Infrastructure Configuration

This page describes only configuration owned by Wow. Backend client settings such as pools, TLS, authentication, and timeouts remain owned by Spring Boot or the native client. Check the Spring Boot version used by the application instead of copying external properties into the Wow reference.

Capabilities and properties are separate gates

wow.*.enabled=true does not add an implementation to the classpath. The application must request the matching Starter capability first. Conversely, these integrations are enabled by default when their capability is present. Do not add unused capabilities in advance.

Kafka

Configuration classes: KafkaProperties, KafkaReceiverProperties; required capability: kafka-support.

Property	Type	Default	Meaning
wow.kafka.enabled	Boolean	true	Enables Kafka auto-configuration
wow.kafka.bootstrap-servers	List<String>	none; required	Bootstrap addresses for senders and receivers
wow.kafka.topic-prefix	String	wow.	Command/DomainEvent/StateEvent topic prefix
wow.kafka.properties	Map<String, String>	{}	Common Kafka producer and consumer properties
wow.kafka.producer	Map<String, String>	{}	Producer overrides; higher precedence than common properties
wow.kafka.consumer	Map<String, String>	{}	Consumer overrides; higher precedence than common properties
wow.kafka.receiver.prefetch-batches	Int	1	Reactor Kafka poll batches to prefetch
wow.kafka.receiver.max-deferred-commits	Int	1	Maximum deferred commits retained for out-of-order completion
wow.kafka.receiver.retry-attempts	Long	3	Maximum attempts for one consecutive receive-failure burst
wow.kafka.receiver.retry-backoff	Duration	10s	Minimum receiver retry backoff
wow.kafka.receiver.decode-failure-strategy	Enum	fail	fail or acknowledge

wow:
  kafka:
    bootstrap-servers: ${KAFKA_BOOTSTRAP_SERVERS}
    producer:
      acks: all
    receiver:
      decode-failure-strategy: fail

fail terminates the current receive path and enters receiver retry for an invalid record. acknowledge acknowledges and skips it. The latter abandons that record and is appropriate only with an isolation, audit, and operator-recovery path. Wow creates bus clients; the application platform still owns topics/partitions, ACLs, retention, consumer lag, backups, and offset recovery.

MongoDB

Configuration classes: MongoProperties, MongoEventStoreBatchProperties, MongoSnapshotStoreBatchProperties; required capability: mongo-support.

Property	Type	Default	Meaning
wow.mongo.enabled	Boolean	true	Enables Mongo auto-configuration
wow.mongo.auto-init-schema	Boolean	true	Initializes Wow collection/index schema at startup
wow.mongo.event-stream-database	String?	null	EventStore database; absent uses the primary Spring database
wow.mongo.snapshot-database	String?	null	SnapshotStore/query database; absent uses the primary Spring database
wow.mongo.prepare-database	String?	null	PrepareKey database; absent uses the primary Spring database

Spring Boot owns the connection through spring.mongodb.*:

spring:
  mongodb:
    uri: ${MONGODB_URI}

Both batchers are disabled by default. When enabled, they collect concurrent writes per collection.

Exact property	Default
wow.mongo.event-store-batch.enabled	false
wow.mongo.event-store-batch.max-size	128
wow.mongo.event-store-batch.max-delay	1ms
wow.mongo.event-store-batch.max-pending-appends	4096
wow.mongo.event-store-batch.lane-count	1
wow.mongo.snapshot-store-batch.enabled	false
wow.mongo.snapshot-store-batch.max-size	128
wow.mongo.snapshot-store-batch.max-delay	1ms
wow.mongo.snapshot-store-batch.max-pending-saves	4096
wow.mongo.snapshot-store-batch.lane-count	1

max-size must exceed 1, max-delay must be positive, a pending limit must be at least max-size, and lane-count must be positive. Writes for one aggregate stay on one lane. Increase lanes only with throughput evidence. auto-init-schema=true owns Wow schema initialization; it does not replace database backup, sharding design, or business-query index verification.

Redis

Configuration classes: RedisProperties, RedisStreamRecoveryProperties; required capability: redis-support.

Property	Type	Default	Meaning
wow.redis.enabled	Boolean	true	Enables Redis auto-configuration
wow.redis.message-bus.recovery.enabled	Boolean	true	Recovers abandoned pending messages in Redis Streams consumer groups
wow.redis.message-bus.recovery.min-idle-time	Duration	5m	Minimum idle time before a pending entry can be claimed
wow.redis.message-bus.recovery.interval	Duration	30s	Interval between recovery sweeps
wow.redis.message-bus.recovery.batch-size	Long	100	Pending records per page

min-idle-time and interval must be at least 1ms; batch-size must be positive. Spring Boot owns the connection through spring.data.redis.*.

spring:
  data:
    redis:
      url: ${REDIS_URL}

Pending recovery applies only to consumer-group pending entries for Wow Redis Streams buses. It is not a Redis EventStore/SnapshotStore backup and cannot restore Stream records that were trimmed or deleted. The platform still owns persistence mode, capacity, Stream trimming, consumer groups, and backup/restore.

Elasticsearch

Configuration classes: ElasticsearchProperties, ElasticsearchQueryProperties, and the two batch-property classes; required capability: elasticsearch-support.

Property	Type	Default	Meaning
wow.elasticsearch.enabled	Boolean	true	Enables Elasticsearch auto-configuration
wow.elasticsearch.auto-init-template	Boolean	true	Creates/confirms Wow event and snapshot index templates
wow.elasticsearch.compatibility-version	Int?	null	Adds REST compatibility media-type headers when configured
wow.elasticsearch.query.batch-size	Int	10000	Batch size for PIT + search_after
wow.elasticsearch.query.keep-alive	Duration	1m	PIT keep-alive refreshed by every full-query request

query.batch-size must be in 1..10000 and no greater than the target index's index.max_result_window; keep-alive must be at least 1ms. Spring Boot owns the connection through spring.elasticsearch.*:

spring:
  elasticsearch:
    uris: ${ELASTICSEARCH_URIS}

compatibility-version has no default. Set it only when the deployed topology requires Elasticsearch REST compatibility headers, and verify the value against that server. This documentation does not pin a server major version.

Exact property	Default
wow.elasticsearch.event-store-batch.enabled	false
wow.elasticsearch.event-store-batch.max-size	128
wow.elasticsearch.event-store-batch.max-delay	1ms
wow.elasticsearch.event-store-batch.max-pending-appends	4096
wow.elasticsearch.event-store-batch.lane-count	1
wow.elasticsearch.snapshot-store-batch.enabled	false
wow.elasticsearch.snapshot-store-batch.max-size	128
wow.elasticsearch.snapshot-store-batch.max-delay	1ms
wow.elasticsearch.snapshot-store-batch.max-pending-saves	4096
wow.elasticsearch.snapshot-store-batch.lane-count	1

Batch validation matches MongoDB. EventStore batching uses Bulk create. Both direct and batch SnapshotStore paths use an atomic _source.version guarded update so an older snapshot cannot overwrite a newer one. With auto-init-template=true, a failed, empty, or unacknowledged template request fails startup. Disable it only when an external platform explicitly owns templates, and retain template version and validation evidence.

When Elasticsearch is selected for SnapshotStore, Wow also looks for concrete index resources under META-INF/wow/elasticsearch/{indexName}.json or config/wow/elasticsearch/{indexName}.json. Concrete resources are processed after the generic template and before SnapshotStore creation. This mechanism is independent of auto-init-template; missing resources remain a no-op.

WebFlux

Configuration class: WebFluxProperties; required capability: webflux-support.

Property	Type	Default	Meaning
wow.webflux.enabled	Boolean	true	Enables built-in Wow HTTP route wiring
wow.webflux.global-error.enabled	Boolean	true	Registers Wow's global WebExceptionHandler
wow.webflux.batch.concurrency	Int	128	Concurrency for batch snapshot regeneration and StateEvent resend tasks
wow.webflux.batch.prefetch	Int	4	Batch-task prefetch
wow.webflux.query.max-list-size	Int	1000	List/aggregation limit; 0 removes the cap and permits limit 0
wow.webflux.query.max-page-size	Int	100	Page-size cap; 0 disables it
wow.webflux.query.max-page-window	Long	10000	page.index * page.size cap; 0 disables it
wow.webflux.query.max-filter-nodes	Int	128	FilterExpression node cap; 0 disables it
wow.webflux.query.max-filter-values	Int	1000	Value-count cap for collection filters; 0 disables it
wow.webflux.query.allow-expensive-operators	Boolean	true	Allows expensive filters, Elements, metric sorting/arithmetic, and match-all count/paged requests
wow.webflux.query.idle-timeout	Duration	10s	Maximum idle wait for the next result or completion; 0s disables it
wow.webflux.command.request.appender.agent.enabled	Boolean	true	Adds User-Agent to command context
wow.webflux.command.request.appender.ip.enabled	Boolean	true	Adds the resolved remote IP to command context

All numeric query caps must be non-negative. Ordinary page size must still be at least 1, and page offset cannot exceed Int.MAX_VALUE. allow-expensive-operators=true is the compatibility default, not capacity evidence. Test existing requests and the upgrade path before tightening it.

Batch concurrency applies per request and is shared by snapshot rebuild and StateEvent resend. Concurrent requests multiply downstream load; lower it to match application and storage capacity.

webflux-support wires built-in command, event, snapshot-query, rebuild, and compensation routes. It does not provide business authentication, authorization, or management-plane isolation. Read actual paths from the runtime OpenAPI and protect modifying operation routes with authorization, audit, rate limits, and a controlled network entry point.