Hi, I'm actually not very familiar with the current Table API implementations but Fabian or Timo (cc'ed) should know more. I suspect very much that this is implemented like this, yes.
Best, Aljoscha > On 5. Sep 2017, at 21:14, Johannes Schulte <johannes.schu...@gmail.com> wrote: > > Hi, > > one short question I had that fits here. When using higher level streaming we > can set min and max retention time [1] which is probably used to reduce the > number of timers registered under the hood. How is this implemented, by > registering a "clamped" timer? > > Thanks, > > Johannes > > [1] > https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/table/streaming.html#idle-state-retention-time > > <https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/table/streaming.html#idle-state-retention-time> > > On Tue, Sep 5, 2017 at 5:17 PM, Aljoscha Krettek <aljos...@apache.org > <mailto:aljos...@apache.org>> wrote: > Hi, > > This is mostly correct, but you cannot register a timer in open() because we > don't have an active key there. Only in process() and onTimer() can you > register a timer. > > In your case, I would suggest to somehow clamp the timestamp to the nearest 2 > minute (or whatever) interval or to keep an extra ValueState that tells you > whether you already registered a timer. > > Best, > Aljoscha > >> On 5. Sep 2017, at 16:55, Kien Truong <duckientru...@gmail.com >> <mailto:duckientru...@gmail.com>> wrote: >> >> Hi, >> >> You can register a processing time timer inside the onTimer and the open >> function to have a timer that run periodically. >> Pseudo-code example: >> >> ValueState<Long> lastRuntime; >> >> void open() { >> ctx.timerService().registerProcessingTimeTimer(current.timestamp + 60000); >> } >> >> void onTimer() { >> // Run the periodic task >> if (lastRuntime.get() + 60000 == timeStamp) { >> periodicTask(); >> } >> // Re-register the processing time timer timer >> lastRuntime.setValue(timeStamp); >> ctx.timerService().registerProcessingTimeTimer(current.timestamp + 60000); >> } >> >> void periodicTask() >> >> For the second question, timer are already scoped by key, so you can keep a >> lastModified variable as a ValueState, >> then compare it to the timestamp provided by the timer to see if the current >> key should be evicted. >> Checkout the example on the ProcessFunction page. >> >> https://ci.apache.org/projects/flink/flink-docs-release-1.2/dev/stream/process_function.html >> >> <https://ci.apache.org/projects/flink/flink-docs-release-1.2/dev/stream/process_function.html> >> >> Best regards, >> Kien >> >> On 9/5/2017 11:49 AM, Navneeth Krishnan wrote: >>> Hi All, >>> >>> I have a streaming pipeline which is keyed by userid and then to a flatmap >>> function. I need to clear the state after sometime and I was looking at >>> process function for it. >>> >>> Inside the process element function if I register a timer wouldn't it >>> create a timer for each incoming message? >>> // schedule the next timer 60 seconds from the current event time >>> ctx.timerService().registerEventTimeTimer(current.timestamp + >>> 60000); >>> How can I get something like a clean up task that runs every 2 mins and >>> evicts all stale data? Also is there a way to get the key inside onTimer >>> function so that I know which key has to be evicted? >>> >>> Thanks, >>> Navneeth > >
