Hi, AFAIK, TimeService in Flink could guarantee the semantics of "at least once/exactly once" after failure. If you only want to reload config periodically I think you could use Java native Timer yourself.
Best, Guowei Guowei Ma <guowei....@gmail.com> 于2019年4月28日周日 上午9:25写道： > Hi > AFAIK, TimeService is Flink could guarantee the semastics of > Best, > Guowei > > > Mikhail Pryakhin <m.prya...@gmail.com> 于2019年4月26日周五 下午7:57写道： > >> Hi David, >> Thank you! >> >> Yes, fair enough, but take for instance a BucketingSink class[1], it is a >> RichFunction which employs Timeservice to execute time-based logic, which >> is not directly associated with an event flow, like for example closing >> files every n minutes, etc. In an AsyncFunction I intended to use >> Timeservice the same way, like periodically reloading configuration from >> outside. >> Does it make sense? >> >> [1] >> https://github.com/apache/flink/blob/24c2e17c8d52ae2f0f897a5806a3a44fdf62b0a5/flink-connectors/flink-connector-filesystem/src/main/java/org/apache/flink/streaming/connectors/fs/bucketing/BucketingSink.java#L405 >> >> Kind Regards, >> Mike Pryakhin >> >> On 25 Apr 2019, at 10:59, Dawid Wysakowicz <dwysakow...@apache.org> >> wrote: >> >> Hi Mike, >> >> I think the reason why there is no access to TimerService in async >> function is that as it is an async function, there are no guarantees >> when/and where(at which stage of the pipeline) the function will actually >> be executed. This characteristic doesn't align with TimerService and timely >> callbacks. >> >> Best, >> >> Dawid >> On 19/04/2019 17:41, Mikhail Pryakhin wrote: >> >> Hello, Flink community! >> >> It happens that I need to access a timer service in a RichAsyncFunction >> implementation. I know it's normally accomplished via >> StreamingRuntimeContext instance available in a RichFunction, but >> unfortunately, RichAsyncFunction extending RichFunction overrides >> “setRuntimeContext” method [1] wrapping a RuntimeContext instance passed as >> the method argument into a RichAsyncFunctionRuntimeContext instance [2]. >> This RichAsyncFunction specific RuntimeContext implementation is private >> [2] which makes it infeasible to gain access to a wrapped original >> RuntimeContext thus making it impossible to leverage timer service in >> RichAsyncFunction implementations. Just curious is there any reason for >> that? Can we make this implementation public or somehow share a wrapped >> instance? >> >> Many thanks in advance! >> >> [1] >> https://github.com/apache/flink/blob/c96a4d7afe379a291cc538ca36af896df8dc2127/flink-streaming-java/src/main/java/org/apache/flink/streaming/api/functions/async/RichAsyncFunction.java#L76 >> [2] >> https://github.com/apache/flink/blob/c96a4d7afe379a291cc538ca36af896df8dc2127/flink-streaming-java/src/main/java/org/apache/flink/streaming/api/functions/async/RichAsyncFunction.java#L100 >> >> >> >> Kind Regards, >> Mike Pryakhin >> >> >>
