[
https://issues.apache.org/jira/browse/KAFKA-7873?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jason Gustafson resolved KAFKA-7873.
------------------------------------
Resolution: Fixed
Fix Version/s: 2.0.2
2.1.1
2.2.0
> KafkaBasedLog's consumer should always seek to beginning when starting
> ----------------------------------------------------------------------
>
> Key: KAFKA-7873
> URL: https://issues.apache.org/jira/browse/KAFKA-7873
> Project: Kafka
> Issue Type: Bug
> Components: KafkaConnect
> Affects Versions: 2.1.0
> Reporter: Randall Hauch
> Assignee: Randall Hauch
> Priority: Critical
> Fix For: 2.2.0, 2.1.1, 2.0.2
>
>
> KafkaBasedLog expects that callers set the `group.id` for the consumer
> configuration, and does not itself set the `group.id` if the caller does not
> explicitly do so. However,
> [KIP-289|https://cwiki.apache.org/confluence/display/KAFKA/KIP-289%3A+Improve+the+default+group+id+behavior+in+KafkaConsumer]
> changed the default for the `group.id` from a blank string to be null, which
> changes how KafkaBasedLog behaves when no `group.id` is set, and it actually
> deprecates and issues a warning when no `group.id` is specified.
> When KafkaBasedLog starts up, it should always start from the beginning of
> the topic and consume to the end. The consumer's logic for where to start is
> always:
> # explicit seek
> # committed offset (skipped if group.id is null)
> # auto reset behavior
> and currently Connect does not explicitly seek to the beginning and instead
> relies upon `auto.offset.reset=earliest`. However, if a `group.id` is
> specified *ant* there are committed offsets, then the consumer will start
> from the committed offsets rather than from the beginning. If a 'group.id' is
> not specified, then the auto reset behavior should work.
> However, to avoid the warning and possible exception when no `group.id` is
> specified, KafkaBasedLog should always call {{consumer.seekToBeginning()}}
> during startup.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
