Declarative Exception Handling in ServiceMix
Ralf Wunsch wrote: We are starting a new EAI project. At this time ServiceMix is our choice for the implementation plattform. We have strong requirements for monitoring and control issues. At this one aspect is the handling of unexpected errors. For this reason i have implemented the following error handler solution. The error handling solution delegates errors or faults detected in analysis of the MessageExchange objects to an ErrorHandler implemented as XBean. This bean is used by an ErrorHandlerComponent (a JBI component embedded in the flow) or by the JBIContainer (the centralized way) or both. http://www.nabble.com/file/290/error-handler-embedding.png The ErrorHandler can cancel transactions and stop the container or the source component (all cofigurable). Furthermore it's possible to route the error or fault messages and the actuating message to a configurable target. In this case ist possible to embed one or more ErrorHandlerComponents into the flow. http://www.nabble.com/file/291/error-handler-flow.png Such an ambedded ErrorHandlerComponent borrowed by the EIP WireTap ensures that the rerouted message from the source will be in a well know format (the centralised approach can't accomplish this). The embedded and the centralized approach can be used in combination. For synchronization the ErrorHandlerComponent sets a Property on the outgoing MessageExchange and the ErrorEventListener does nothing as long as this property can be found in the MessageEchange which signals a fault or an error. A sample configuration... lt;bean id=errorHandler class=de.eval.eai.error.DefaultErrorHandlergt; lt;/beangt; ... lt;bean id=errorHandlerConfig class=de.eval.eai.error.ErrorHandlerConfiggt; lt;property name=shutdownOnFault value=true /gt; lt;property name=rollbackOnFault value=false /gt; lt;/beangt; ... lt;test:container id=jbi useMBeanServer=true createMBeanServer=false dumpStats=true statsInterval=10 errorHandler=#errorHandler errorHandlerConfig=#errorHandlerConfiggt; ... lt;sm:activationSpecsgt; ... lt;sm:activationSpec componentName=errorHandlergt; lt;sm:componentgt; lt;eai:componentgt; lt;eai:endpointsgt; lt;eai:errorHandler service=errorHandler endpoint=endpointgt; lt;eai:targetgt; lt;eai:exchange-target service=transformer /gt; lt;/eai:targetgt; lt;eai:disqualifyTargetgt; lt;eai:exchange-target service=failedQueue /gt; lt;/eai:disqualifyTargetgt; lt;eai:errorTargetgt; lt;eai:exchange-target service=errorQueue /gt; lt;/eai:errorTargetgt; lt;eai:faultTargetgt; lt;eai:exchange-target service=faultQueue /gt; lt;/eai:faultTargetgt; lt;property name=shutdownOnFault value=true /gt; lt;property name=rollbackOnFault value=false /gt; lt;/eai:errorHandlergt; lt;/eai:endpointsgt; lt;/eai:componentgt; lt;/sm:componentgt; lt;/sm:activationSpecgt; ... Two questions: Ist this a accurate ServieMix way (in accordance with the ideas of ServiceMix)? Is it on behalf of the project or the communitiy to reuse this solution? Thanks, Ralf Wunsch -- View this message in context: http://www.nabble.com/Declarative-Exception-Handling-in-ServiceMix-tf2161788.html#a6658179 Sent from the ServiceMix - Dev mailing list archive at Nabble.com.
Re: Declarative Exception Handling in ServiceMix
Sounds good. Nice work ! A few questions: * How are the errorHandler and errorHandlerConfig related ? * If I want to handle a given exception specifically, i guess I need to implement a custom errorHandler, right ? * how does the errorHandler plug into the jbi container ? If you want to donate this code, feel free to raise a JIRA issue and attach the code. I think it would be a nice addition. On 10/5/06, Ralf Wunsch [EMAIL PROTECTED] wrote: Ralf Wunsch wrote: We are starting a new EAI project. At this time ServiceMix is our choice for the implementation plattform. We have strong requirements for monitoring and control issues. At this one aspect is the handling of unexpected errors. For this reason i have implemented the following error handler solution. The error handling solution delegates errors or faults detected in analysis of the MessageExchange objects to an ErrorHandler implemented as XBean. This bean is used by an ErrorHandlerComponent (a JBI component embedded in the flow) or by the JBIContainer (the centralized way) or both. http://www.nabble.com/file/290/error-handler-embedding.png The ErrorHandler can cancel transactions and stop the container or the source component (all cofigurable). Furthermore it's possible to route the error or fault messages and the actuating message to a configurable target. In this case ist possible to embed one or more ErrorHandlerComponents into the flow. http://www.nabble.com/file/291/error-handler-flow.png Such an ambedded ErrorHandlerComponent borrowed by the EIP WireTap ensures that the rerouted message from the source will be in a well know format (the centralised approach can't accomplish this). The embedded and the centralized approach can be used in combination. For synchronization the ErrorHandlerComponent sets a Property on the outgoing MessageExchange and the ErrorEventListener does nothing as long as this property can be found in the MessageEchange which signals a fault or an error. A sample configuration... lt;bean id=errorHandler class=de.eval.eai.error.DefaultErrorHandlergt; lt;/beangt; ... lt;bean id=errorHandlerConfig class=de.eval.eai.error.ErrorHandlerConfiggt; lt;property name=shutdownOnFault value=true /gt; lt;property name=rollbackOnFault value=false /gt; lt;/beangt; ... lt;test:container id=jbi useMBeanServer=true createMBeanServer=false dumpStats=true statsInterval=10 errorHandler=#errorHandler errorHandlerConfig=#errorHandlerConfiggt; ... lt;sm:activationSpecsgt; ... lt;sm:activationSpec componentName=errorHandlergt; lt;sm:componentgt; lt;eai:componentgt; lt;eai:endpointsgt; lt;eai:errorHandler service=errorHandler endpoint=endpointgt; lt;eai:targetgt; lt;eai:exchange-target service=transformer /gt; lt;/eai:targetgt; lt;eai:disqualifyTargetgt; lt;eai:exchange-target service=failedQueue /gt; lt;/eai:disqualifyTargetgt; lt;eai:errorTargetgt; lt;eai:exchange-target service=errorQueue /gt; lt;/eai:errorTargetgt; lt;eai:faultTargetgt; lt;eai:exchange-target service=faultQueue /gt; lt;/eai:faultTargetgt; lt;property name=shutdownOnFault value=true /gt; lt;property name=rollbackOnFault value=false /gt; lt;/eai:errorHandlergt; lt;/eai:endpointsgt; lt;/eai:componentgt; lt;/sm:componentgt; lt;/sm:activationSpecgt; ... Two questions: Ist this a accurate ServieMix way (in accordance with the ideas of ServiceMix)? Is it on behalf of the project or the communitiy to reuse this solution? Thanks, Ralf Wunsch -- View this message in context: http://www.nabble.com/Declarative-Exception-Handling-in-ServiceMix-tf2161788.html#a6658179 Sent from the ServiceMix - Dev mailing list archive at Nabble.com. -- Cheers, Guillaume Nodet
Re: Declarative Exception Handling in ServiceMix
On 10/5/06, Ralf Wunsch [EMAIL PROTECTED] wrote: gnodet wrote: A few questions: * How are the errorHandler and errorHandlerConfig related ? * If I want to handle a given exception specifically, i guess I need to implement a custom errorHandler, right ? * how does the errorHandler plug into the jbi container ? * If i have more than one ErrorHandlerComponent in the flow it should be possible to use one ErrorHandler with different configurations for each ErrorHandlerComponent (e.g. to specify different targets for different types of failed messages). To provide this the configuration for the ErrorHandler has been extracted and assembled in the ErrorHandlerConfig XBean. * In my opinion the error handler hook and the handlers strategy should be separated. I am involved in a migration project (from a commercial EAI solution to open source). In the current EAI system an error handler is always implemented. We want to migrate this solution that is based on a set of database stored rules. I think there can be a lot of error handler strategy implementations. One default handler can be an implementation as discussed before. * At this time i am using my own extension of the JBIContainer. This extension registeres an ErrorEventListener as EventListener by default. I have not found a way to configure event listeners in the deployment descriptor. The ErrorHandler is a attribute of the extended container (the getter/setter methods are using the ErrorEventListerners 'errorHandler' attribute). Have you tried something like: sm:container id=jbi embedded=true sm:listeners bean class= / /sm:listeners It works. Best regards, Ralf Wunsch -- View this message in context: http://www.nabble.com/Declarative-Exception-Handling-in-ServiceMix-tf2161788.html#a6661952 Sent from the ServiceMix - Dev mailing list archive at Nabble.com. -- Cheers, Guillaume Nodet
