Ara, How do you consume your topics? Via
> builder.stream("topic1", "topic2", "topic3);
or via
> builder.stream("topic1");
> builder.stream("topic2");
> builder.stream("topic3");
Both and handled differently with regard to creating tasks (partition to
task assignment also depends on you downstream code though).
If this does not help, can you maybe share the structure of processing?
To dig deeper, we would need to know the topology DAG.
-Matthias
On 3/25/17 5:56 PM, Ara Ebrahimi wrote:
> Mathias,
>
> This apparently happens because we have more than 1 source topic. We have 3
> source topics in the same application. So it seems like the task assignment
> algorithm creates topologies not for one specific topic at a time but the
> total partitions across all source topics consumed in an application
> instance. Because we have some code dependencies between these 3 source
> topics we can’t separate them into 3 applications at this time. Hence the
> reason I want to get the task assignment algorithm basically do a uniform and
> simple task assignment PER source topic.
>
> Ara.
>
> On Mar 25, 2017, at 5:21 PM, Matthias J. Sax
> <matth...@confluent.io<mailto:matth...@confluent.io>> wrote:
>
>
>
>
> ________________________________
>
> 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
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> From: "Matthias J. Sax" <matth...@confluent.io<mailto:matth...@confluent.io>>
> Subject: Re: more uniform task assignment across kafka stream nodes
> Date: March 25, 2017 at 5:21:47 PM PDT
> To: users@kafka.apache.org<mailto:users@kafka.apache.org>
> Reply-To: <users@kafka.apache.org<mailto:users@kafka.apache.org>>
>
>
> Hi,
>
> I am wondering why this happens in the first place. Streams,
> load-balanced over all running instances, and each instance should be
> the same number of tasks (and thus partitions) assigned.
>
> What is the overall assignment? Do you have StandyBy tasks configured?
> What version do you use?
>
>
> -Matthias
>
>
> On 3/24/17 8:09 PM, Ara Ebrahimi wrote:
> Hi,
>
> Is there a way to tell kafka streams to uniformly assign partitions across
> instances? If I have n kafka streams instances running, I want each to handle
> EXACTLY 1/nth number of partitions. No dynamic task assignment logic. Just
> dumb 1/n assignment.
>
> Here’s our scenario. Lets say we have an “source" topic with 8 partitions. We
> also have 2 kafka streams instances. Each instances get assigned to handle 4
> “source" topic partitions. BUT then we do a few maps and an aggregate. So
> data gets shuffled around. The map function uniformly distributes these
> across all partitions (I can verify that by looking at the partition
> offsets). After the map what I notice by looking at the topology is that one
> kafka streams instance get assigned to handle say 2 aggregate repartition
> topics and the other one gets assigned 6. Even worse, on bigger clusters (say
> 4 instances) we see say 2 nodes gets assigned downstream aggregate
> repartition topics and 2 other nodes assigned NOTHING to handle.
>
> 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.
>
> ________________________________
>
>
>
>
>
>
>
>
> ________________________________
>
> 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
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