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https://issues.apache.org/jira/browse/KAFKA-5212?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16199778#comment-16199778
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Richard Yu commented on KAFKA-5212:
-----------------------------------
During some study after the failure of my most recent commit, there is this
approach which one would note:
1. Due to hierarchy design, heartbeat is only accessible by ConsumerCoordinator.
2. In order to pass a variable to Fetcher, ConsumerCoordinator must pass the
necessary information through ConsumerNetworkClient.
One of the easiest ways to is to define a variable with the time of the next
heartbeat (e.g. long nextHeartbeat = now + remainingMs). The variable is
defined as a private field of ConsumerNetworkClient but is defined by
ConsumerCoordinator's methods. This way, Fetcher could have access to the next
heartbeat time.
However, this is when we encounter a problem: If fetcher's poll() is concluded
(it could not yield, thus we must wait), and if the time.milliseconds() exceeds
nextHeartbeat, we must resend a heartbeat. However, the poll() method is
currently only accessible in ConsumerCoordinator. Is there a way to get around
this?
> Consumer ListOffsets request can starve group heartbeats
> --------------------------------------------------------
>
> Key: KAFKA-5212
> URL: https://issues.apache.org/jira/browse/KAFKA-5212
> Project: Kafka
> Issue Type: Bug
> Components: consumer
> Reporter: Jason Gustafson
> Assignee: Richard Yu
> Fix For: 1.1.0, 1.0.1
>
>
> The consumer is not able to send heartbeats while it is awaiting a
> ListOffsets response. Typically this is not a problem because ListOffsets
> requests are handled quickly, but in the worst case if the request takes
> longer than the session timeout, the consumer will fall out of the group.
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