Hi, This is known issue. Check below links for related discussion
https://issues.apache.org/jira/browse/KAFKA-3494 https://qnalist.com/questions/6420696/discuss-mbeans-overwritten-with-identical-clients-on-a-single-jvm Manikumar On Wed, May 11, 2016 at 7:29 PM, Paul Mackles <pmack...@adobe.com> wrote: > Hi > > > I have an app that spins up multiple threads in a single JVM. Each thread > has its own v9 consumer running under different groupIds. > > > Since they are part of the same application, I set the client.id property > for all 3 consumers to "frylock". > > > Everything runs OK but I do see the following exception logged as a > warning during startup: > > > 2016-05-10 06:45:12,704 WARN [nioEventLoopGroup-3-3] > org.apache.kafka.common.utils.AppInfoParser: Error registering AppInfo mbean > > javax.management.InstanceAlreadyExistsException: > kafka.consumer:type=app-info,id=frylock > > > From what I can gather, this error occurs when the consumer tries to > register the metrics with JMX. > > > I also noticed that if I don't set client.id explicitly, the API will > generate a unique client.id for each consumer. > > > So as far as the metrics are concerned, it seems like the API wants you to > set client.id to a unique value for all consumers running in the same JVM. > > > At some point, I plan to make use of quotas. As I understand it, quotas > are based on client.id. If so, it seems like the metrics handling in the > consumer API is incompatible with quotas because for quotas to work, you > would want all of the consumers that are part of the same app to use the > same client.id (even if they are running in the same JVM). > > > For my application, quotas are more important so my plan is to set > client.id=frylock for all consumers and then write-off/ignore the per > client-id JMX beans since they are probably not accurate. I guess I can > still get individual consumer metrics through the Consumer.metrics() if I > need them. > > > Anyone have any better ideas? Am I missing something? Is this > inconsistency worth filing a ticket over? > > > Thanks, > > Paul > >
