kafka-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Guozhang Wang (JIRA)" <j...@apache.org>
Subject [jira] [Resolved] (KAFKA-7657) Invalid reporting of stream state in Kafka streams application
Date Sat, 05 Jan 2019 05:30:00 GMT

     [ https://issues.apache.org/jira/browse/KAFKA-7657?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel

Guozhang Wang resolved KAFKA-7657.
       Resolution: Fixed
         Assignee: Guozhang Wang
    Fix Version/s: 2.2.0

> Invalid reporting of stream state in Kafka streams application
> --------------------------------------------------------------
>                 Key: KAFKA-7657
>                 URL: https://issues.apache.org/jira/browse/KAFKA-7657
>             Project: Kafka
>          Issue Type: Bug
>          Components: streams
>    Affects Versions: 2.0.1
>            Reporter: Thomas Crowley
>            Assignee: Guozhang Wang
>            Priority: Major
>              Labels: bug
>             Fix For: 2.2.0
> We have a streams application with 3 instances running, two of which are reporting the
state of REBALANCING even after they have been running for days. Restarting the application
has no effect on the stream state.
> This seems suspect because each instance appears to be processing messages, and the kafka-consumer-groups
CLI tool reports hardly any offset lag in any of the partitions assigned to the REBALANCING
consumers. Each partition seems to be processing an equal amount of records too.
> Inspecting the state.dir on disk, it looks like the RocksDB state has been built and
hovers at the expected size on disk.
> This problem has persisted for us after we rebuilt our Kafka cluster and reset topics
+ consumer groups in our dev environment.
> There is nothing in the logs (with level set to DEBUG) in both the broker or the application
that suggests something exceptional has happened causing the application to be stuck REBALANCING.
> We are also running multiple streaming applications where this problem does not exist.
> Two differences between this application and our other streaming applications are:
>  * We have processing.guarantee set to exactly_once
>  * We are using a ValueTransformer which fetches from and puts data on a windowed state
> The REBALANCING state is returned from both polling the state method of our KafkaStreams
instance, and our custom metric which is derived from some logic in a KafkaStreams.StateListener
class attached via the setStateListener method.
> While I have provided a bit of context, before I reply with some reproducible code -
is there a simple way in which I can determine that my streams application is in a RUNNING
state without relying on the same mechanisms as used above?
> Further, given that it seems like my application is actually running - could this perhaps
be a bug to do with how the stream state is being reported (in the context of a transactional
stream using the processor API)?

This message was sent by Atlassian JIRA

View raw message