[
https://issues.apache.org/jira/browse/KAFKA-657?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13530700#comment-13530700
]
Jay Kreps commented on KAFKA-657:
---------------------------------
I wonder if you could take a look at the updated docs and see if they seem
clear. I tried to cover those, but, well, documentation is hard:
https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol
Summary:
version id is the version of this api format. In the future if we decide we
missed an important field (e.g. lastOffset) we will add it and bump the version
number and handle both cases on the server side based on the version we see.
client id is a logical name for the client that could be used across many
client servers. This is useful for logging and metrics (i.e. figuring out WHY
you are suddenly getting 5x the qps, or whatever) if you have lots of clients.
replica id is just in the fetch request and shouldn't be in this request. A
fetch request can be issued either by a normal consumer or by a replica and the
broker has slightly different behavior in each case (e.g. whether uncommitted
messages are visible...)
> Add an API to commit offsets
> ----------------------------
>
> Key: KAFKA-657
> URL: https://issues.apache.org/jira/browse/KAFKA-657
> Project: Kafka
> Issue Type: New Feature
> Reporter: Jay Kreps
> Labels: project
> Attachments: KAFKA-657v1.patch
>
>
> Currently the consumer directly writes their offsets to zookeeper. Two
> problems with this: (1) This is a poor use of zookeeper, and we need to
> replace it with a more scalable offset store, and (2) it makes it hard to
> carry over to clients in other languages. A first step towards accomplishing
> that is to add a proper Kafka API for committing offsets. The initial version
> of this would just write to zookeeper as we do today, but in the future we
> would then have the option of changing this.
> This api likely needs to take a sequence of
> consumer-group/topic/partition/offset entries and commit them all.
> It would be good to do a wiki design on how this would work and consensus on
> that first.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
