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From Ara Ebrahimi <ara.ebrah...@argyledata.com>
Subject Re: kafka streams consumer partition assignment is uneven
Date Mon, 09 Jan 2017 20:05:18 GMT
I meant I have 7 topics and each has 12 partitions. Considering that I have 4 streaming threads
per node, I was expecting to see each thread process 1 partition from each topics and 7 partitions
total per streaming thread. But that’s not the case. Or perhaps you are saying the number
of streaming threads should follow the total number of partitions across all 7 topics?!

Ara.

> On Jan 9, 2017, at 11:48 AM, Michael Noll <michael@confluent.io> wrote:
>
> What does the processing topology of your Kafka Streams application look
> like, and what's the exact topic and partition configuration?  You say you
> have 12 partitions in your cluster, presumably across 7 topics -- that
> means that most topics have just a single partition.  Depending on your
> topology (e.g. if you have defined that single-partition topics A, B, C
> must be joined), Kafka Streams is forced to let one of your three Streams
> nodes process "more" topics/partitions than the other two nodes.
>
> -Michael
>
>
>
> On Mon, Jan 9, 2017 at 6:52 PM, Ara Ebrahimi <ara.ebrahimi@argyledata.com>
> wrote:
>
>> Hi,
>>
>> I have 3 kafka brokers, each with 4 disks. I have 12 partitions. I have 3
>> kafka streams nodes. Each is configured to have 4 streaming threads. My
>> topology is quite complex and I have 7 topics and lots of joins and states.
>>
>> What I have noticed is that each of the 3 kafka streams nodes gets
>> configured to process variables number of partitions of a topic. One node
>> is assigned to process 2 partitions of topic a and another one gets
>> assigned 5. Hence I end up with nonuniform throughput across these nodes.
>> One node ends up processing more data than the other.
>>
>> What’s going on? How can I make sure partitions assignment to kafka
>> streams nodes is uniform?
>>
>> On a similar topic, is there a way to make sure partition assignment to
>> disks across kafka brokers is also uniform? Even if I use a round-robin one
>> to pin partitions to broker, but there doesn’t seem to be a way to
>> uniformly pin partitions to disks. Or maybe I’m missing something here? I
>> end up with 2 partitions of topic a on disk 1 and 3 partitions of topic a
>> on disk 2. It’s a bit variable. Not totally random, but it’s not uniformly
>> distributed either.
>>
>> Ara.
>>
>>
>>
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>
>
>
> ________________________________
>
> This message is for the designated recipient only and may contain privileged, proprietary,
or otherwise confidential information. If you have received it in error, please notify the
sender immediately and delete the original. Any other use of the e-mail by you is prohibited.
Thank you in advance for your cooperation.
>
> ________________________________




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This message is for the designated recipient only and may contain privileged, proprietary,
or otherwise confidential information. If you have received it in error, please notify the
sender immediately and delete the original. Any other use of the e-mail by you is prohibited.
Thank you in advance for your cooperation.

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