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https://issues.apache.org/jira/browse/KAFKA-10888?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17458258#comment-17458258
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nk2242696 commented on KAFKA-10888:
-----------------------------------
[~showuon] [~hachikuji]
I propose a solution based on keeping the track of number of offsets/messages
written to each partition.
# At partitioner level, Store the number of offsets/messages written to each
partition. (sizePerPartitionMap) and total(total offsets for a topic)
# Before choosing next batch to write(onNextBatch()) . Use
(sizePerPartitionMap) to blacklisting the available partitions which causes
skewness(USING a configurable THRESHOLD %) . Choose next partition from list of
available whitelisted partitions.
# To configure sizePerPartitionMap. Use the callback method of producer.send()
to update the sizePerPartitionMap and total .
This way, we can skip slower partitions(blacklisted) for few rounds and ensure
all partitions are roughly of equal size.
> Sticky partition leads to uneven product msg, resulting in abnormal delays
> in some partitions
> ----------------------------------------------------------------------------------------------
>
> Key: KAFKA-10888
> URL: https://issues.apache.org/jira/browse/KAFKA-10888
> Project: Kafka
> Issue Type: Bug
> Components: clients, producer
> Affects Versions: 2.4.1
> Reporter: jr
> Assignee: Luke Chen
> Priority: Major
> Attachments: image-2020-12-24-21-05-02-800.png,
> image-2020-12-24-21-09-47-692.png, image-2020-12-24-21-10-24-407.png
>
>
> 110 producers ,550 partitions ,550 consumers , 5 nodes Kafka cluster
> The producer uses the nullkey+stick partitioner, the total production rate
> is about 100w tps
> Observed partition delay is abnormal and message distribution is uneven,
> which leads to the maximum production and consumption delay of the partition
> with more messages
> abnormal.
> I cannot find reason that stick will make the message distribution uneven
> at this production rate.
> I can't switch to the round-robin partitioner, which will increase the
> delay and cpu cost. Is thathe stick partationer design cause uneven message
> distribution, or this is abnormal. How to solve it?
> !image-2020-12-24-21-09-47-692.png!
> As shown in the picture, the uneven distribution is concentrated on some
> partitions and some brokers, there seems to be some rules.
> This problem does not only occur in one cluster, but in many high tps
> clusters,
> The problem is more obvious on the test cluster we built.
> !image-2020-12-24-21-10-24-407.png!
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