Properties

Properties you can use to configure FactCast

Schemaregistry

Property	Description	Default
factcast.store.schemaRegistryUrl	if a schemaRegistryUrl is defined, FactCast goes into validating mode. The only protocols allowed here are “http”, “https”, “classpath” and “file”. Note that http(s) and file always require two slashes after the colon, e.g. “https://someserver/…” or “file:///root/folder/…”.
factcast.store.validationEnabled	Can be used for disabling Fact validation if a schemaRegistryUrl is defined. Useful for mass data ingestion.	true
factcast.store.persistentRegistry	if fetched Schema and Transformation Documents are persisted into Postgres	false
factcast.store.allowUnvalidatedPublish	If validation is enabled, this controls if publishing facts, that are not validatable (due to missing meta-data or due to missing schema in the registry) are allowed to be published or should be rejected.	false
factcast.store.schemaStoreRefreshCron	defines the cron schedule for refreshing the SchemaRegistry by querying for the latest remote changes	`/60 * * * *` (every minute)
factcast.store.allowSchemaReplace	If a schema can be replaced by an updated version from the registry (not a good idea in production environments)	false

Transformation-Registry

Property	Description	Default
factcast.store.persistentTransformationCache	if Transformed Fact payloads are persistently cached into Postgres	false
factcast.store.inMemTransformationCacheCapacity	when using the inmem impl of the transformation cache, this is the max number of entries cached. The minimum value here is 100.	100
factcast.store.deleteTransformationsStaleForDays	when using the persistent impl of the transformation cache, this is the min number of days a transformation result is not read in order to be considered stale. This should free some space in a regular cleanup job. Must be a positive number.	14
factcast.store.transformationCacheCompactCron	defines the cron schedule for compacting the transformation result cache	`0 0 0 * * *` (at midnight)

Performance / Reliability

Property	Description	Default
factcast.store.factNotificationBlockingWaitTimeInMillis	Controls how long to block waiting for new notifications from the database (Postgres LISTEN/ NOTIFY mechanism). When this time exceeds the notifications is repeated. Minimum value is 5000.	15000 (15sec)
factcast.store.factNotificationMaxRoundTripLatencyInMillis	When FactCast did not receive any notifications after factNotificationBlockingWaitTimeInMillis milliseconds it validates the health of the database connection. For this purpose it sends an internal notification to the database and waits for the given time to receive back an answer. If the time is exceeded the database connection is renewed. Minimum value is 50.	200
factcast.store.factNotificationNewConnectionWaitTimeInMillis	how much time to wait between invalidating and acquiring a new connection. note: This parameter is only applied in the part of FactCast which deals with receiving and forwarding database notifications. Minimum value is 10.	100
factcast.store.page-size	How many Facts to fetch from the database in one go. Higher values mean more memory usage. Must be positive.	50
factcast.store.catchup-strategy	FETCHING uses database cursors where PAGED uses separate queries on TEMPORARY tables. FETCHING tends to be faster.	FETCHING
factcast.store.indexCheckCron	Cron expression defining a routine check for index validity	`0 0 3 * * *` (3 am)
factcast.store.tailIndexingEnabled	enable/ disable tail indexing	false
factcast.store.tailManagementCron	cron schedule when tail rotation should be carried out	`0 0 0 * * *` (at midnight)
factcast.store.tailGenerationsToKeep	the number of tail indexes to keep. The higher the number, the slower the inserts. Probably 2 or 3 is a good value unless you have a very high tail rebuild frequency and not permanently connected applications (like offline clients for instance). Must be a positive number, maximum is 128.	3
factcast.store.minimumTailAge	minimum age of the youngest tail index, before a new one is created	7 days
factcast.store.tailCreationTimeout	Index creation can hang for a long time in case of many open transactions. To avoid this, you can specify a timeout. We will subtract 5 seconds from the given duration before applying it to setTimeout.	`1d`
factcast.store.transformationCachePageSize	Defines the max number of Facts being scheduled for transformation in one go. Must be positive and not exceed 32000.	100
factcast.store.sizeOfThreadPoolForSubscriptions	This is the number of threads we create for handling new subscriptions requests. It’s implemented via a fixed thread pool. As soon as the subscription request finishes or enters phase 3 (follow) the thread is freed up again. In earlier versions we used the common FJP which limits the parallelism to the number of cores - 1. If you ever encounter too much database load or too high waiting time for subscriptions this can be an option.	100
factcast.store.sizeOfThreadPoolForBufferedTransformations	This is the number of threads we create for handling buffered transformations. It’s implemented via work stealing thread pool. In early versions we used the common FJP which limits the parallelism to the number of cores - 1.	25
factcast.store.readOnlyModeEnabled	Configures the FacCast to work in read-only mode. You cannot publish any events in this mode and certain functionality like tail index generation or state token generation is disabled. You can still use a persistent schema store or transformation cache, however they will work in read-only mode. Additionally, liquibase is disabled.	false

Snapshots

Property	Description	Default
factcast.store.deleteSnapshotStaleForDays	min number of days a snapshot is kept even though it is not read anymore. Must be a positive number.	90
factcast.store.snapshotCacheCompactCron	defines the cron schedule for compacting the snapshot cache	`0 0 0 * * *` (at midnight)

RedisSnapshots

Property	Description	Default
factcast.redis.deleteSnapshotStaleForDays	min number of days a snapshot is kept even though it is not read anymore. Must be a positive number.	90
factcast.redis.snapshotCacheRedissonCodec	optional configuration of the codec used for serializing objects from and into the snapshot. When set to `RedissonDefault` no codec is specified and Redisson will use its current default.	MarshallingCodec

gRPC

Properties you can use to configure gRPC:

gRPC Client

Property	Description	Default	Example
grpc.client.factstore.credentials	Credentials in the form of username:secret	none	myUserName:mySecretPassword
grpc.client.factstore.address	the address(es) fo the factcast server	none	static://localhost:9090
grpc.client.factstore.negotiationType	Usage of TLS or Plaintext?	TLS	PLAINTEXT
grpc.client.factstore.enable-keep-alive	Configures whether keepAlive should be enabled. Recommended for long running (follow) subscriptions	false	true
grpc.client.factstore.keep-alive-time	The default delay before sending keepAlives. Defaults to 60s. Please note that shorter intervals increase the network burden for the server.		300
grpc.client.factstore.keep-alive-without-calls	Configures whether keepAlive will be performed when there are no outstanding RPCs on a connection.	false	true

gRPC Client recommended settings

grpc.client.factstore.enable-keep-alive=true
grpc.client.factstore.keep-alive-time=300
grpc.client.factstore.keep-alive-without-calls=true

Further details can be found here : net.devh.boot.grpc.client.config.GrpcChannelProperties.

FactCast client specific

Property	Description	Default	Example
factcast.grpc.client.id	Server-side logging mentions this optional id if set in order to help with debugging. If this property is not set, it falls back to the value of spring.application.name	${spring.application.name}	myClient
factcast.grpc.client.catchup-batchsize	Request a batchsize in catchup phase. Produces larger message and better compression. Remember that this setting increases the memory requirements, as well as the individual message size so depending on you Fact-payload size, and this setting, you may want to increase the allowed max-in/out limits of GRPC (defaulting to ~4mb per message). Our tests have shown that values >100 seem to have an insignificant impact - your mileage may vary. Setting is valid since 0.3.9.	50	100
factcast.grpc.client.enable-fast-forward	If the server supports it, enables fast forwarding. This is supposed to speedup frequent queries that cluster around the end of the global Fact-Stream and thus can use dedicated temporary rolling indexes.	true	false
factcast.grpc.client.resilience.enabled	Enables resilience mode for subscriptions. If enabled, subscriptions that fail due to networking errors will be transparently resubscribed. (since 0.5.5)	true	false
factcast.grpc.client.resilience.window	Defines the window in which a maximum of retries is defined. (since 0.5.5)	PT30S (30 seconds)	PT2M (2 Minutes)
factcast.grpc.client.resilience.attempts	Defines the maximum number of attempts that will be done (within a time window defined by resilience.window) before failing and escalating the last exception to the application. (since 0.5.5)	10	25
factcast.grpc.client.resilience.interval	Defines the wait time between two attempts. (since 0.5.5)	PT0.1S (100 millis)	PT0.5S
factcast.grpc.client.ignore-duplicate-facts	Ignores and skips duplicate exceptions during publishing (does not include conditional publishing when using locks). This might be convenient in cases where you published to a factcast server and get a connection error back (you cannot possibly know if the publish on the server succeeded or not). If you have resilience enabled, the publish would be retried and might (if the first was successful) result in a DuplicateFactException. Setting this to true will make factcast just ignore the exception and go on. There might be a performance problem resulting from this: If you publish a batch of facts and a DuplicateFactException is recieved, factcast will fall back to publishing every single Fact from the batch one-by-one in order to make sure, that after your call, all Facts that are not duplicates will be published.	false	true

grpc Server

Property	Description	Default	Example
grpc.server.permit-keep-alive-without-calls	Configures whether clients are allowed to send keep-alive HTTP/2 PINGs even if there are no outstanding RPCs on the connection	false	true
grpc.server.permit-keep-alive-time	Specifies the most aggressive keep-alive time in seconds clients are permitted to configure. Defaults to 5min.	300	100
factcast.grpc.bandwith.numberOfFollowRequestsAllowedPerClientPerMinute	after the given number of follow requests from the same client per minute, subscriptions are rejected with RESOURCE_EXHAUSTED	5	5
factcast.grpc.bandwith.initialNumberOfFollowRequestsAllowedPerClient	ramp-up to compensate for client startup	50	50
factcast.grpc.bandwith.numberOfCatchupRequestsAllowedPerClientPerMinute	after the given number of catchup requests from the same client per minute, subscriptions are rejected with RESOURCE_EXHAUSTED	6000	6000
factcast.grpc.bandwith.initialNumberOfCatchupRequestsAllowedPerClient	ramp-up to compensate for client startup	36000	36000
factcast.grpc.bandwith.disabled	completely disables checking if set to true	false	true

gRPC Server recommended settings

grpc.server.permit-keep-alive-without-calls=true
grpc.server.permit-keep-alive-time=100

Blacklist

Property	Description	Default	Example
factcast.blacklist.type	Configures where the list of blacklisted facts is retrieved from. One of [POSTGRES, RESOURCE].	POSTGRES	—
factcast.blacklist.location	Only required if type=RESOURCE. Specifies the URL where the JSON file containing the blacklist is located.	classpath:blacklist.json	file:/some/path/blocked-facts.json

Testing

Property	Description	Default
factcast.store.integrationTestMode	when set to true, disables all non-essential memory-internal caches, timing might differ to production of course.	false

UI

Property	Description	Default
vaadin.productionMode	Should be set to true, otherwise vaadin tries to generate a dev bundle which is not necessary, and probably will fail.	false

Further details can be found here : net.devh.boot.grpc.server.config.GrpcServerProperties.

Last modified December 7, 2023 : wip (b8e62d997)