[
https://issues.apache.org/jira/browse/STORM-2914?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16346186#comment-16346186
]
Jungtaek Lim commented on STORM-2914:
-------------------------------------
[~hmclouro]
What I suggest was to simplify the processing guarantee. Most of our supporting
spouts guarantee either at-most-once or at-least-once, except exactly-once. So
for me unless the gap between none and at-most-once is huge (like performance),
I don't feel any benefit to have it and make KafkaSpout more complicated, not
considering logic, but considering maintaining cost (mainly troubleshooting).
I think we are logging message as WARN because that's the thing users should be
aware of. Based on my understanding, simply not logging at all doesn't make
sense. If it is ignorable, why it is logged as WARN? If it is the thing to
handle, why we are going to swallow?
> Remove enable.auto.commit support from storm-kafka-client
> ---------------------------------------------------------
>
> Key: STORM-2914
> URL: https://issues.apache.org/jira/browse/STORM-2914
> Project: Apache Storm
> Issue Type: Improvement
> Components: storm-kafka-client
> Affects Versions: 2.0.0, 1.2.0
> Reporter: Stig Rohde Døssing
> Assignee: Stig Rohde Døssing
> Priority: Major
> Labels: pull-request-available
> Time Spent: 20m
> Remaining Estimate: 0h
>
> The enable.auto.commit option causes the KafkaConsumer to periodically commit
> the latest offsets it has returned from poll(). It is convenient for use
> cases where messages are polled from Kafka and processed synchronously, in a
> loop.
> Due to https://issues.apache.org/jira/browse/STORM-2913 we'd really like to
> store some metadata in Kafka when the spout commits. This is not possible
> with enable.auto.commit. I took at look at what that setting actually does,
> and it just causes the KafkaConsumer to call commitAsync during poll (and
> during a few other operations, e.g. close and assign) with some interval.
> Ideally I'd like to get rid of ProcessingGuarantee.NONE, since I think
> ProcessingGuarantee.AT_MOST_ONCE covers the same use cases, and is likely
> almost as fast. The primary difference between them is that AT_MOST_ONCE
> commits synchronously.
> If we really want to keep ProcessingGuarantee.NONE, I think we should make
> our ProcessingGuarantee.NONE setting cause the spout to call commitAsync
> after poll, and never use the enable.auto.commit option. This allows us to
> include metadata in the commit.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
