Hi I have built a tiny example project to demonstrate a problem of camel-kafka component I stumbled upon.
When a Kafka producer is used in a global exception handler, typically to route
error messages to a dead letter topic, the producer is registered at the broker
for every route.
Are the individual routes "merged" at runtime with the global exception
handlers? It is quite surprising to have 5 Kafka producers because there are 5
Routes (4 of them "private" routes to divide the logic).
However, during startup this multi-registration takes place, but always with
the same Kafka client-id. Therefore, starting from the second producer, an
InstanceAlreadyExistsException is thrown because the JMX beans the producer
creates have all the same name.
Camel 2.24.3
Kafka Client 2.0.1
The most simple workaround is to move the producer to a direct route and call
that route from the global error handler. In this case, the problem does not
occur and there seems to be only one producer.
Regards
Stephan
javax.management.InstanceAlreadyExistsException:
kafka.producer:type=app-info,id=producerExample
at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:437)
~[na:1.8.0_144]
at
com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1898)
~[na:1.8.0_144]
at
com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:966)
~[na:1.8.0_144]
at
com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:900)
~[na:1.8.0_144]
at
com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:324)
~[na:1.8.0_144]
at
com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522)
~[na:1.8.0_144]
at
org.apache.kafka.common.utils.AppInfoParser.registerAppInfo(AppInfoParser.java:62)
~[kafka-clients-2.0.1.jar:na]
at
org.apache.kafka.clients.producer.KafkaProducer.<init>(KafkaProducer.java:451)
[kafka-clients-2.0.1.jar:na]
at
org.apache.kafka.clients.producer.KafkaProducer.<init>(KafkaProducer.java:304)
[kafka-clients-2.0.1.jar:na]
at
org.apache.camel.component.kafka.KafkaProducer.doStart(KafkaProducer.java:109)
[camel-kafka-2.24.3.jar:2.24.3]
at
org.apache.camel.support.ServiceSupport.start(ServiceSupport.java:72)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.util.ServiceHelper.startService(ServiceHelper.java:75)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.impl.DeferServiceStartupListener.onCamelContextStarted(DeferServiceStartupListener.java:49)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.impl.DefaultCamelContext.safelyStartRouteServices(DefaultCamelContext.java:3868)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.impl.DefaultCamelContext.doStartOrResumeRoutes(DefaultCamelContext.java:3647)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.impl.DefaultCamelContext.doStartCamel(DefaultCamelContext.java:3488)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.impl.DefaultCamelContext$4.call(DefaultCamelContext.java:3247)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.impl.DefaultCamelContext$4.call(DefaultCamelContext.java:3243)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.impl.DefaultCamelContext.doWithDefinedClassLoader(DefaultCamelContext.java:3266)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.impl.DefaultCamelContext.doStart(DefaultCamelContext.java:3243)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.support.ServiceSupport.start(ServiceSupport.java:72)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.impl.DefaultCamelContext.start(DefaultCamelContext.java:3159)
[camel-core-2.24.3.jar:2.24.3]
at
org.apache.camel.spring.SpringCamelContext.start(SpringCamelContext.java:133)
[camel-spring-2.24.3.jar:2.24.3]
at
org.apache.camel.spring.SpringCamelContext.onApplicationEvent(SpringCamelContext.java:174)
[camel-spring-2.24.3.jar:2.24.3]
at
org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at
org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at
org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at
org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:402)
[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at
org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:359)
[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at
org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:896)
[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at
org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh(ServletWebServerApplicationContext.java:162)
[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:552)
[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
at
org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at
org.springframework.boot.SpringApplication.refresh(SpringApplication.java:743)
[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at
org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:390)
[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at
org.springframework.boot.SpringApplication.run(SpringApplication.java:312)
[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at
org.springframework.boot.SpringApplication.run(SpringApplication.java:1214)
[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at
org.springframework.boot.SpringApplication.run(SpringApplication.java:1203)
[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]
at org.apache.camel.example.Application.main(Application.java:9)
[classes/:na]
<<attachment: KafkaProducerProblem.zip>>
