Hi, Shikhar
It seems you have used state V2 APIs in your code. Please check the imports in
your ```FraudDetector.java``` and you may see that ```ValueState``` and
```ValueStateDescriptor``` are under ```org.apache.flink.api.common.state.v2```
package.
About your questions:
1. The asynchronous behavior introduced in `FraudDetector` is related to state
accessing with State V2. You can refer to link[1] for more information about
State V2.
2. To fix the problem, you can either:
(1) Change the imports to the following, to use State V1
import org.apache.flink.api.common.state.ValueState;
import org.apache.flink.api.common.state.ValueStateDescriptor;
(2) Or, in your ```FraudDetectionJob```, enable async state for the keyed
stream:
DataStream<Alert> alerts = transactions
.keyBy(Transaction::getAccountId)
.enableAsyncState()
.process(new FraudDetector())
.name("fraud-detector");
For both solutions I have checked locally and they should both work.
> 2025年6月27日 20:18，Shikhar Raje <shikhar.r...@dream11.com> 写道：
>
> Hello,
>
> I am following along with this tutorial:
> https://nightlies.apache.org/flink/flink-docs-release-2.0/docs/try-flink/datastream/
>
> <https://nightlies.apache.org/flink/flink-docs-release-2.0/docs/try-flink/datastream/>
> .
>
> I am deploying this to the latest binary downloaded from:
> https://nightlies.apache.org/flink/flink-docs-release-2.0/docs/try-flink/local_installation/
>
> <https://nightlies.apache.org/flink/flink-docs-release-2.0/docs/try-flink/local_installation/>
> , which is the 2.0.0 binary.
>
> When running the Fraud Detection code, I am getting this error:
>
> Caused by: java.lang.IllegalStateException: Current operator integrates the
> async processing logic, thus only supports state v2 APIs. Please use
> StateDescriptor under 'org.apache.flink.runtime.state.v2'.
>
> So, two questions about this error message.
> 1. Following along with the code, it's not clear to me which part of the
> operator is using async . If it's possible to mix v2 and v1 APIs in
> synchronous mode, that would also work.
> 2. Looking at the Javadocs for 'org.apache.flink.runtime.state.v2', I can't
> seem to see a StateDescriptor class there:
> https://javadoc.io/doc/org.apache.flink/flink-runtime/2.0.0/org/apache/flink/runtime/state/v2/package-summary.html
>
> <https://javadoc.io/doc/org.apache.flink/flink-runtime/2.0.0/org/apache/flink/runtime/state/v2/package-summary.html>
> . So I'm not sure what is the correct import to use here?
>
> Appreciate any help in this matter!
>
> Thank You
>
> Sincerely,
> Shikhar Raje
>
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