Maximum number of unconfirmed messages, that this actor is allowed to hold in the memory. if this number is exceeded, Deliver(ActorPath, FuncInt64, Object, Boolean) will not accept more messages and it will throw MaxUnconfirmedMessagesExceededException. The default value can be configure with the 'akka.persistence.at-least-once-delivery.max-unconfirmed-messages' configuration key. This method can be overridden by implementation classes to return non-default values.

Interval between redelivery attempts. The default value can be configure with the 'akka.persistence.at-least-once-delivery.redeliver-interval' configuration key. This method can be overridden by implementation classes to return non-default values.

Maximum number of unconfirmed messages that will be sent at each redelivery burst (burst frequency is half of the redelivery interval). If there's a lot of unconfirmed messages (e.g. if the destination is not available for a long time), this helps prevent an overwhelming amount of messages to be sent at once. The default value can be configure with the 'akka.persistence.at-least-once-delivery.redelivery-burst-limit' configuration key. This method can be overridden by implementation classes to return non-default values.

Number of messages, that have not been confirmed yet.

After this number of delivery attempts a UnconfirmedWarning message will be sent to Self. The count is reset after restart. The default value can be configure with the 'akka.persistence.at-least-once-delivery.warn-after-number-of-unconfirmed-attempts' configuration key. This method can be overridden by implementation classes to return non-default values.