Hi Sidney, The WARN logging you saw was from the AbstractPartitionDiscoverer which is created by FlinkKafkaConsumer itself. It has an internal consumer which shares the client.id of the actual consumer fetching data. This is a bug that we should fix.
As Rong said, this won't affect the normal operation of the consumer. It is just an AppInfo MBean for reporting some information. There might be some slight impact on the accuracy of the consumer metrics, but should be almost ignorable because the partition discoverer is quite inactive compared with the actual consumer. Thanks, Jiangjie (Becket) Qin On Mon, Mar 16, 2020 at 12:44 AM Rong Rong <walter...@gmail.com> wrote: > We also had seen this issue before running Flink apps in a shared cluster > environment. > > Basically, Kafka is trying to register a JMX MBean[1] for application > monitoring. > This is only a WARN suggesting that you are registering more than one > MBean with the same client id "consumer-1", it should not affect your > normal application behavior. > > This is most likely occurring if you have more than one Kafka consumer > within the same JVM, are you using a session cluster[2]? can you share more > on your application configuration including parallelism and slot configs? > Also based on the log, you are not configuring the "client.id" correctly. > which config key are you using? could you also share your fill Kafka > properties map? > > > -- > Rong > > [1] https://docs.oracle.com/javase/tutorial/jmx/mbeans/standard.html > [2] > https://ci.apache.org/projects/flink/flink-docs-release-1.10/ops/deployment/yarn_setup.html#flink-yarn-session > > On Sun, Mar 15, 2020 at 8:28 AM Sidney Feiner <sidney.fei...@startapp.com> > wrote: > >> Hey, >> I've been using Flink for a while now without any problems when running >> apps with a FlinkKafkaConsumer. >> All my apps have the same overall logic (consume from kafka -> transform >> event -> write to file) and the only way they differ from each other is the >> topic they read (remaining kafka config remains identical) and the way they >> transform the event. >> But suddenly, I've been starting to get the following error: >> >> >> 2020-03-15 12:13:56,911 WARN org.apache.kafka.common.utils.AppInfoParser >> - Error registering AppInfo mbean >> javax.management.InstanceAlreadyExistsException: >> kafka.consumer:type=app-info,id=consumer-1 >> at >> com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:437) >> at >> com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1898) >> >> at >> com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:966) >> >> at >> com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:900) >> >> at >> com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:324) >> >> at >> com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522) >> >> at >> org.apache.kafka.common.utils.AppInfoParser.registerAppInfo(AppInfoParser.java:62) >> >> at >> org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:805) >> >> at >> org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:659) >> >> at >> org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:639) >> >> at >> org.apache.flink.streaming.connectors.kafka.internal.KafkaPartitionDiscoverer.initializeConnections(KafkaPartitionDiscoverer.java:58) >> >> at >> org.apache.flink.streaming.connectors.kafka.internals.AbstractPartitionDiscoverer.open(AbstractPartitionDiscoverer.java:94) >> >> at >> org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumerBase.open(FlinkKafkaConsumerBase.java:505) >> >> at >> org.apache.flink.api.common.functions.util.FunctionUtils.openFunction(FunctionUtils.java:36) >> >> at >> org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator.open(AbstractUdfStreamOperator.java:102) >> >> at >> org.apache.flink.streaming.runtime.tasks.StreamTask.openAllOperators(StreamTask.java:552) >> >> at >> org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:416) >> >> at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:705) >> at org.apache.flink.runtime.taskmanager.Task.run(Task.java:530) >> at java.lang.Thread.run(Thread.java:748) >> >> >> I've tried setting the "client.id" on my consumer to a random UUID, >> making sure I don't have any duplicates but that didn't help either. >> Any idea what could be causing this? >> >> Thanks 🙂 >> >> *Sidney Feiner* */* Data Platform Developer >> M: +972.528197720 */* Skype: sidney.feiner.startapp >> >> [image: emailsignature] >> >>
