Core Configuration

This page records property names, types, defaults, and wiring boundaries. Use Configuring a Wow Application to choose values for an environment. Defaults below come from wow-spring-boot-starter configuration classes; binding defaults and runtime fallbacks are stated separately.

WowProperties

Configuration class: WowProperties; prefix: wow.

Property	Type	Default	Runtime meaning
wow.enabled	Boolean	true	Master switch; Wow auto-configuration does not apply when false
wow.context-name	String?	null	Reads the required spring.application.name when absent
wow.shutdown-timeout	Duration	60s	Shared deadline for quiescing and reverse-order shutdown of the complete WowRuntime
wow.shutdown-quiet-period	Duration	1s	Continuous idle interval required before intake closes; new activity restarts it

shutdown-timeout must be positive. shutdown-quiet-period must be non-negative and shorter than shutdown-timeout. Both must fit exactly in a signed 64-bit nanosecond value.

spring:
  application:
    name: order-service

wow:
  shutdown-timeout: 60s
  shutdown-quiet-period: 1s

BusProperties

BusProperties is reused by command, domain-event, and state-event channels.

Relative property	Type	Default	Meaning
bus.type	BusType	kafka	Selects the bus implementation for this channel
bus.local-first.enabled	Boolean	true	Composes LocalFirst when a distributed bus exists

The kafka default is only a property default. The runtime still needs the kafka-support capability and wow.kafka.bootstrap-servers; it is not evidence that Kafka is usable.

BusType

Value	Implementation required	Boundary
kafka	wow-kafka / kafka-support	Distributed Kafka bus
redis	wow-redis / redis-support	Redis Streams bus; this value must be explicit
in_memory	Base Starter	Single process and non-durable
no_op	Base Starter	Accepts calls without real message processing; only for an explicit disabled path

LocalFirst Mode

LocalFirst always sends a distributed copy while attempting local admission. The distributed copy is marked locally handled only after every targeted local receiver accepts admission. It remains eligible for distributed processing when no subscriber exists, intake is closed, or local send fails.

Behavior and failure boundary

• LocalFirst removes a broker round trip from the fast path; it is not an exactly-once guarantee.
• A handler failure after successful local admission follows that handler's retry and acknowledgement policy. It does not retroactively re-enable the distributed copy.
• no_op and in_memory have no distributed bus to compose; LocalFirst settings do not add cross-instance behavior.

Command Bus

Configuration class: CommandProperties; prefix: wow.command.

Property	Type	Default	Meaning
wow.command.bus.type	BusType	kafka	Command bus
wow.command.bus.local-first.enabled	Boolean	true	Command LocalFirst
wow.command.idempotency.enabled	Boolean	true	Enables command idempotency precheck
wow.command.idempotency.bloom-filter.ttl	Duration	1m	Bloom-filter lifetime
wow.command.idempotency.bloom-filter.expected-insertions	Long	1000000	Expected insertions
wow.command.idempotency.bloom-filter.fpp	Double	0.00001	Target false-positive probability

IdempotencyProperties

The Bloom filter is an in-process precheck, not the source of truth. When the precheck rejects, DefaultCommandGateway still confirms the duplicate through the EventStore request-id check. Disabling it installs a no-op precheck; it does not turn client retries into exactly-once delivery.

BloomFilter

wow:
  command:
    idempotency:
      enabled: true
      bloom-filter:
        ttl: 1m
        expected-insertions: 1000000
        fpp: 0.00001

Event Bus

Configuration class: EventProperties; prefix: wow.event.

Property	Type	Default
wow.event.bus.type	BusType	kafka
wow.event.bus.local-first.enabled	Boolean	true

Domain events are sent to this bus after the EventStore append succeeds. Its acknowledgement covers only the selected adapter's send boundary; it does not prove projection, processor, or saga completion.

Event Sourcing

EventStoreProperties

Configuration class: EventStoreProperties; prefix: wow.eventsourcing.store.

Property	Type	Default	Meaning
wow.eventsourcing.store.storage	StorageType	mongo	Default EventStore binding

StorageType

Value	Implementation source	Notes
mongo	mongo-support	MongoDB EventStore / SnapshotStore / query backends
redis	redis-support	Redis EventStore / SnapshotStore; no general dynamic query implementation
elasticsearch	elasticsearch-support	Elasticsearch EventStore / SnapshotStore / query backends
in_memory	Base Starter	Lost at process exit
delay	mock-support	Delayed test implementation, not a production backend

Selecting a value does not add the implementation module. Auto-configuration fails when the matching capability or application-provided binding is missing.

SnapshotProperties

Configuration class: SnapshotProperties; prefix: wow.eventsourcing.snapshot.

Property	Type	Default	Meaning
wow.eventsourcing.snapshot.enabled	Boolean	true	Enables Snapshot Dispatcher and SnapshotStore
wow.eventsourcing.snapshot.strategy	Strategy	all	Decides when to save snapshots
wow.eventsourcing.snapshot.version-offset	Int	5	Version interval for version_offset
wow.eventsourcing.snapshot.storage	StorageType	mongo	Default SnapshotStore binding

Disabling snapshots installs NoOpSnapshotStore; configuring a snapshot storage route at the same time fails startup.

Strategy

Value	Behavior
all	Save a snapshot for every processed StateEvent
version_offset	Save when the stored version trails by at least version-offset

The SNAPSHOT stage means Snapshot Dispatcher processing completed. Under version_offset, it may complete without a new snapshot write.

StorageRoutingProperties

Configuration class: StorageRoutingProperties; prefix: wow.eventsourcing.storage-routing.

Property	Type	Default
wow.eventsourcing.storage-routing.aggregates	Map<String, AggregateStorageRouteProperties>	{}

A map key is either an aggregate in the current context or a qualified context.aggregate. Each route may contain event and snapshot channels. An omitted channel falls back to the default store.

Exact property pattern	Type	Rule
wow.eventsourcing.storage-routing.aggregates.<route>.event.storage	StorageType?	Selects an EventStore type binding
wow.eventsourcing.storage-routing.aggregates.<route>.event.binding	String?	Selects a named EventStore binding
wow.eventsourcing.storage-routing.aggregates.<route>.snapshot.storage	StorageType?	Selects a SnapshotStore type binding
wow.eventsourcing.storage-routing.aggregates.<route>.snapshot.binding	String?	Selects a named SnapshotStore binding

A configured channel must set exactly one of storage and binding. An empty channel, both values, an unknown aggregate, a missing store binding, or a missing corresponding query-backend factory binding fails fast.

wow:
  eventsourcing:
    storage-routing:
      aggregates:
        order-service.Audit:
          event:
            binding: archiveEventStore
          snapshot:
            storage: mongo

State Event Bus

Configuration class: StateProperties; prefix: wow.eventsourcing.state.

Property	Type	Default
wow.eventsourcing.state.bus.type	BusType	kafka
wow.eventsourcing.state.bus.local-first.enabled	Boolean	true

StateEvents drive snapshot processing. With a distributed implementation, include this channel's lag and failures when diagnosing the SNAPSHOT stage.

Prepare Key

Configuration class: PrepareProperties; prefix: wow.prepare.

Property	Type	Default	Meaning
wow.prepare.enabled	Boolean	true	Enables PrepareKey
wow.prepare.storage	PrepareStorage	mongo	PrepareKey storage
wow.prepare.base-packages	List<String>	[]	Packages scanned for PrepareKey definitions

PrepareStorage Values

Value	Required capability
mongo	mongo-support
redis	redis-support

A purely in-memory application has no PrepareStorage implementation and must set wow.prepare.enabled: false.

Query admission

There is no query validation-mode setting. The Gateway strictly validates the final logical Query against its captured Schema; unknown fields and missing capabilities fail closed. Independent HttpQueryGuard settings control HTTP costs; see Infrastructure Configuration.

Any value of the old wow.query.schema.validation-mode property, including strict, fails startup with an instruction to remove it. CamelCase spellings are rejected too; the setting is not silently ignored.

Environment-Specific Configuration

Reference pages do not define a development or production template. For each environment, explicitly choose all three buses, EventStore, SnapshotStore, PrepareStorage, and capabilities. See Configuring a Wow Application for the task flow.

Development Environment

A fully in-memory mode must set all three buses and both stores to in_memory, and disable PrepareKey. Otherwise untouched core defaults still select Kafka and MongoDB.

Production Environment

There is no hidden production-safe default. Record the implementation, owner, durability, recovery method, and verified evidence for every channel; property defaults alone are insufficient.

Complete Configuration Example

This example is complete only for core selections. Connections, credentials, and infrastructure tuning belong outside this page.

spring:
  application:
    name: order-service

wow:
  command:
    bus:
      type: kafka
  event:
    bus:
      type: kafka
  eventsourcing:
    store:
      storage: mongo
    snapshot:
      enabled: true
      strategy: all
      storage: mongo
    state:
      bus:
        type: kafka
  prepare:
    storage: mongo