org.axonframework.eventsourcing.eventstore.jdbc

Class JdbcEventStorageEngine.Builder

java.lang.Object

org.axonframework.eventsourcing.eventstore.AbstractEventStorageEngine.Builder

org.axonframework.eventsourcing.eventstore.BatchingEventStorageEngine.Builder

org.axonframework.eventsourcing.eventstore.jdbc.JdbcEventStorageEngine.Builder

Enclosing class:

JdbcEventStorageEngine

public static class JdbcEventStorageEngine.Builder
extends BatchingEventStorageEngine.Builder

Builder class to instantiate a JdbcEventStorageEngine.

The following configurable fields have defaults:

• The EventUpcaster defaults to an NoOpEventUpcaster.
• The PersistenceExceptionResolver is defaulted to a JdbcSQLErrorCodesResolver
• The snapshotFilter defaults to a SnapshotFilter.allowAll() instance.
• The batchSize defaults to an integer of size 100.
• The dataType is defaulted to the byte[] type.
• The EventSchema defaults to an EventSchema() call.
• The maxGapOffset defaults to an integer of size 10000.
• The lowestGlobalSequence defaults to a long of size 1.
• The gapTimeout defaults to an integer of size 60000 (1 minute).
• The gapCleaningThreshold defaults to an integer of size 250.
• The extendedGapCheckEnabled defaults to true.
• The createTokenAt defaults to JdbcEventStorageEngineStatements.createTokenAt(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.time.Instant).
• The appendEvents defaults to JdbcEventStorageEngineStatements.appendEvents(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.Class<?>, java.util.List<? extends org.axonframework.eventhandling.EventMessage<?>>, org.axonframework.serialization.Serializer, org.axonframework.eventsourcing.eventstore.jdbc.statements.TimestampWriter).
• The lastSequenceNumberFor defaults to JdbcEventStorageEngineStatements.lastSequenceNumberFor(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.String).
• The createTailToken defaults to JdbcEventStorageEngineStatements.createTailToken(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema).
• The createHeadToken defaults to JdbcEventStorageEngineStatements.createHeadToken(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema).
• The appendSnapshot defaults to JdbcEventStorageEngineStatements.appendSnapshot(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.Class<?>, org.axonframework.eventhandling.DomainEventMessage<?>, org.axonframework.serialization.Serializer, org.axonframework.eventsourcing.eventstore.jdbc.statements.TimestampWriter).
• The deleteSnapshots defaults to JdbcEventStorageEngineStatements.deleteSnapshots(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.String, long).
• The fetchTrackedEvents defaults to JdbcEventStorageEngineStatements.fetchTrackedEvents(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, long).
• The cleanGaps defaults to JdbcEventStorageEngineStatements.cleanGaps(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.util.SortedSet<java.lang.Long>).
• The readEventDataForAggregate defaults to JdbcEventStorageEngineStatements.readEventDataForAggregate(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.String, long, int).
• The readSnapshotData defaults to JdbcEventStorageEngineStatements.readSnapshotData(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, java.lang.String).
• The readEventDataWithoutGaps defaults to JdbcEventStorageEngineStatements.readEventDataWithoutGaps(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, long, int).
• The readEventDataWithGaps defaults to JdbcEventStorageEngineStatements.readEventDataWithGaps(java.sql.Connection, org.axonframework.eventsourcing.eventstore.jdbc.EventSchema, long, int, java.util.List<java.lang.Long>).

The event and snapshot Serializer, ConnectionProvider and TransactionManager are hard requirements and as such should be provided.

Field Summary

Fields inherited from class org.axonframework.eventsourcing.eventstore.AbstractEventStorageEngine.Builder

upcasterChain

Method Summary

Modifier and Type	Method and Description
JdbcEventStorageEngine.Builder	appendEvents(AppendEventsStatementBuilder appendEvents) Set the PreparedStatement to be used on JdbcEventStorageEngine.appendEvents(Connection, List, Serializer) en}.
JdbcEventStorageEngine.Builder	appendSnapshot(AppendSnapshotStatementBuilder appendSnapshot) Set the PreparedStatement to be used on JdbcEventStorageEngine.appendSnapshot(Connection, DomainEventMessage, Serializer).
JdbcEventStorageEngine.Builder	batchSize(int batchSize) Sets the batchSize specifying the number of events that should be read at each database access.
JdbcEventStorageEngine	build() Initializes a JdbcEventStorageEngine as specified through this Builder.
JdbcEventStorageEngine.Builder	cleanGaps(CleanGapsStatementBuilder cleanGaps) Set the PreparedStatement to be used on JdbcEventStorageEngine.cleanGaps(Connection, SortedSet).
JdbcEventStorageEngine.Builder	connectionProvider(ConnectionProvider connectionProvider) Sets the ConnectionProvider which provides access to a JDBC connection.
JdbcEventStorageEngine.Builder	createHeadToken(CreateHeadTokenStatementBuilder createHeadToken) Set the PreparedStatement to be used on JdbcEventStorageEngine.createHeadToken(Connection).
JdbcEventStorageEngine.Builder	createTailToken(CreateTailTokenStatementBuilder createTailToken) Set the PreparedStatement to be used on JdbcEventStorageEngine.createTailToken(Connection).
JdbcEventStorageEngine.Builder	createTokenAt(CreateTokenAtStatementBuilder createTokenAt) Set the PreparedStatement to be used on JdbcEventStorageEngine.createTokenAt.
JdbcEventStorageEngine.Builder	dataType(Class<?> dataType) Sets the dataType specifying the serialized type of the Event Message's payload and Meta Data.
JdbcEventStorageEngine.Builder	deleteSnapshots(DeleteSnapshotsStatementBuilder deleteSnapshots) Set the PreparedStatement to be used on JdbcEventStorageEngine.deleteSnapshots(Connection, String, long).
JdbcEventStorageEngine.Builder	eventSerializer(Serializer eventSerializer) Sets the Serializer used to serialize and deserialize the Event Message's payload and MetaData with.
JdbcEventStorageEngine.Builder	extendedGapCheckEnabled(boolean extendedGapCheckEnabled) Indicates whether an extra query should be performed to verify for gaps in the globalSequence larger than the configured batch size.
JdbcEventStorageEngine.Builder	fetchTrackedEvents(FetchTrackedEventsStatementBuilder fetchTrackedEvents) Set the PreparedStatement to be used on JdbcEventStorageEngine.fetchTrackedEvents(Connection, long).
JdbcEventStorageEngine.Builder	finalAggregateBatchPredicate(Predicate<List<? extends DomainEventData<?>>> finalAggregateBatchPredicate) Defines the predicate to use to recognize the terminal batch when reading an event stream for an aggregate.
JdbcEventStorageEngine.Builder	gapCleaningThreshold(int gapCleaningThreshold) Sets the threshold of number of gaps in a token before an attempt to clean gaps up is taken.
JdbcEventStorageEngine.Builder	gapTimeout(int gapTimeout) Sets the amount of time until a 'gap' in a TrackingToken may be considered timed out.
JdbcEventStorageEngine.Builder	lastSequenceNumberFor(LastSequenceNumberForStatementBuilder lastSequenceNumberFor) Set the PreparedStatement to be used on JdbcEventStorageEngine.lastSequenceNumberFor(Connection, String).
JdbcEventStorageEngine.Builder	lowestGlobalSequence(long lowestGlobalSequence) Sets the lowestGlobalSequence specifying the first expected auto generated sequence number.
JdbcEventStorageEngine.Builder	maxGapOffset(int maxGapOffset) Sets the maxGapOffset specifying the maximum distance in sequence numbers between a missing event and the event with the highest known index.
JdbcEventStorageEngine.Builder	persistenceExceptionResolver(PersistenceExceptionResolver persistenceExceptionResolver) Sets the PersistenceExceptionResolver used to detect concurrency exceptions from the backing database.
JdbcEventStorageEngine.Builder	readEventDataForAggregate(ReadEventDataForAggregateStatementBuilder readEventDataForAggregate) Set the PreparedStatement to be used on JdbcEventStorageEngine.readEventData(Connection, String, long, int).
JdbcEventStorageEngine.Builder	readEventDataWithGaps(ReadEventDataWithGapsStatementBuilder readEventDataWithGaps) Set the PreparedStatement to be used on JdbcEventStorageEngine.readEventDataWithGaps(Connection, long, int, List).
JdbcEventStorageEngine.Builder	readEventDataWithoutGaps(ReadEventDataWithoutGapsStatementBuilder readEventDataWithoutGaps) Set the PreparedStatement to be used on JdbcEventStorageEngine.readEventDataWithoutGaps(Connection, long, int).
JdbcEventStorageEngine.Builder	readSnapshotData(ReadSnapshotDataStatementBuilder readSnapshotData) Set the PreparedStatement to be used on JdbcEventStorageEngine.readSnapshotData(Connection, String).
JdbcEventStorageEngine.Builder	schema(EventSchema schema) Sets the EventSchema describing the database schema of event entries.
JdbcEventStorageEngine.Builder	snapshotFilter(Predicate<? super DomainEventData<?>> snapshotFilter) Deprecated. in favor of snapshotFilter(SnapshotFilter)
JdbcEventStorageEngine.Builder	snapshotFilter(SnapshotFilter snapshotFilter) Sets the snapshotFilter deciding whether to take a snapshot into account.
JdbcEventStorageEngine.Builder	snapshotSerializer(Serializer snapshotSerializer) Sets the Serializer used to serialize and deserialize snapshots.
JdbcEventStorageEngine.Builder	transactionManager(TransactionManager transactionManager) Sets the TransactionManager used to manage transactions around fetching event data.
JdbcEventStorageEngine.Builder	upcasterChain(EventUpcaster upcasterChain) Sets the EventUpcaster used to deserialize events of older revisions.
protected void	validate() Validates whether the fields contained in this Builder are set accordingly.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

createTokenAt

public JdbcEventStorageEngine.Builder createTokenAt(CreateTokenAtStatementBuilder createTokenAt)

Set the PreparedStatement to be used on JdbcEventStorageEngine.createTokenAt. Defaults to JdbcEventStorageEngineStatements.createTokenAt(Connection, EventSchema, Instant).

Returns:

the current Builder instance, for fluent interfacing

appendEvents

public JdbcEventStorageEngine.Builder appendEvents(AppendEventsStatementBuilder appendEvents)

Set the PreparedStatement to be used on JdbcEventStorageEngine.appendEvents(Connection, List, Serializer) en}. Defaults to JdbcEventStorageEngineStatements.appendEvents(Connection, EventSchema, Class, List, Serializer, TimestampWriter).

Returns:

the current Builder instance, for fluent interfacing

lastSequenceNumberFor

public JdbcEventStorageEngine.Builder lastSequenceNumberFor(LastSequenceNumberForStatementBuilder lastSequenceNumberFor)

Set the PreparedStatement to be used on JdbcEventStorageEngine.lastSequenceNumberFor(Connection, String). Defaults to JdbcEventStorageEngineStatements.lastSequenceNumberFor(Connection, EventSchema, String)

Returns:

the current Builder instance, for fluent interfacing

createTailToken

public JdbcEventStorageEngine.Builder createTailToken(CreateTailTokenStatementBuilder createTailToken)

Set the PreparedStatement to be used on JdbcEventStorageEngine.createTailToken(Connection). Defaults to JdbcEventStorageEngineStatements.createTailToken(Connection, EventSchema)

Returns:

the current Builder instance, for fluent interfacing

createHeadToken

public JdbcEventStorageEngine.Builder createHeadToken(CreateHeadTokenStatementBuilder createHeadToken)

Set the PreparedStatement to be used on JdbcEventStorageEngine.createHeadToken(Connection). Defaults to JdbcEventStorageEngineStatements.createHeadToken(Connection, EventSchema)

Returns:

the current Builder instance, for fluent interfacing

appendSnapshot

public JdbcEventStorageEngine.Builder appendSnapshot(AppendSnapshotStatementBuilder appendSnapshot)

Set the PreparedStatement to be used on JdbcEventStorageEngine.appendSnapshot(Connection, DomainEventMessage, Serializer). Defaults to JdbcEventStorageEngineStatements.appendEvents(Connection, EventSchema, Class, List, Serializer, TimestampWriter)

Returns:

the current Builder instance, for fluent interfacing

deleteSnapshots

public JdbcEventStorageEngine.Builder deleteSnapshots(DeleteSnapshotsStatementBuilder deleteSnapshots)

Set the PreparedStatement to be used on JdbcEventStorageEngine.deleteSnapshots(Connection, String, long). Defaults to JdbcEventStorageEngineStatements.deleteSnapshots(Connection, EventSchema, String, long)

Returns:

the current Builder instance, for fluent interfacing

fetchTrackedEvents

public JdbcEventStorageEngine.Builder fetchTrackedEvents(FetchTrackedEventsStatementBuilder fetchTrackedEvents)

Set the PreparedStatement to be used on JdbcEventStorageEngine.fetchTrackedEvents(Connection, long). Defaults to JdbcEventStorageEngineStatements.fetchTrackedEvents(Connection, EventSchema, long)

Returns:

the current Builder instance, for fluent interfacing

cleanGaps

public JdbcEventStorageEngine.Builder cleanGaps(CleanGapsStatementBuilder cleanGaps)

Set the PreparedStatement to be used on JdbcEventStorageEngine.cleanGaps(Connection, SortedSet). Defaults to JdbcEventStorageEngineStatements.cleanGaps(Connection, EventSchema, SortedSet)

Returns:

the current Builder instance, for fluent interfacing

readEventDataForAggregate

public JdbcEventStorageEngine.Builder readEventDataForAggregate(ReadEventDataForAggregateStatementBuilder readEventDataForAggregate)

Set the PreparedStatement to be used on JdbcEventStorageEngine.readEventData(Connection, String, long, int). Defaults to JdbcEventStorageEngineStatements.readEventDataForAggregate(Connection, EventSchema, String, long, int)

Returns:

the current Builder instance, for fluent interfacing

readSnapshotData

public JdbcEventStorageEngine.Builder readSnapshotData(ReadSnapshotDataStatementBuilder readSnapshotData)

Set the PreparedStatement to be used on JdbcEventStorageEngine.readSnapshotData(Connection, String). Defaults to JdbcEventStorageEngineStatements.readSnapshotData(Connection, EventSchema, String)

Returns:

the current Builder instance, for fluent interfacing

readEventDataWithoutGaps

public JdbcEventStorageEngine.Builder readEventDataWithoutGaps(ReadEventDataWithoutGapsStatementBuilder readEventDataWithoutGaps)

Set the PreparedStatement to be used on JdbcEventStorageEngine.readEventDataWithoutGaps(Connection, long, int). Defaults to JdbcEventStorageEngineStatements.readEventDataWithoutGaps(Connection, EventSchema, long, int)

Returns:

the current Builder instance, for fluent interfacing

readEventDataWithGaps

public JdbcEventStorageEngine.Builder readEventDataWithGaps(ReadEventDataWithGapsStatementBuilder readEventDataWithGaps)

Set the PreparedStatement to be used on JdbcEventStorageEngine.readEventDataWithGaps(Connection, long, int, List). Defaults to JdbcEventStorageEngineStatements.readEventDataWithGaps(Connection, EventSchema, long, int, List)

Returns:

the current Builder instance, for fluent interfacing

snapshotSerializer

public JdbcEventStorageEngine.Builder snapshotSerializer(Serializer snapshotSerializer)

Description copied from class: AbstractEventStorageEngine.Builder

Sets the Serializer used to serialize and deserialize snapshots.

Overrides:

snapshotSerializer in class BatchingEventStorageEngine.Builder

Parameters:

snapshotSerializer - a Serializer used to serialize and deserialize snapshots

Returns:

the current Builder instance, for fluent interfacing

upcasterChain

public JdbcEventStorageEngine.Builder upcasterChain(EventUpcaster upcasterChain)

Description copied from class: AbstractEventStorageEngine.Builder

Sets the EventUpcaster used to deserialize events of older revisions. Defaults to a NoOpEventUpcaster.

Overrides:

upcasterChain in class BatchingEventStorageEngine.Builder

Parameters:

upcasterChain - an EventUpcaster used to deserialize events of older revisions

Returns:

the current Builder instance, for fluent interfacing

persistenceExceptionResolver

public JdbcEventStorageEngine.Builder persistenceExceptionResolver(PersistenceExceptionResolver persistenceExceptionResolver)

Sets the PersistenceExceptionResolver used to detect concurrency exceptions from the backing database. If the persistenceExceptionResolver is not specified, persistence exceptions are not explicitly resolved. Defaults to a JdbcSQLErrorCodesResolver.

Overrides:

persistenceExceptionResolver in class BatchingEventStorageEngine.Builder

Parameters:

persistenceExceptionResolver - the PersistenceExceptionResolver used to detect concurrency exceptions from the backing database

Returns:

the current Builder instance, for fluent interfacing

eventSerializer

public JdbcEventStorageEngine.Builder eventSerializer(Serializer eventSerializer)

Description copied from class: AbstractEventStorageEngine.Builder

Sets the Serializer used to serialize and deserialize the Event Message's payload and MetaData with.

Overrides:

eventSerializer in class BatchingEventStorageEngine.Builder

Parameters:

eventSerializer - The serializer to serialize the Event Message's payload and MetaData with

Returns:

the current Builder instance, for fluent interfacing

finalAggregateBatchPredicate

public JdbcEventStorageEngine.Builder finalAggregateBatchPredicate(Predicate<List<? extends DomainEventData<?>>> finalAggregateBatchPredicate)

Defines the predicate to use to recognize the terminal batch when reading an event stream for an aggregate. The default behavior is implementation-specific.

The JdbcEventStorageEngine defaults to using an empty batch as the final batch. While this is safe, it is also relatively inefficient. When one can guarantee that no events for an aggregate are every removed from the event store, any batch smaller than the maximum batch size can be seen as the final batch.

Overrides:

finalAggregateBatchPredicate in class BatchingEventStorageEngine.Builder

Parameters:

finalAggregateBatchPredicate - The predicate that indicates whether a given batch is to be considered the final batch of an event stream.

Returns:

the current Builder instance, for fluent interfacing

snapshotFilter

@Deprecated
public JdbcEventStorageEngine.Builder snapshotFilter(Predicate<? super DomainEventData<?>> snapshotFilter)

Deprecated. in favor of snapshotFilter(SnapshotFilter)

Sets the snapshotFilter deciding whether to take a snapshot into account. Can be set to filter out specific snapshot revisions which should not be applied. Defaults to a Predicate which returns true regardless.

Overrides:

snapshotFilter in class BatchingEventStorageEngine.Builder

Parameters:

snapshotFilter - a Predicate which decides whether to take a snapshot into account

Returns:

the current Builder instance, for fluent interfacing

snapshotFilter

public JdbcEventStorageEngine.Builder snapshotFilter(SnapshotFilter snapshotFilter)

Description copied from class: AbstractEventStorageEngine.Builder

Sets the snapshotFilter deciding whether to take a snapshot into account. Can be set to filter out specific snapshot revisions which should not be applied. Defaults to SnapshotFilter.allowAll().

Note that SnapshotFilter instances can be combined and should return true if they handle a snapshot they wish to ignore.

Overrides:

snapshotFilter in class BatchingEventStorageEngine.Builder

Parameters:

snapshotFilter - a SnapshotFilter which decides whether to take a snapshot into account

Returns:

the current Builder instance, for fluent interfacing

batchSize

public JdbcEventStorageEngine.Builder batchSize(int batchSize)

Description copied from class: BatchingEventStorageEngine.Builder

Sets the batchSize specifying the number of events that should be read at each database access. When more than this number of events must be read to rebuild an aggregate's state, the events are read in batches of this size. Defaults to an integer of 100.

Tip: if you use a snapshotter, make sure to choose snapshot trigger and batch size such that a single batch will generally retrieve all events required to rebuild an aggregate's state.

Overrides:

batchSize in class BatchingEventStorageEngine.Builder

Parameters:

batchSize - an int specifying the number of events that should be read at each database access

Returns:

the current Builder instance, for fluent interfacing

connectionProvider

public JdbcEventStorageEngine.Builder connectionProvider(@Nonnull
                                                         ConnectionProvider connectionProvider)

Sets the ConnectionProvider which provides access to a JDBC connection.

Parameters:

connectionProvider - a ConnectionProvider which provides access to a JDBC connection

Returns:

the current Builder instance, for fluent interfacing

transactionManager

public JdbcEventStorageEngine.Builder transactionManager(TransactionManager transactionManager)

Sets the TransactionManager used to manage transactions around fetching event data. Required by certain databases for reading blob data.

Parameters:

transactionManager - a TransactionManager used to manage transactions around fetching event data

Returns:

the current Builder instance, for fluent interfacing

dataType

public JdbcEventStorageEngine.Builder dataType(Class<?> dataType)

Sets the dataType specifying the serialized type of the Event Message's payload and Meta Data. Defaults to the byte[] Class.

Parameters:

dataType - a Class specifying the serialized type of the Event Message's payload and Meta Data

Returns:

the current Builder instance, for fluent interfacing

schema

public JdbcEventStorageEngine.Builder schema(EventSchema schema)

Sets the EventSchema describing the database schema of event entries. Defaults to EventSchema().

Parameters:

schema - the EventSchema describing the database schema of event entries

Returns:

the current Builder instance, for fluent interfacing

maxGapOffset

public JdbcEventStorageEngine.Builder maxGapOffset(int maxGapOffset)

Sets the maxGapOffset specifying the maximum distance in sequence numbers between a missing event and the event with the highest known index. If the gap is bigger it is assumed that the missing event will not be committed to the store anymore. This event storage engine will no longer look for those events the next time a batch is fetched. Defaults to an integer of 10000 (JdbcEventStorageEngine.DEFAULT_MAX_GAP_OFFSET.

Parameters:

maxGapOffset - an int specifying the maximum distance in sequence numbers between a missing event and the event with the highest known index

Returns:

the current Builder instance, for fluent interfacing

lowestGlobalSequence

public JdbcEventStorageEngine.Builder lowestGlobalSequence(long lowestGlobalSequence)

Sets the lowestGlobalSequence specifying the first expected auto generated sequence number. For most data stores this is 1 unless the table has contained entries before. Defaults to a long of 1 (JdbcEventStorageEngine.DEFAULT_LOWEST_GLOBAL_SEQUENCE).

Parameters:

lowestGlobalSequence - a long specifying the first expected auto generated sequence number

Returns:

the current Builder instance, for fluent interfacing

gapTimeout

public JdbcEventStorageEngine.Builder gapTimeout(int gapTimeout)

Sets the amount of time until a 'gap' in a TrackingToken may be considered timed out. This setting will affect the cleaning process of gaps. Gaps that have timed out will be removed from Tracking Tokens to improve performance of reading events. Defaults to an integer of 60000 (JdbcEventStorageEngine.DEFAULT_GAP_TIMEOUT), thus 1 minute.

Parameters:

gapTimeout - an int specifying the amount of time until a 'gap' in a TrackingToken may be considered timed out

Returns:

the current Builder instance, for fluent interfacing

gapCleaningThreshold

public JdbcEventStorageEngine.Builder gapCleaningThreshold(int gapCleaningThreshold)

Sets the threshold of number of gaps in a token before an attempt to clean gaps up is taken. Defaults to an integer of 250 (JdbcEventStorageEngine.DEFAULT_GAP_CLEANING_THRESHOLD).

Parameters:

gapCleaningThreshold - an int specifying the threshold of number of gaps in a token before an attempt to clean gaps up is taken

Returns:

the current Builder instance, for fluent interfacing

extendedGapCheckEnabled

public JdbcEventStorageEngine.Builder extendedGapCheckEnabled(boolean extendedGapCheckEnabled)

Indicates whether an extra query should be performed to verify for gaps in the globalSequence larger than the configured batch size. These gaps could trick the storage engine into believing there are no more events to read, while there are still positions ahead.

This check comes at a cost of an extra query when a batch retrieval yields an empty result. This may increase database pressure when processors are at the HEAD of a stream, as each batch retrieval will result in an extra query, if there are no results.

Note that the extra query checks for the smallest globalSequence, higher than the last one seen. This query can be executed using an index, which should be a relatively cheap query for most databases.

Defaults to true

Parameters:

extendedGapCheckEnabled - whether to enable the "extended gap check". Defaults to true.

Returns:

the current Builder instance, for fluent interfacing

build

public JdbcEventStorageEngine build()

Initializes a JdbcEventStorageEngine as specified through this Builder.

Returns:

a JdbcEventStorageEngine as specified through this Builder

validate

protected void validate()
                 throws AxonConfigurationException

Validates whether the fields contained in this Builder are set accordingly.

Overrides:

validate in class BatchingEventStorageEngine.Builder

Throws:

AxonConfigurationException - if one field is asserted to be incorrect according to the Builder's specifications