[Q/A][Java SDK (Component)] Issue with AsyncContext Exception Handling Not Triggering Consumer Retry in Dubbo Provider

[insaneXs]

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Apache Dubbo Component

Java SDK (apache/dubbo)

Details

Description:

I am experiencing an issue where using AsyncContext in a Dubbo Provider does not trigger the consumer's retry logic when an exception occurs. Instead, the exception is directly thrown to the consumer, bypassing any retry mechanism that should be in place.

Steps to Reproduce:

Implement asynchronous logic in a Dubbo Provider using AsyncContext.
Within the execution logic, intentionally cause an exception.
Use AsyncContext.write() to return the exception to the consumer.
Expected Result:

The consumer should detect the exception and initiate a retry according to its configured retry mechanism.

Actual Result:

The exception is directly thrown to the consumer without triggering any retry attempts.

Test Code:

Provider

public class DemoServiceImpl implements DemoService {
    private static final Logger logger = LoggerFactory.getLogger(DemoServiceImpl.class);

    @Override
    public String sayHello(String name) {
        final AsyncContext asyncContext = RpcContext.startAsync();
        try{
            CompletableFuture<String> future = new CompletableFuture<>();
            // mock exception
            future.completeExceptionally(new RuntimeException("Database timeout"));
            future.whenComplete((ret, exp) -> {
                asyncContext.signalContextSwitch();
                if(exp != null){
                    asyncContext.write(exp);
                }else{
                    try {
                        asyncContext.write(ret);
                    } catch (Exception e) {
                        asyncContext.write(e);
                    }
                }
            });
        } catch (Exception e) {
            asyncContext.write(e);
        }
        return null;
    }
}

Consumer

// omit
demoService.sayHello("Foo")

// Example code that showcases the issue
Environment:

Dubbo version: [2.7.18]
Java version: [1.8]
Operating System: [Mac OS X]
Additional Information:
If there are any additional configurations or logs related to the issue, they can be provided upon request.

Code of Conduct

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[insaneXs]

It seems that on the Provider side, I need to implement a Filter along with a Filter.Listener. During the Listener.onResponse() phase, I'll need to check if the RpcResult contains an exception. If an exception is present, I should throw it to ensure the appropriate handling, potentially allowing the consumer's retry mechanism to be triggered.