Hi, Oh, I see now. Yes indeed getKeyedStateBackened() is not exposed to the function and you can not migrate your state that way.
As far as I know yes, at the moment in order to convert everything at once (without getKeyes you still can implement lazy conversion) you would have to write your own operator. Piotrek > On 7 Jun 2018, at 15:26, Tony Wei <tony19920...@gmail.com> wrote: > > Hi Piotrek, > > I used `ProcessFunction` to implement it, but it seems that I can't call > `getKeyedStateBackend()` like `WindowOperator` did. > I found that `getKeyedStateBackend()` is the method in > `AbstractStreamOperator` and `ProcessFunction` API didn't extend it. > Dose that mean I can't look up all keys and migrate the entire previous > states to the new states in `ProcessFunction#open()`? > As I said, do I need to port `ProcessFunction` to `KeyedProcessOperator` to > migration state like the manner showed in `WindowOperator`? > > Best Regards, > Tony Wei > > 2018-06-07 20:28 GMT+08:00 Piotr Nowojski <pi...@data-artisans.com > <mailto:pi...@data-artisans.com>>: > What function are you implementing and how are you using it? > > Usually it’s enough if your function implements RichFunction (or rather > extend from AbstractRichFunction) and then you could use RichFunction#open in > the similar manner as in the code that I posted in previous message. Flink in > many places performs instanceof chekcs like: > org.apache.flink.api.common.functions.util.FunctionUtils#openFunction > > public static void openFunction(Function function, Configuration parameters) > throws Exception{ > if (function instanceof RichFunction) { > RichFunction richFunction = (RichFunction) function; > richFunction.open(parameters); > } > } > > Piotrek > > >> On 7 Jun 2018, at 11:07, Tony Wei <tony19920...@gmail.com >> <mailto:tony19920...@gmail.com>> wrote: >> >> Hi Piotrek, >> >> It seems that this was implemented by `Operator` API, which is a more low >> level api compared to `Function` API. >> Since in `Function` API level we can only migrate state by event triggered, >> it is more convenient in this way to migrate state by foreach all keys in >> `open()` method. >> If I was implemented state operator by `ProcessFunction` API, is it possible >> to port it to `KeyedProcessOperator` and do the state migration that you >> mentioned? >> And are there something concerned and difficulties that will leads to >> restored state failed or other problems? Thank you! >> >> Best Regards, >> Tony Wei >> >> 2018-06-07 16:10 GMT+08:00 Piotr Nowojski <pi...@data-artisans.com >> <mailto:pi...@data-artisans.com>>: >> Hi, >> >> General solution for state/schema migration is under development and it >> might be released with Flink 1.6.0. >> >> Before that, you need to manually handle the state migration in your >> operator’s open method. Lets assume that your OperatorV1 has a state field >> “stateV1”. Your OperatorV2 defines field “stateV2”, which is incompatible >> with previous version. What you can do, is to add a logic in open method, to >> check: >> 1. If “stateV2” is non empty, do nothing >> 2. If there is no “stateV2”, iterate over all of the keys and manually >> migrate “stateV1” to “stateV2” >> >> In your OperatorV3 you could drop the support for “stateV1”. >> >> I have once implemented something like that here: >> >> https://github.com/pnowojski/flink/blob/bfc8858fc4b9125b8fc7acd03cb3f95c000926b2/flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/WindowOperator.java#L258 >> >> <https://github.com/pnowojski/flink/blob/bfc8858fc4b9125b8fc7acd03cb3f95c000926b2/flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/WindowOperator.java#L258> >> >> Hope that helps! >> >> Piotrek >> >> >>> On 6 Jun 2018, at 17:04, TechnoMage <mla...@technomage.com >>> <mailto:mla...@technomage.com>> wrote: >>> >>> We are still pretty new to Flink and I have a conceptual / DevOps question. >>> >>> When a job is modified and we want to deploy the new version, what is the >>> preferred method? Our jobs have a lot of keyed state. >>> >>> If we use snapshots we have old state that may no longer apply to the new >>> pipeline. >>> If we start a new job we can reprocess historical data from Kafka, but that >>> can be very resource heavy for a while. >>> >>> Is there an option I am missing? Are there facilities to “patch” or >>> “purge” selectively the keyed state? >>> >>> Michael >> >> > >
