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https://issues.apache.org/jira/browse/SAMZA-579?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Chris Riccomini updated SAMZA-579:
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Attachment: SAMZA-579-2.patch
Attaching updated patch based on [~closeuris]'s feedback.
# Merged nextOffsets and droppedTopicAndPartitions into one map.
# Eliminated params from refreshBrokers. Every time refreshBrokers is called,
it tries to refresh any pairs in topicPartitionsAndOffsets. Whenever a broker
is assigned, the TopicAndPartition is removed from topicPartitionsAndOffsets.
# Updated abdicate and refreshDropped to manipulate topicPartitionsAndOffsets
as required.
# Added a check in refreshBrokers (inside critical section) to prevent
double-listening to a TopicandPartition.
For (3), the only places (outside the critical section) where
topicPartitionsAndOffsets is manipulated are in start() and abdicate(). Start
is safe to manipulate. Abdicate is safe as well. When a BP abdicates, it adds
the TP back into the topicPartitionsAndOffsets variable and calls
refreshBrokers. The only point where a TP is removed is in the critical
section. A TP should never be re-added to topicPartitionsAndOffsets until the
one and only BP that owned it has abdicated.
> KafkaSystemConsumer drops SSPs on failure
> -----------------------------------------
>
> Key: SAMZA-579
> URL: https://issues.apache.org/jira/browse/SAMZA-579
> Project: Samza
> Issue Type: Bug
> Components: kafka
> Affects Versions: 0.9.0
> Reporter: Chris Riccomini
> Assignee: Chris Riccomini
> Fix For: 0.9.0
>
> Attachments: SAMZA-579-0.patch, SAMZA-579-1.patch, SAMZA-579-2.patch
>
>
> While running SAMZA-394, I discovered a bug in KafkaSystemConsumer that
> causes it to stop consuming under failure scenarios. This does not cause data
> loss, but can wedge a container until it's restarted.
> The trigger appears to be when a BrokerProxy fetches from a broker that's
> still coming up, and hasn't yet claimed ownership for a TopicAndPartition.
> When the fetch fails, the BrokerProxy abdicate()s the TopicAndPartition, and
> KafkaSystemConsumer tries to refresh to get the leader. If there is no
> leader, the KafkaSystemConsumer drops the SSP. This happens in
> KafkaSystemConsumer.refreshBrokers.
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