[jira] [Comment Edited] (KAFKA-6127) Streams should never block infinitely

["Sophie Blee-Goldman (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/KAFKA-6127?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17194565#comment-17194565 ] 

Sophie Blee-Goldman edited comment on KAFKA-6127 at 9/11/20, 11:47 PM:
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[~guozhang] [~vvcephei]  any thoughts on this? You probably touched on a lot of these calls back in "The Refactor" – I remember seeing that we started to catch TimeoutException in the Consumer#position call, for example.

I know there are some related issues with infinite blocking in exceptional cases, for example when a topic is deleted out from under a Producer, but we already have a separate ticket for that. If that sort of thing is the only one remaining we should maybe close this as a duplicate instead


was (Author: ableegoldman):
[~guozhang] any thoughts on this? You probably touched on a lot of these calls back in "The Refactor" – I remember seeing that we started to catch TimeoutException in the Consumer#position call, for example.

I know there are some related issues with infinite blocking in exceptional cases, for example when a topic is deleted out from under a Producer, but we already have a separate ticket for that. If that sort of thing is the only one remaining we should maybe close this as a duplicate instead

> Streams should never block infinitely
> -------------------------------------
>
>                 Key: KAFKA-6127
>                 URL: https://issues.apache.org/jira/browse/KAFKA-6127
>             Project: Kafka
>          Issue Type: Bug
>          Components: streams
>    Affects Versions: 1.0.0
>            Reporter: Matthias J. Sax
>            Priority: Major
>              Labels: exactly-once
>
> Streams uses three consumer APIs that can block infinite: {{commitSync()}}, {{committed()}}, and {{position()}}. Also {{KafkaProducer#send()}} can block. If EOS is enabled, {{KafkaProducer#initTransactions()}} also used to block (fixed in KAFKA-6446) and we should double check the code if we handle this case correctly.
> If we block within one operation, the whole {{StreamThread}} would block, and the instance does not make any progress, becomes unresponsive (for example, {{KafkaStreams#close()}} suffers), and we also might drop out of the consumer group.
> Thanks to [KIP-266|[https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=75974886],] the Consumer now has non-blocking variants that we can use, but the same is not true of Producer. We can add non-blocking variants to Producer as well, or set the appropriate config options to set the max timeout.
> Of course, we'd also need to be sure the catch the appropriate timeout exceptions.



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