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Richard Yu commented on KAFKA-6127: ----------------------------------- This issue might be easier to fix now since KIP-266's PRs has been merged. I think we should rehabilitate this issue and get it resolved :). > 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. > We might consider to use {{wakeup()}} calls to unblock those operations to > keep {{StreamThread}} in a responsive state. > Note: there are discussion to add timeout to those calls, and thus, we could > get {{TimeoutExceptions}}. This would be easier to handle than using > {{wakeup()}}. Thus, we should keep an eye on those discussions. -- This message was sent by Atlassian JIRA (v7.6.3#76005)