Hi Frank, By default, Flink does not remove any state. It is the responsibility of the developer to ensure that an application does not leak state. Typically, you would use timers [1] to discard state that expired and is not useful anymore.
In the last release 1.8, we added lazy cleanup strategies for State TTL (time-to-live) [2] [3]. You configure a time-to-live when you define state and state is removed if it wasn't touched for the configured interval of time. There are a bunch of config options (is read and/or write considered as touch, strict read protection, etc.). Right now, only processing time is supported. Best, Fabian [1] https://ci.apache.org/projects/flink/flink-docs-release-1.8/dev/stream/operators/process_function.html#timers [2] https://flink.apache.org/news/2019/04/09/release-1.8.0.html#new-features-and-improvements [3] https://ci.apache.org/projects/flink/flink-docs-release-1.8/dev/stream/state/state.html#state-time-to-live-ttl Am Do., 9. Mai 2019 um 15:01 Uhr schrieb Frank Wilson <fajwil...@gmail.com>: > Hi, > > In an unwindowed key stream while using event time semantics is state > stored indefinitely or does it get expired eventually (was wondering if the > state inherits the event time of the element that updated, and if it > expires when the watermark goes past it). > > Thanks, > > Frank >
