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Andriy Redko commented on CXF-8022: ----------------------------------- Thanks [~kjq], awesome. Regarding the empty response (empty stream), you are very right, yet another issue to fix (essentially, the idea is if nothing has been written yet, do not write the open and close tags, postpone it to the moment when the data become available or completion, unless the exception is raised). It also revealed the issue on the client side: when response is empty the exception is thrown inside getFlux() method instead of propagating the using the onError() callback. All fixes went into the PR, along with test cases. > Thread hangs using Reactor Flux when Exeption is Thrown > ------------------------------------------------------- > > Key: CXF-8022 > URL: https://issues.apache.org/jira/browse/CXF-8022 > Project: CXF > Issue Type: Bug > Components: JAX-RS > Affects Versions: 3.2.8, 3.3.1 > Environment: * JDK 11 > * CXF 3.3.1 > * Spring Boot (latest) > * Undertow (latest) > * Reactor (latest) > Reporter: KimJohn Quinn > Assignee: Andriy Redko > Priority: Blocker > Labels: cxf, reactor, spring-boot > Time Spent: 10m > Remaining Estimate: 0h > > We have run into a serious issue that was not expected or caught until late > it appears with CXF and Reactor in Undertow (using Spring Boot)... > The Flux throws an exception inside and hangs infinitely, requiring the > process to be forcibly killed (kill -9). > We are using Spring Boot (latest), CXF (latest) with Reactor extension, > Undertow and Reactor. Has anyone run into this and are there or could there > be any potential work around to handle this? > We wanted to stick with using CXF for both our standard REST resources and > Reactor resources because CXF has always worked well for us plus we are using > the OpenAPI swagger integration. Not being able to resolve this or have an > established workaround may cause us to have to completely revert to Spring > controllers. > There seems to be a problem with the onComplete handling of Fluxes when it > throws a RuntimeException. Basically, if you try to the endpoint, it will > hang. I've tracked it down to the writeTo function in > StreamingAsyncSubscriber where the queue is empty but "completed" is still > false so it goes into an infinite loop. You can repeat it by running the > code below. > {code:java} > @Path("/errors") > @Produces(APPLICATION_JSON) > public Flux<String> errors() > { > Flux<String> response = Flux > .range(1, 5) > .flatMap(item-> > { > if (item <=4) > { > return Mono.just("item: " + item); > } > else > { > System.out.println("---Hitting exception"); > return Mono.error(new RuntimeException("runtime > error")); > } > }); > return response; > } {code} > > I also posted this on the forums hoping someone can assist - > [http://cxf.547215.n5.nabble.com/Thread-hangs-when-using-reactor-cxf-and-undertow-td5796369.html] > > The log output, up until manually killing the process looks like: > [DEBUG] o.a.c.j.interceptor.JAXRSInInterceptor : Found operation: errors > [DEBUG] o.apache.cxf.phase.PhaseInterceptorChain : Invoking handleMessage on > interceptor org.apache.cxf.interceptor.OneWayProcessorIntercep tor@6e760b48 > [DEBUG] o.apache.cxf.phase.PhaseInterceptorChain : Invoking handleMessage on > interceptor org.apache.cxf.interceptor.ServiceInvokerIntercept or@6d7702a0 > [DEBUG] o.a.cxf.service.invoker.AbstractInvoker : Invoking method public > reactor.core.publisher.Flux io.logicdrop.drools.endpoints.DroolsR > ulesetResource.errors() on object > io.logicdrop.drools.endpoints.DroolsRulesetResource@23718909 with params []. > [DEBUG] reactor.util.Loggers$LoggerFactory : Using Slf4j logging framework > ---Hitting exception > [DEBUG] o.apache.cxf.phase.PhaseInterceptorChain : Invoking handleMessage on > interceptor org.apache.cxf.interceptor.OutgoingChainIntercepto r@308be65a > [DEBUG] o.a.c.i.OutgoingChainInterceptor : Interceptors contributed by bus: [] > [DEBUG] o.a.c.i.OutgoingChainInterceptor : Interceptors contributed by > service: [] > [DEBUG] o.a.c.i.OutgoingChainInterceptor : Interceptors contributed by > endpoint: [org.apache.cxf.interceptor.MessageSenderIntercept or@3f0061c3] > [DEBUG] o.a.c.i.OutgoingChainInterceptor : Interceptors contributed by > binding: [org.apache.cxf.jaxrs.interceptor.JAXRSOutIntercept or@5419dbea] > [DEBUG] o.apache.cxf.phase.PhaseInterceptorChain : Adding interceptor > org.apache.cxf.interceptor.MessageSenderInterceptor@3f0061c3 to phase > prepare-send > [DEBUG] o.apache.cxf.phase.PhaseInterceptorChain : Adding interceptor > org.apache.cxf.jaxrs.interceptor.JAXRSOutInterceptor@5419dbea to phas e > marshal > [DEBUG] o.apache.cxf.phase.PhaseInterceptorChain : Chain > org.apache.cxf.phase.PhaseInterceptorChain@63b5b52 was created. Current flow: > prepare-send [MessageSenderInterceptor] > marshal [JAXRSOutInterceptor] > [DEBUG] o.apache.cxf.phase.PhaseInterceptorChain : Invoking handleMessage on > interceptor org.apache.cxf.interceptor.MessageSenderIntercepto r@3f0061c3 > [DEBUG] o.apache.cxf.phase.PhaseInterceptorChain : Adding interceptor > org.apache.cxf.interceptor.MessageSenderInterceptor$MessageSenderEndi > ngInterceptor@30cf09f to phase prepare-send-ending > [DEBUG] o.apache.cxf.phase.PhaseInterceptorChain : Chain > org.apache.cxf.phase.PhaseInterceptorChain@63b5b52 was modified. Current flow: > prepare-send [MessageSenderInterceptor] > marshal [JAXRSOutInterceptor] > prepare-send-ending [MessageSenderEndingInterceptor] > [DEBUG] o.apache.cxf.phase.PhaseInterceptorChain : Invoking handleMessage on > interceptor org.apache.cxf.jaxrs.interceptor.JAXRSOutIntercept or@5419dbea > [DEBUG] o.a.c.j.interceptor.JAXRSOutInterceptor : Response content type is: > application/json > [DEBUG] o.apache.cxf.ws.addressing.ContextUtils : retrieving MAPs from > context property javax.xml.ws.addressing.context.inbound > [DEBUG] o.apache.cxf.ws.addressing.ContextUtils : WS-Addressing - failed to > retrieve Message Addressing Properties from context > Same scenario with a Mono appears to show the stream "completing"... -- This message was sent by Atlassian JIRA (v7.6.3#76005)