[jira] [Commented] (KAFKA-3824) Docs indicate auto.commit breaks at least once delivery but that is incorrect

["kambiz shahri (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/KAFKA-3824?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15326618#comment-15326618 ] 

kambiz shahri commented on KAFKA-3824:
--------------------------------------

I read the JavaDoc (and re-read it) and compared it to the issue description to understand.

Here is the only place where auto-commit is mentioned in the JavaDoc URL mentioned in the issue description:
"If we allowed offsets to auto commit as in the previous example messages would be considered consumed after they were given out by the consumer, and it would be possible that our process could fail after we have read messages into our in-memory buffer but before they had been inserted into the database."

It is not clear (to me) from the issue description what revision 0.10. of the Consumer does, and for what use case(s) / scenario(s) for which the javaDoc description is misleading.

Furthermore, it would be good to get an explicit outline of "breaks" when applied to "...at least once delivery"; for instance, does "breaks" mean: delivery of a message will not be done at all, or done >1 time.

I found this:
https://cwiki.apache.org/confluence/display/KAFKA/Idempotent+Producer
and wondered if it applied to the changes to the Consumer; but I cannot make any assumptions about that, without doing a diff on the Consumer codebase.

> Docs indicate auto.commit breaks at least once delivery but that is incorrect
> -----------------------------------------------------------------------------
>
>                 Key: KAFKA-3824
>                 URL: https://issues.apache.org/jira/browse/KAFKA-3824
>             Project: Kafka
>          Issue Type: Improvement
>    Affects Versions: 0.10.0.0
>            Reporter: Jay Kreps
>            Assignee: kambiz shahri
>              Labels: newbie
>
> The javadocs for the new consumer indicate that auto commit breaks at least once delivery. This is no longer correct as of 0.10. 
> http://kafka.apache.org/0100/javadoc/index.html?org/apache/kafka/clients/consumer/KafkaConsumer.html



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