owner. Readers of the event journal will then continue reading from the promoted replica and may get update and remove events for entries which have already been removed.

Since:

3.9

Method Summary

Modifier and Type	Method and Description
void	writeCreatedEvent(ObjectNamespace namespace, int partitionId, Data key, Object value) Writes an CacheEventType.CREATED to the event journal.
void	writeEvictEvent(ObjectNamespace namespace, int partitionId, Data key, Object value) Writes an CacheEventType.EVICTED to the event journal.
void	writeExpiredEvent(ObjectNamespace namespace, int partitionId, Data key, Object value) Writes an CacheEventType.EXPIRED to the event journal.
void	writeRemoveEvent(ObjectNamespace namespace, int partitionId, Data key, Object value) Writes an CacheEventType.REMOVED to the event journal.
void	writeUpdateEvent(ObjectNamespace namespace, int partitionId, Data key, Object oldValue, Object newValue) Writes an CacheEventType.UPDATED to the event journal.

Methods inherited from interface com.hazelcast.journal.EventJournal

cleanup, destroy, getEventJournalConfig, getWaitNotifyKey, hasEventJournal, isAvailableOrNextSequence, isNextAvailableSequence, newestSequence, oldestSequence, readMany, toRingbufferConfig

Method Detail

writeUpdateEvent

void writeUpdateEvent(ObjectNamespace namespace,
                      int partitionId,
                      Data key,
                      Object oldValue,
                      Object newValue)

Writes an CacheEventType.UPDATED to the event journal. If there is no event journal configured for this cache, the method will do nothing. If an event is added to the event journal, all parked operations waiting for new events on that journal will be unparked.

Parameters:

namespace - the cache namespace, containing the full prefixed cache name

partitionId - the entry key partition

key - the entry key

oldValue - the old value

newValue - the new value

writeCreatedEvent

void writeCreatedEvent(ObjectNamespace namespace,
                       int partitionId,
                       Data key,
                       Object value)

Writes an CacheEventType.CREATED to the event journal. If there is no event journal configured for this cache, the method will do nothing. If an event is added to the event journal, all parked operations waiting for new events on that journal will be unparked.

Parameters:

namespace - the cache namespace, containing the full prefixed cache name

partitionId - the entry key partition

key - the entry key

value - the entry value

writeRemoveEvent

void writeRemoveEvent(ObjectNamespace namespace,
                      int partitionId,
                      Data key,
                      Object value)

Writes an CacheEventType.REMOVED to the event journal. If there is no event journal configured for this cache, the method will do nothing. If an event is added to the event journal, all parked operations waiting for new events on that journal will be unparked.

Parameters:

namespace - the cache namespace, containing the full prefixed cache name

partitionId - the entry key partition

key - the entry key

value - the entry value

writeEvictEvent

void writeEvictEvent(ObjectNamespace namespace,
                     int partitionId,
                     Data key,
                     Object value)

Writes an CacheEventType.EVICTED to the event journal. If there is no event journal configured for this cache, the method will do nothing. If an event is added to the event journal, all parked operations waiting for new events on that journal will be unparked.

Parameters:

namespace - the cache namespace, containing the full prefixed cache name

partitionId - the entry key partition

key - the entry key

value - the entry value

writeExpiredEvent

void writeExpiredEvent(ObjectNamespace namespace,
                       int partitionId,
                       Data key,
                       Object value)

Writes an CacheEventType.EXPIRED to the event journal. If there is no event journal configured for this cache, the method will do nothing. If an event is added to the event journal, all parked operations waiting for new events on that journal will be unparked.

Parameters:

namespace - the cache namespace, containing the full prefixed cache name

partitionId - the entry key partition

key - the entry key

value - the entry value