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Aljoscha Krettek commented on FLINK-3089: ----------------------------------------- [~StephanEwen] you were also a great proponent of state TTL. Do you think we still need it now that it is possible to do this manually with the {{ProcessFunction}}. I'm torn on the issue but I tend towards simplicity and would therefore vote against also introducing state TTL as a separate concept. > OperatorState timeout > --------------------- > > Key: FLINK-3089 > URL: https://issues.apache.org/jira/browse/FLINK-3089 > Project: Flink > Issue Type: New Feature > Components: DataStream API, State Backends, Checkpointing > Reporter: Niels Basjes > > In some usecases (webanalytics) there is a need to have a state per visitor > on a website (i.e. keyBy(sessionid) ). > At some point the visitor simply leaves and no longer creates new events (so > a special 'end of session' event will not occur). > The only way to determine that a visitor has left is by choosing a timeout, > like "After 30 minutes no events we consider the visitor 'gone'". > Only after this (chosen) timeout has expired should we discard this state. > In the Trigger part of Windows we can set a timer and close/discard this kind > of information. But that introduces the buffering effect of the window (which > in some scenarios is unwanted). > What I would like is to be able to set a timeout on a specific OperatorState > value which I can update afterwards. > This makes it possible to create a map function that assigns the right value > and that discards the state automatically. -- This message was sent by Atlassian JIRA (v6.3.15#6346)